Introduction to Psychological Science: Integrating Behavioral, Neuroscience and Evolutionary Perspectives - William J. Ray 2021

Developmental Processes

LEARNING OBJECTIVES

✵ 4.1 Discuss the brain, sensory, and motor developments that take place during infancy.

✵ 4.2 Discuss cognitive development based on the theories of Piaget and Vygotsky.

✵ 4.3 Describe the aspects of social development and how we make emotional and social connections with others.

✵ 4.4 Discuss the physical, psychological, cognitive, and emotional domains that occur during adolescence.

✵ 4.5 Discuss the concept of lifespan development and adulthood.

In a research study in the 1960s, preschool children in Palo Alto, California, were first asked to select what they would like as a treat. There were a number of choices available including cookies, little pretzels, mints, and marshmallows. The children were then given a choice: The choice was, “Would you like your treat now or if you wait, you can have more of what you like.” That is, eat the treat now or have two treats later. One girl, Amy, chose marshmallows. She sat alone at a table with the single marshmallow on it that she could have immediately. Also on the table were two marshmallows, which she could have if she waited. In some cases she would have to wait alone for up to 20 minutes. Also on the table was a bell that she could use to call the researcher. Then she could say, “I want to eat the single treat now.” Otherwise, she must wait for the researcher to return. Different children took various approaches to pass the time and not ring the bell.

Although this was initially a test of delay of gratification, the follow-up results showed differences that most people would not have imagined. For example, the longer a child waited at age 4 or 5, the higher his or her SAT scores were in adolescence, more than ten years later. How can that be? Also, those who waited longer rated their social and cognitive skills as better in adolescence. Just waiting at age 4 is related to how you rate yourself some ten years later. Even more amazing is that more than 20 years later by age 27—32 years old, the children who waited were less obese and had a better sense of self-worth. They were also able to deal more effectively with stress and frustration. Finally, by midlife, there was a difference in brain-imaging patterns related to addiction and obesity in those who were able to delay gratification compared to those who were not. Did these kids learn to delay gratification? Was it inborn? How did it happen? Does it change as the child becomes older? Developmental psychologists seek to answer these types of questions, as you will see in this chapter.

Based on The marshmallow test by Walter Mischel (2014).

We are all children who grew up. We began as infants. Most of us had a family. Some of us had brothers and sisters. What factors do you think influenced your development? Parents often think they play the most important role in their child’s development. However, many of you would also include the role your friends play. You may also name teachers, youth group leaders, and others vital to your development. What would you see as the really critical factors? Was it a series of single events or a more continuous process? Part of what developmental psychologists seek to understand are the factors that influence development and the manner in which they do so.

How might we understand how Amy was willing to wait to eat the marshmallow that she wanted? Was she born with the ability to delay gratification? Did she learn it? Or, was it a combination of factors? Additional research showed that although Amy could wait at age 5, younger children would not be able to consider waiting as an alternative (see Mischel, 2014 for an overview). Also, later research has shown that if the mothers of the children did not complete college, then the relationship between delay and later achievement was not as strong as in the original study (Watts, Duncan, & Quan, 2018). It has also been suggested that the marshmallow test is influenced by social factors such as growing up in a supportive environment (Michaelson & Munakata, 2020). Further, in a replication in China, 3-and 4-year-olds were shown to wait the longest if they were told their teacher would find out how long they waited (Ma, Zeng, Xu, Compton, & Heyman, 2020).

Further, how could a simple activity at age 4 or 5 be related to future success? This is the type of question developmental psychologists seek to answer. Developmental psychology is the study of cognitive, emotional, and motor development of humans across their lifespan. As you will see in this chapter, brain development is also an important aspect of human development. As noted in the first chapters of this book, there are a number of levels ranging from genes to culture that play critical roles in shaping our behavior. We know many of these, although we probably have not thought about our own life in a systematic manner.

In studying development, we can look at what is going on at each age (or stage) of our life. As infants, we learn how to walk and talk and see the world. As children, we learn how to play and interact with others as well as develop cognitive skills. As adolescents, we become part of a social group as well as experience our sexuality. As young adults, we consider our alternatives and create a life for ourselves. Some of us will create families as well as pursue a profession. As we continue to age some of us experience children and then grandchildren. At some point we consider retirement and what this stage will require.

In this chapter, you will learn about the development process we are all a part of as humans. You will also become familiar with the questions needed to be answered at each of our ages. These questions can include the languages we speak, the way we move, how we feel, and how we play with others. Later we think about who we should marry, what profession we should pursue, and how do we give meaning to our life. These questions differ at each period of our lifespan. This is referred to as lifespan development. As we move through life, our brain changes, and some specific periods are more critical than others.

Physical Development

The development of all our lives began with two cells—a sperm and an egg. Not long after birth we all have 100 billion neurons—the same as you have today. However, by the age that you are today, your brain has increased in size and the connections you have between areas of the brain are much more complex. Your abilities have also increased. You have learned how to speak and understand others. You understand social relations and the intentions of others. You can think logically and solve problems. You understand emotions in yourself and others. You have motor skills and can play games and perform various acts. Although education played an important role, many of these skills developed outside of formal education as you interacted with your environment, including your friends and culture. Let us now turn to the period before birth.

Prenatal Development

There are two critical periods in terms of brain development over one’s life. The first occurs in the womb, and the second is during adolescence (Váša et al., 2020). Although most of us understand that the brain develops when we are in the womb, adolescence is not usually considered. As you will see later in the chapter, your brain creates new patterns of organization during adolescence. This means that all types of factors and experiences can have a greater impact during this period. It is also at this time that many mental disorders develop. However, that is getting ahead of our story. Let’s return to conception and birth.

Before a child is born, the brain has begun to form the connections necessary to perform basic sensory and motor functions (see Byrge, Sporns, & Smith, 2014; Konrad & Eickhoff, 2010 for overviews of connectivity in the brain). This process begins about two to three weeks after conception with the development of brain tissue. At about 18 days, the neural tube begins to form, which will become the brain and spinal cord. Following this, there are periods of cell division that actually produce more neurons than will be utilized.

During the period three to six months before birth, your brain created as many as 250,000 neurons every minute. Yes, it is 250,000 per minute! Approximately half of all created neurons will die in a programmed manner between about the sixth month in the womb and the second month after birth (see Markant & Thomas, 2013; Zelazo & Lee, 2010 for overviews). At this point, you will have about 86 billion neurons, the same as you have today.

During this period, neurons migrate to the correct place in the brain. Once the neurons arrive at this final position, they continue the growth and development of dendrites that connect to other neurons. However, the number of connections between the neurons are much fewer at birth as compared to the brain of an adult human. At birth the brain is about one-third the size of an adult brain. By one year of age, your brain is about 60% the size of your adult brain and about 90% of adult weight by age 5. It takes until age 16 for the brain to reach its adult weight.

After the development of movement and vision, the brain develops from back to front. The last area to develop is the frontal lobes, which continue to develop into early adulthood. Overall, early environmental experiences have been shown to influence brain development, neurotransmitter functioning, and neuroendocrine function, which in turn can influence different types of behaviors (Burnette & Cicchetti, 2012).

Teratogens Can Change Brain Development

Given the fact that the brain grows so quickly prior to birth, a number of factors can influence this development in both positive and negative ways. Sufficient nutrients and vitamins can help the fetus develop, whereas their lack can negatively influence its development. Other substances such as alcohol, drugs, and lead as well as bacteria, viruses, and extreme temperatures can have terrible consequences on the fetus. These agents are referred to as teratogens. The word teratogen comes from the Greek word meaning monster.

Depending on the substance taken by the mother and the length of time and amount consumed, teratogens can influence physical development as well as behavioral, cognitive, and emotional development. One aspect of this influence is through a disruption in connections formed in the brain (van den Heuvel & Thomason, 2016). There are also individual differences in how teratogens influence development, and these can be related to genetic makeup (Cassina, Salviati, Di Gianantonio, & Clementi, 2016).

One well-studied disorder related to the teratogen of alcohol is fetal alcohol syndrome (FAS) (Carter & Cunniff, 2016). Actually, there are a number of conditions referred to as fetal alcohol spectrum disorders that occur when the mother drank alcohol during pregnancy. According to the US Centers for Disease Control and Prevention (CDC) (https://www.cdc.gov/ncbddd/fasd/facts.html), fetal alcohol disorders can be prevented if the mother does not drink alcohol during pregnancy. An infant with FAS can have any of the following: abnormal facial features, small head size, shorter-than-average height, low body weight, poor coordination, hyperactive behavior, difficulty with attention, poor memory, difficulty in school (especially with math), learning disabilities, speech and language delays, intellectual disability or low IQ, poor reasoning and judgment skills, sleep and sucking problems as a baby, vision or hearing problems, and problems with the heart, kidneys, or bones. The more alcohol that a woman drinks during pregnancy, especially binge drinking, the more likely that her child will show signs of FAS during his or her lifetime. Although no one has established a safe level of drinking during pregnancy, recent research suggests drinking less than one drink a day may have minimal effects on the fetus (https://www.cdc.gov/ncbddd/fasd/alcohol-use.html). However, most physician groups still suggest having no alcohol during pregnancy. The same is also true for recreational drugs.

Brain Development

During gestation and the early years of life, the brain is establishing its cortical connections and growing neurons at an amazing rate. Within this period, the infant initially develops the ability to process sensory information, which forms the basis of language and cognitive skills. These skills develop in a particular order.

The first areas to develop in an infant are related to movement and vision. There is actually a close connection between movement and the development of visual functions. In looking at the average motor skills developed during the first 16 months of life, consider how each of these new motor skills gives the infant a new perspective and experience of his or her world. These experiences change the connections and networks of the brain. For example, Joe Campos and his colleagues have shown that infants do not show fear of heights until they are able to crawl (Campos, Bertenthal, & Kermoian, 1992).

In this sense, the fear of heights emerges as a complex interaction involving the visual system and the motor system, as well as the feedback and experience that the infant receives as he or she begins to crawl. These factors are further influenced by such environmental factors as when the baby is born. For example, babies born in the winter crawl sooner than those born in the summer. Babies born in the winter need to develop before they can crawl. Thus, they would begin to learn to crawl during the summer, a time that parents are more likely to let them play on the floor.

As you would expect, the areas of the infant’s brain with increasing connections involve visual, auditory, and motor processing (Collin & van den Heuvel, 2013). As seen in Figure 4-1, language and spatial orientation, which involve the parietal areas, don’t fully develop until about puberty. Executive functions involving goals, reasoning as well as integration of information and social processes continue to develop until your 20s.

Figure 4-1 Timing of different types of learning in children. Sensory learning comes before language and more advanced cognitive functions such as reading, math, and understanding.

Source: Bardin (2012, p. 25).

If you were to use brain imaging such as MRI to look at your brain today, you would see less gray matter than you had as a child. This is because of an increase of white matter connections that increase the speed of processing throughout the brain. Neurons surrounded by white matter (myelin) transmit signals at 50 to 100 times faster than those that are unmyelinated. Figure 4-2 shows the decrease in gray matter volume from age 5 to age 20.

Figure 4-2 Changes in gray matter volume in the brains of those age 5 to age 20. Red color shows the highest gray matter volume and violet the lowest. As a person matures, the brain forms more connections with myelin sheaths (white matter) and thus reduces the gray matter measurements in the brain.

Source: Dennis and Thompson (2013).

Brain connections remain stable until about 12 years of age. During adolescence there is another critical period when the brain begins to rewire itself in a different manner (Váša et al., 2020). It is suggested that the adolescent brain should not be seen as either an old child brain or an underdeveloped adult brain (Giedd, 2015). Rather, the adolescent brain is unique in its ability to respond to the environment by modifying its network connections.

If we were to examine these connections between the ages of 12 and 30 years, we would see an increase in the connections that neurons make with one another (Dennis & Thompson, 2013). In Figure 4-3 the size of the node (green balls) reflects the number of connections and the thickness of the line reflects the strength of the connection. Thus, it is not the growth of brain areas that takes place in adolescence, but the connections these areas have with one another that increases communication between different areas in the brain.

Figure 4-3 Increasing connections in the brain from age 12 to 30. Bigger green circles show more connections. Thicker black lines show stronger connections.

Source: Giedd (2015, p. 35).

These cortical changes particularly involve such higher cognitive functions as reasoning, interpersonal interactions, cognitive control of emotions, risk-versus-reward appraisal, and motivation (Paus, Keshavan, & Ciedd, 2008). These changes are usually positive; however, a disruption can lead to problems. External or internal events, including genetic processes, can happen that may lead to physical or mental disorders. External events can include the use of drugs during adolescence, which can interfere with normal cortical development. The need for sleep is also critical for the adolescent brain during this period of cortical changes (Galván, 2020).

In terms of brain development, developmental psychologists consider the question of which of our psychological processes reflect more stable or invariant processes and which are less fixed and thus open to modification. The term that is often used to describe conditions in which processes are open to modification is referred to as plasticity. As you will see later in the chapter, in terms of development, a variety of studies have shown that both human and other primate infants who are initially deprived of social and emotional stimulation show later difficulties in these areas. However, some of these difficulties can be reversed if the infants are placed in a more caring and stimulating environment. Thus, humans and other organisms possess mechanisms that allow for plasticity in developmental processes.

Although plasticity exists, there are also critical or sensitive periods during which certain types of experiences must be present for successful functioning. One is with language. As you will learn in the chapter on language, infants by the sixth month of life are able to distinguish any sound (phoneme) in any language on earth. By 12 months of age, infants have more difficulty making these same distinctions in languages that are not their own (Kuhl, 2004, 2010). As an adult you can learn other languages, but you no longer can sound like a native speaker. As you will also see in this present chapter, psychologists have sought to understand the role of sensitive periods in a number of areas of human functions. In fact, at different periods of our development, it is as if our brains expect to receive a certain type of experience.

It is important to understand that a critical or sensitive period represents a close connection between our brain and our environment (Bardin, 2012). For example, when mice after birth first open their eyes, a protein called Otx2 is created in the retina and transported through the optic nerve to the area of the brain related to vision—the visual cortex (Sugiyama, Prochiantz, & Hensch, 2009). This causes cells in the visual cortex to start the process of establishing the critical pathways needed for vision. If the mice are raised in the dark, this entire process does not take place. In human children born with cataracts, three-dimensional vision does not develop. However, not every impairment is permanent. New research is beginning to study whether sensory processes that did not develop in the normal critical period could be improved through using drugs to reopen critical period mechanisms in the brain.

Overall, human infants display an amazing ability to develop brain connections that relate to a number of skills. As you will see, following birth, human infants are able to form connections with their caregivers and maintain a close connection with others. They learn language quickly. They know how to understand nonverbal expressions, and later be part of a larger social community. Every infant learns to talk and walk and express emotions.

Darwin suggested that the infant possesses intrinsic motivation. That is to say, the infant and then the child is a curious and interested explorer of the world rather than a passive recipient of environmental influences. We now know that infants actually seek new information on a variety of levels, including motor, emotional, and cognitive responses. He or she feels happy when solving a problem or learning something new, which in turn allows the infant to have a close relationship with its environment as it has new experiences.

Sensory Development

Psychologists often discuss development in terms of human processes. As such, development is considered in terms of motor development, cognitive development, language development, social development, emotional development, and so on (see Table 4-1). However, if you watch infants through their first years of life, you will see that there is a complex interaction involving all of these systems. Parents emotionally encourage their child when he or she stands or walks. There is a complex interaction with parents as the child begins toilet training. Part of the problem is that the muscles involved do not give the same feedback to the child as that experienced in other types of motor learning. Other individuals also influence development. With brothers and sisters as well as with day care providers, there are social and emotional interactions that take place on a number of levels. All of these experiences help create the richness seen in each individual’s development.

Not only does the infant find himself or herself in a particular environment, but, like a scientist or explorer, the infant wants to know what is there. You may wonder how psychologists can know this in an infant who cannot use language. There are a number of methods. Infants like adults show a change in heart rate when they find something interesting. Infants also suck a pacifier differently when they are engaged with what they see. Further, when infants see something they did not expect, they show a particular facial expression or even cry.

Each of these behaviors can be recorded and used in research. For example, when mothers read Dr. Seuss’s The Cat in the Hat to their fetuses once a day during the last six weeks of pregnancy, newborns showed a familiarity to the story that they did not show to other stories (DeCasper & Spence, 1986). How did the researchers know this? They determined it through the patterns of pacifier sucking. A follow-up study also showed heart rate changes to rhymes their mothers had recited during her late pregnancy compared to other rhymes (DeCasper, Lecanuet, Busnel, Granier-Deferre, & Maugeais, 1994).

Human newborns show the ability to make a variety of sensory differentiations (Rakison, 2005). For example, they prefer the taste and smell of sweet nourishment and can differentiate a variety of tastes. Newborns can identify—and prefer—the scent of their mother to the scent of a stranger. They can also recognize their mother’s voice, which they prefer.

In terms of visual perception, infants lack the ability to see detail (referred to as visual acuity) at birth. By age six months, they see almost as clearly as adults. It is at this age that the infants can connect the emotional responses seen in the face with the voice. Not surprisingly, infants prefer happy faces to angry or fearful ones.

Even with less acuity, newborns prefer more face-like images than those that have the same features but in different places (shown in Figure 4-4). Newborn infants from 1 to 3 days old also look longer at a right-side up face as opposed to an upside-down face (see Figure 4-5). Further, 1-month-old infants prefer looking at a human face as opposed to a monkey face (Sanefuji, Wada, Yamamoto, Mohri, & Taniike, 2014). This was true irrespective of the race of the person’s face. Even more surprising, with new technology that allows images to be projected through the uterine wall, a third trimester human fetus shows preferences to stimuli such as a face rather than an upside-down version of the same stimuli (Reid, Dunn, Young, Amu, Donovan, & Reissland, 2017).

Figure 4-4 Infants prefer more human-looking faces. The left face on top (54 seconds) versus top right (38 seconds), and the right face on bottom (41 seconds) versus left face (35 seconds).

Source: Turati, Simion, Milani, and Umiltà (2002).

Figure 4-5 Total fixation time for each face seen by newborn infants. They look more at the upright face as opposed to the upside-down face.

Source: Cassia, Turati, and Simion (2004, p. 381).

Since these studies have been carried out in laboratories around the world with different ethnic groups, it is assumed that this is a universal characteristic of all human infants. Overall, research suggests that newborns come into the world with mechanisms that predispose them to look at faces. Human newborns also respond to motion and are able to track moving objects. This, of course, is an evolved ability seen across a variety of species that would help track predators and thus increase an organism’s chance of survival.

Learning From the Environment

Not only do human infants actively search their environment, they have expectations of what should happen next. How do we know this? We know this by what an infant focuses on and how long they pay attention to a particular action. Like adults, when infants see the same action over and over again, they stop paying attention. This is technically referred to as habituation.

Habituation can happen in any sensory modality. If you move into an apartment near a bell tower or train track or airline flight path, you initially notice each time you hear the sound. After a while, you don’t even notice the event. Not only do we expect sensory events, but also cognitive and psychological events. We, as well as infants, pay particular attention to those events we do not predict. We will even show surprise when the event is totally beyond our expectation.

Renée Baillargeon and her colleagues used infants’ reactions to study their sensory, cognitive, and psychological reasoning (Baillargeon, 2004; Luo & Baillargeon, 2005; Baillargeon, Scott, & He, 2010). In a number of studies over 20 years, we now know that even infants as young as 2.5 months possess expectations about physical events, and that these expectations undergo significant development during the first year of life.

One research design is to show the infant a toy doll. Two structures would then come down—one of which would hide the doll. If the doll were to move from one side to the other, it would be seen in the opening between the two sides. However, if the doll appeared on the other side when the screen was pulled up, the infant would look longer than when it would appear on the expected side. This suggested that young infants have an expectation of how the world works.

Not only do infants have expectations, but they also act as “little scientists” and try to test out their ideas. When their expectations are not met, they try to learn from what they experience. Aimee Stahl and Lisa Feigenson showed 110 infants situations that were consistent with what would be expected and situations that were not (see Figure 4-6). To strengthen their research, they included a number of control conditions to rule out alternative explanations (Stahl & Feigenson, 2015).

Figure 4-6 If the infant sees the car violating the law of gravity, he or she will drop it on their highchair. If the infant sees the car appear to go through the barrier, the infant will try to push it through their tray.

Source: Schulz (2015) based on Stahl and Feigenson (2015).

The main idea of the study was that infants treat unexpected events differently and use these events to learn new things about the world. The conditions compared an expected condition with an unexpected one. In the expected case, a toy such as a car or ball is stopped by a barrier. In the unexpected case, the toy goes through the barrier as if by magic. When the 11-month-old infant is given the toy that went through the barrier, he or she will take the toy and bang it on the highchair tray as if to test whether it will go through the tray as it did with the barrier.

In another condition, the toy is pushed past the end of a box. In the expected condition, the toy falls to the floor. In the unexpected condition, the toy continues as if the box were still below it. When given the toy after this, the infant drops it as if to see whether it will fall. It is as if the infant is trying to make the toy perform the same way as what they observed. However, the infants did not seek to learn from toys that did not violate their expectations. They just treated these toys as they always had (see movies of the different research conditions in http://www.npr.org/blogs/ed/2015/04/02/396812961/why-babies-love-and-learn-from-magic-tricks and the supplemental information published online at http://www.sciencemag.org/content/348/6230/91/suppl/DC1).

This study shows us that infants already have expectations about the world. Not only do they have expectations, but if their expectations are violated, they try to learn the new information. That is, they drop the toy that did not fall or bang the toy on their tray to see if it will indeed go through as it did with the barrier. In this sense, infants are like scientists. That is, when confronted with unexpected results, they explore and seek to gain new information and create new hypotheses about how the world works.

As psychologists we tend to focus on the cognitive and emotional levels, but we must realize that the infant’s nervous system is constantly asking questions concerning what it needs next on the basic levels as well. We know, for example, that if children lack a certain substance in their diet, they will modify their diet, if allowed, to increase those foods in which they are deficient (Davis, 1939). Other species also show similar food preferences for balancing their internal processes (Rozin & Schull, 1988). Overall, this suggests that an infant comes into the world with a series of procedures ready to be exploited for his or her own benefit.

Motor Development

In 1877 Charles Darwin published a description of an infant developing (Darwin, 1877, Mind). He began by describing the reflex actions he observed in the infant, such as yawning, stretching, sucking, and screaming. Darwin touched the bottom of the infant’s foot and it pulled away. On the ninth day of the infant’s life, Darwin reported that the infant focused on a candle. Darwin also noted when different emotions first appeared. This was one of the early case studies that informed what was to become developmental psychology. By the way, this infant was Darwin’s own son.

As Darwin noted with his own son, humans come into this world with a number of reflexes. One of these is the grasping reflex in which the infant will grab your finger. Since infants can actually hold their own weight, many researchers see this as part of our evolutionary history. If you take your finger and place it near an infant’s mouth, he or she will turn toward it and open its mouth. This is referred to as the rooting reflex. Infants will also show a sucking reflex if something touches their lips. This can also be their own thumb. Sucking one’s thumb and moving arms and legs is also the beginning of gaining a sense of one’s body and where it exists in space. You actually need to learn that you have arms and legs and that you can control them.

Motor development in infants proceeds in two directions. The first is from head to toe, and the second is from the midline of the body to the periphery. At about 2 months of age, the infant develops the muscles necessary for raising his or her head. About a month later, the infant develops the muscles of the torso necessary to roll over and sit in a highchair. During the next six months, the infant can begin to crawl. At the first year of age, infants can begin to stand while holding on to a low table and take steps on their own. Likewise, development goes from the midline in which infants can move their arms and legs before they can actually use their hands to purposely grab an object. Figure 4-7 shows the motor milestones that an infant passes through. Interestingly, infants who are born blind go through motor milestones in a similar order to sighted infants. However, blind babies reach these milestones anywhere from a few weeks to a few months later (Adelson & Fraiberg, 1974).

Figure 4-7 Motor skills developed during the first 16 months of life.

Humans also retain previous physiological structures from our evolutionary history that are neither adaptive nor functional. These are called vestigial structures. For example, human babies can grasp and hold their own weight. Other primates, of course, need to hold on to their mother as she moves through the trees. Some people can wiggle their ears. This probably remained from other mammals that make ear movements to localize sounds.

Myrtle McGraw was a developmental psychologist in the 1930s who was interested in the motor development of infants. She was the first to ask if there was a swimming reflex in 2-to 4-month-old infants. Fortunately for the infants, there was. Infants show a swimming reflex until about 6 months of age; after that point, it disappears.

One of her research projects was to work with Johnny and Jimmy who were twins (McGraw, 1935). She taught one of the twins a number of motor skills including roller skating, climbing, and swimming. The other twin was not taught these skills until 22 months of age. Her procedure was to watch the first twin and as soon as McGraw saw a motor skill begin to be expressed, she would then start to develop it. One general conclusion from this work is that infants are able to perform a variety of motor tasks but there is no advantage to teaching these tasks earlier. To learn a new motor task still requires a sequence of steps.

Esther Thelen also watched infants as they learned motor skills such as walking. However, she sought to integrate an understanding of motor movement with advances in the neurosciences, biomechanics, and the study of perception and action. Her initial work was summarized in her 1995 book and referred to as dynamic system theory (Thelen, 1995; Smith & Thelen, 2003).

Figure 4-8 Infant showing swimming reflex.

Part of her work is based on the Russian movement physiologist Nikolai Bernstein who suggested that there is an important cognitive component in our actions. That is, we perform actions differently in terms of what we expect to happen. We must also put together a number of possible body movements. If you hold a 1-month-old infant under the arms on a moving treadmill, he or she will show stepping movement similar to an adult walking. However, the infant will not show this movement alone until they are 1 year old. In learning movements we are also faced with physical constraints such as gravity. The emphasis for the dynamic system approach is to ask how all of our different body parts work together to produce stability and change. One conclusion is that the general milestones as shown in Figure 4-7 reflect the average age norm, but not the only pattern of motor development. Table 4-1 shows the milestone in four different areas from 15 months to 5 years.

CONCEPT CHECK

1. What are the two critical periods in terms of brain development over one’s life, and what happens that is so critical in each of these periods?

2. On the face of it, developing a fear of heights seems like a simple process. What are the critical factors in the complex interactions that actually take place?

3. Studies have shown that “when infants see something that does not behave in an expected way, they pay more attention to it.” What is the evolutionary value of this fact for humans?

4. Define the following concepts in terms of psychological processing and give an example of each:

a. plasticity

b. critical or sensitive periods.

5. Infants can’t fill out a questionnaire or press a button in an experiment. What are some of the methods researchers have used to assess an infant’s “answer” in experimental situations?

6. How did the dynamic system theory of Esther Thelen and Nikolai Bernstein change and expand the traditional understanding of motor development during the first six years?

Cognitive Development

Not everyone at the beginning of the 20th century agreed with the view of infants as scientists with expectations. As noted earlier, one of the influences in psychology in the early part of the 20th century came from John Watson and behaviorism (Watson, 1913, 1924). Watson suggested that the environment was the only significant factor needed to understand human development. In fact, he said:

Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I’ll guarantee to take any one at random and train him to become any type of specialist I might select — doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors. I am going beyond my facts and I admit it, but so have the advocates of the contrary and they have been doing it for many thousands of years.

(Watson, 1930: 82)

Heredity and instinctual processes were dismissed and largely ignored by Watson. In fact, Watson suggested only three instincts were present at birth: love, fear, and rage. Thus, neither intelligence nor special abilities were seen to be the product of genetic influences. He further suggested that parents were too sentimental to bring up their children properly. Although Watson influenced a number of psychologists during the first half of the 20th century, his ideas have not been supported by critical research.

Other researchers at that time sought to articulate patterns of development across motor, emotional, cognitive, and social domains. Jean Piaget emphasized the interaction with the physical environment and the manner in which a child’s mind develops. Lev Vygotsky stressed the social and cultural environment and how this influences development. Let us begin with Piaget.

Piaget and Stages of Development

Jean Piaget studied the cognitive development of children. In fact, Piaget is considered to have created the study of cognitive development. Cognitive development refers to the way we reason and use language, as well as traditional intellectual abilities such as memory and problem solving. Piaget’s work was mainly based on the observation of children at different ages. Piaget initially studied with Alfred Binet in Paris in the early 1900s and worked on the first intelligence tests. Alfred Binet, who you will learn about in the chapter on intelligence, was one of the first to study differing abilities of children who were the same age. One thing Piaget found interesting was that children of the same age tended to make the same mistakes compared to younger or older children. The children also differed in systematic ways from children both older and younger. Piaget developed his ideas by giving children problems to solve and watching the children attempt to solve them.

During this period, it was not uncommon for the average person to see a child as a small adult. What Piaget did was to show that a child understands his or her world differently at different points in life. His theoretical position suggests that a child moves through a series of stages and that these influence how he or she sees the world. The child learns or constructs knowledge of the world through observation and interaction. In this sense, a child is like a scientist who has ideas and seeks to test them.

Piaget introduced the term schema, which refers to how the child sees the world. Although schemas influence our actions, it typically works outside of our awareness. One important part of Piaget’s contribution was the idea that a child has a different schema or set of assumptions at different periods of his or her life. These schemas can be changed as the child interacts with the world and takes in new information.

The process by which schemas are changed involves two processes. The first is assimilation. Assimilation is the process by which new experiences are made part of existing schemas. Of course, not every experience becomes part of existing schemas. The child must first be ready for it. A child, for example, may learn to view fairy tales on a tablet computer such as an iPad and move his or her finger to change the page. If someone else, such as a grandparent, brings a book with the same fairy tale, the child may attempt to also use his finger to change the page. In this way the child tries to use an existing schema such as moving his finger in the new situation of a physical (not electronic!) book.

The child then must use the second process by which schemas are changed—accommodation. Accommodation is the process by which existing schemas are modified or new ones created. In the fairy tale example, the child begins to understand that there is another category of media that contains fairy tales—physical books—and physical books work differently than e-books on a tablet computer.

Piaget saw children as not just expressing random ideas. Rather, they are attempting to make sense of the world through a set of rules they have acquired. Through his observations of how children solve problems as well as the mistakes they make, Piaget suggested there were four periods or stages of development. These four stages are (1) sensorimotor, (2) preoperational, (3) concrete operations, and (4) formal operations. Further, these stages were seen to correspond with particular ages of the child.

The sensorimotor stage is characterized by the use of motor actions and the senses. The actions you see in an infant are not random but are his or her attempts to understand the environment through sensory and motor processes. This stage lasts from birth to 2 years of life. Looking, touching, and grasping give the infant a sense of her world. Give an infant an object and she will put the object in her month.

Initially, the child understands something exists only while that object is experienced. “Out of sight, out of mind” is the experience of the infant. Parents use this as they play “peek-a-boo” with their infant. Near the end of this stage, infants begin to understand that an object still exists even if it is covered with a cloth or placed in a drawer. This is the beginning of what is referred to as object permanence. We now know that object permanence develops as memory develops (Diamond, 1985).

The preoperational stage shows the beginning of symbolic thought. The thought is symbolic in that it can transcend the objects at hand. A child may take a stick and treat it like a sword, guitar, or rake. Pretend play is an important activity, especially in the early part of this stage. Parents often like playing with their children in terms of these pretend games and enjoy their magical ways of thinking.

The preoperational stage lasts from 2 to 7 years of age. Although children in this stage can use images of doing something before actually performing the act, they have difficulty doing the reverse. That is, they are not able to logically determine what would happen if they did not do the act. Also, their perspective is based on perceptions. This is demonstrated by the liquid conservation task, as shown in Figure 4-9.

Figure 4-9 Liquid conservation task. The liquid is poured from one of two equal-sized containers into one of a different shape (b). The child is then asked if the liquids in c are equal.

In this task, you first show the child the two containers that have an equal amount of liquid, as shown in a. You then pour the liquid from one of those containers into a tall container, as shown in b. You then show the child the two containers shown in c and ask which has the most liquid. Children in the pre-operational stage will say that the taller container in c contains more liquid even though they saw it being poured.

Conservation is seen not only with liquids but also with mass. Take two equal balls of clay and roll each out into a snake-like shape. If one is longer than the other, the child will choose that one as the one that contains more clay. Likewise, take candies such as M&Ms and place the same number in each of two rows—six candies, for example. Then you take one of the rows and spread it out so that there is more space between the individual candies. Again, the child will say the longer row contains more. This will happen even if you ask the child to count the number of candies in each row.

The third stage identified by Piaget is concrete operations. This stage begins at about 6 or 7 years of age and lasts until the child is about 11 years old. Children in this stage can move their thinking beyond themselves and deal with the nature of concrete objects. Children in elementary school, for example, can perform mathematical operations in terms of adding, subtracting, multiplying, and dividing. They can solve problems based on the example in front of them. However, Piaget suggested that children at this stage could not perform the abstract problems as seen in algebra or computer programming where one variable represents a general class in the abstract.

With the schema to perform abstract operations comes the fourth stage—formal operations. This stage begins in adolescents at about 12 years of age. Adolescents can think in abstract terms and solve hypothetical problems. They find it possible to talk about ideas like world peace or justice. They also can imagine worlds that do not exist. They can create theories of how the world should be different, especially how their parents should act. In their school work and other projects, they are able to form hypotheses and consider ways of testing them.

Piaget’s ideas played an important role in developmental psychology. His work influenced psychological research as well as educational perspectives. In particular, educators today seek to consider what students of a certain age are able to understand and how they will receive the information that is being taught. There are also more interactive types of problems aimed at students’ stage of development. Of course, since Piaget began his observations in the 1930s, a number of research studies have better defined infant and childhood development. We now know that different abilities and ways of thinking, feeling, and doing develop at different rates. We also know that given the correct situation, children may show abilities earlier than suggested by Piaget. There have also been scientific explorations beyond cognitive development to examine social and emotional development. This has led us to think more about the roles of culture, parents, and friends in a person’s development.

Vygotsky and the Sociocultural Perspective

It was the Russian psychologist Lev Vygotsky who offered a sociocultural perspective to cognitive development. Vygotsky was born in the same year as Piaget, 1896. Both saw the child’s interactions with his or her environment as critical to development. However, whereas Piaget emphasized the interaction with the physical environment, Vygotsky stressed the social and cultural environment. It is the child’s interactions with others that largely shape the child’s development. From our culture we learn a language. From our culture we are also given stories and histories that influence how we view ourselves and others.

Learning facilities differ around the world. Some cultures offer a more technological approach with computers and other devices. Other cultures emphasize a more literary and oral tradition with the learning of critical books. These are referred to as tools of intellectual adaptation. Of course, the language that a culture uses is one of the important tools. It is through language with his or her parents and others in the culture that the young child comes to be a social being and understand the world. Further, unlike Piaget, Vygotsky saw an important relationship between language and thought. Thought for Vygotsky is internal speech.

Children learn from those around them. As such, children can solve more difficult problems with an adult’s help. Less difficult problems they can solve on their own. In between these two situations was an area Vygotsky referred to as the zone of proximal development. This zone is the difference between what the child can do independently and what he or she can do with the help of another who is more advanced. The zone of proximal development represents a concept for developmental psychologists that points to how a child can learn from more experienced others. As such, this concept is especially valuable to teachers in considering what skills should be taught next.

In summary, the theories of Piaget and Vygotsky were broad-based theories initially based on observation and theory. By the middle of the 20th century, there was a movement to test development patterns with research. There was also a tendency to focus on particular development processes. One important process that has been extensively researched is memory.

Memory

Developmentally, human infants have an amazing capacity for remembering spoken words and songs as well as faces. However, most of us remember little of our life until we are about 3 or 4 years of age. One influential idea is that we need certain brain networks to develop before we can recall events from our lives. As you will see in the chapter on memory, this is referred to as autobiographical memory. Specifically, it is suggested that memory and cognitive systems are organized around infants’ experience of events, including their interactions with others.

Social relations play a special role in the life of humans. Flavell (2000) has suggested four ways in which the early predisposition and abilities of infants involve other humans. First, human infants find human faces, voices, and movements highly interesting. Second, infants can perceptually analyze and discriminate human stimuli. Third, infants seek to attend to and interact with other humans. And fourth, infants respond differently to humans than they do to objects. Other humans are special to humans.

Infants are capable of learning new information that involves different types of memory processes. For example, if an infant has learned to solve a simple puzzle, he or she shows improvement when presented with the same puzzle a second time. What happens when you begin a nursery rhyme with an infant? The infant says the next word, which shows the early development of cognitive memory. By age 2, toddlers show the ability to use memory processes to discuss events in their lives. As such they can begin simple narratives. This is illustrated by saying to a 2-year-old, “Tell Mommy what you just did” and she says, “I just threw the ball.” By age 3 to 5, most children can describe events and display memory of events. True memory of events is more than just recalling your participation in a particular event, it also includes the ability to do this without any situational cues for its recall in the present. That is to say, you can recall at will particular events that happened in your life at almost any of your previous ages. This, of course, requires that you have a sense of time, that is, past, present, and future. Like language, some researchers view memory of events as unique to humans. However, it should be noted that some cultures do not use the same sense of time in their language as do Western cultures. It should also be noted that just playing music to your baby does not necessarily make him or her a genius, as described in the box: Myths and Misconceptions—Mozart Effect.

Myths and Misconceptions—Mozart Effect

All parents want to help their child develop in superior ways. The media has articles on “ten ways to make your baby smart” or “how to stimulate your baby.” One web-site has an article on “15 signs you will raise a genius.” Thus, when you hear about a new technique, you consider trying it out. Yet, not every suggestion has been tested scientifically.

One that was tested is referred to as the Mozart effect. In 1993, a study was conducted with college students that reported that listening to music by Mozart for 10 minutes improved performance on three spatial tasks commonly used in intelligence tests (Rauscher, Shaw, & Ky, 1993). Listening to music was compared with listening to a relaxation tape or silence. The Mozart effect was shown to last for a short time, less than 15 minutes.

Although the study was conducted with college students, the idea was presented in the media that playing music by Mozart to your baby would improve his or her intelligence. It sounded reasonable to many since Mozart was a genius and created complex musical patterns. Even the Governor of Georgia, Zell Miller, suggested that the state should send every newborn a CD of classical music. Toy companies began to sell special genius CDs. Somehow, the music was supposed to change and improve the baby’s brain.

The popularity of the Mozart effect brought forth a number of research studies seeking to test the idea. Christopher Chabris reviewed 16 of these studies, principally those whose subjects were young adults (Chabris, 1999). Additionally, he used a technique referred to as meta-analysis that statistically combined the results of all the studies that included 714 participants. Chabris found that the so-called Mozart effect showed a change of only a few IQ points rather than the eight or nine originally suggested. Further, listening to a Stephen King story or popular music also increased performance. However, this appeared to be true only for those who enjoyed what they had heard.

Chabris suggested that since spatial tasks rely on the right hemisphere of the human brain, other processes such as enjoyment may also prime this region of the brain. If the right hemisphere was activated by a previous task, then doing a spatial task would not require as much cognitive effort. It would also explain why the original effect was short-lived. Other studies with school-age children have shown that listening to Mozart is not unique in promoting this performance. Listening to popular dance music led to the same changes in spatial performance as Mozart (McKelvie & Low, 2002).

What can we learn from the Mozart effect? The first is that we as human beings are always looking for easy ways to improve ourselves and our children. Of course as you learned previously, you can change your brain by learning to play a musical instrument as a child, but that takes effort and requires a long-term commitment. Another study showed that teaching children to play the piano also improved performance on a spatial task (Rausher, Shaw, Levine, Wright, Dennis, & Newcombe, 1997). Second, the media often presents the results of a scientific study in ways that go beyond the data presented. The authors of the original Mozart effect study, for example, never suggested that listening to music could change your brain or IQ in a long-term manner. And third, it is critical to replicate the study and conduct additional studies in order to understand the conditions under which the effects take place and determine the limits to the effect. By the way, if you go to amazon.com today you will discover a large number of books available to help you heal your body, strengthen your mind, and unlock your creative spirit using the Mozart effect. Perhaps, once the public has accepted a myth, they have a hard time giving it up.

Thought Question: What advertisements have you seen on TV or online that promise miraculous results just by “reading this book,” “using this piece of exercise equipment,” or “taking this pill”? How could you go about researching the scientific evidence behind the claim?

Temperament

We all come into the world with bodily emotional responses all our own. Some infants are very active and others somewhat quiet. Interestingly enough, the emotional responses seen early in one’s life remain fairly stable. This constellation of emotional and behavioral responses is referred to as temperament. Some infants seem happy all the time while others look to outsiders as if they are fearful or anxious. Although temperament has been described for thousands of years, it was reintroduced to the study of infants during the 1960s and 1970s (Chess & Thomas, 1977).

Longitudinal studies of temperament were conducted by Jerome Kagan and his colleagues at Harvard University (see Kagan, 2003 for an overview). These researchers began to follow different groups of infants as they grew. They sought to study the stability of their temperament in terms of behavioral, emotional, and physiological measures. Kagan and his colleagues classified infants in terms of reactivity. If the infants are exposed to an unfamiliar event such as a toy that makes noise and moves, about 20% of the 4-month-old infants will show distress and vigorous motor activity. These same high-reactive infants will be shy, timid, and fearful in response to unfamiliar events in their second year of life. One-third of these high-reactive children become very fearful and are referred to as inhibited by Kagan. About 40% of the infants Kagan and his colleagues studied showed low levels of reactivity to unfamiliar events. This was also seen during the second year of life as these children appeared sociable and less fearful in unfamiliar situations. One-third of the low-reactive infants show almost no fear and are referred to as uninhibited. By age 11, more children who were high-reactive at an earlier age were now shy. On the other hand, more low-reactive children were sociable and emotionally spontaneous in unfamiliar situations. EEG differences were also seen at age 2 and age 11 between high-reactive and low-reactive children.

Temperament is seen as a broad set of emotional and behavioral reactions. Both genetic and environmental factors are seen to play a role. Later in the chapter on personality, you will see which cognitive and emotional responses in childhood remain consistent over the lifespan. Personality, as you will see later, is more of a way of valuing and processing one’s world, which shares some components with temperament.

CONCEPT CHECK

1. What did John Watson and those tied to the behaviorism perspective believe were the critical factors in explaining a child’s development? Which factors did they think were unimportant?

2. What did Jean Piaget mean by the term “schema”? How do the processes of assimilation and accommodation work together to change schemas during development?

3. Russian psychologist Lev Vygotsky offered a sociocultural perspective to cognitive development. What did he consider the critical factors in a child’s development? How did Vygotsky’s concepts of “tools of intellectual development” and “zone of proximal development” play a role in his theory of development?

4. Most of us remember little of our life until we are about 3 or 4 years of age, yet aspects of memory development are very active in infants and very young children. What evidence does this chapter present on early memory processes?

5. Well, it turns out we can’t improve our cognitive performance by listening to Mozart’s music, but what three things can we learn from the “Mozart effect”?

6. What have we learned from the research of Jerome Kagan and his colleagues on the development and stability of temperament during childhood?

Learning about Others and the World

As you have learned so far, infants are able to learn important aspects of motor and cognitive development. They are able to move through their world. They are also able to demonstrate an understanding of basic cognitive processes depending on their level of development. In this next section, you will be introduced to important aspects of social development. In particular, you will learn about how we learn by watching others, how we come to understand their actions and intentions, and how we make emotional and social connections with others, especially our caregivers. The section ends with a discussion of how parents interact with their children.

Mirror Neurons and Imitation Learning

How do you know what someone else is experiencing? What helps us feel empathy for that person? Most of us would answer that we know because it is an experience that has happened to us. While this is true, we now understand more about the mechanisms that allow this to happen. Let’s begin with a simple act.

What happens in your brain when you see someone wave or clap her hands? One intriguing answer to this question comes from research that suggests the neurons in your brain fire as if you had performed the same actions. These neurons are called mirror neurons. Mirror neurons were first discovered in monkeys. These neurons were shown to fire both when the monkey performs a particular action, as well as when it just observes another monkey, or even a human, perform that action.

These mirror neurons were first discovered in areas of the brain referred to as F5, which is a part of the premotor cortex. Some researchers suggest that this brain process may lie at the basis of imitation learning, as well as other human social phenomena, including language and empathy (Rizzolatti & Craighero, 2004; Sinigaglia & Rizzolatti, 2011). Imitation learning is seen in a number of species. You watch someone do something and then you copy it. Children may simply watch a video and then copy what they saw.

The basic idea for imitation learning is simple. Each time an individual sees an action done by another, the neurons that would be involved in that action are activated. This activation in brain circuits in turn creates a motor representation of the observed action. That is, we see an action and our brain considers how we might make it ourselves, although we don’t do this consciously. What this means is that our brain turns a visual image into a motor plan. A motor plan is nothing more than how we would perform an action.

This process can explain one aspect of how imitation learning can take place. That is, by seeing something, my brain also comes to know how I can do it. Since the same neurons fire in my brain as I watch another do a task, my brain is able to create an action plan when I wish to produce the motor response. Even more important for Rizzolatti and Fogassi (2014) is that such a network puts the organism at an advantage. The advantage is not only do I understand “what” others are doing, but also “why” they are doing it. I am able to make guesses at their motivation and their plan of action. Thus, by having my brain work similarly to another’s brain, then I have some understanding of what he or she is experiencing.

It has also been suggested that the mirror neurons not only lead to an understanding of another’s actions but also to empathy (see Iacoboni, 2009 for an overview). The basic idea is that through connections between the mirror neuron system and the limbic system, which is related to emotional processing, and the insula, which is related to a sense of self, it would be possible to recognize emotions and thus empathy. In a series of studies, it was shown that the more someone imitates your actions, the more you like that person and report that you care about them (Chartrand & Bargh 1999). Thus, imitation, liking, and caring go together. This in turn could be an important part of interpersonal relationships. Although most schools emphasize cognitive development, there are programs based on scientific principles that seek to integrate emotional development with other learning. One of these programs is described in the box: Applying Psychological Science—Early Intervention Programs—The PATHS Curriculum.

Applying Psychological Science—Early Intervention Programs—The PATHS Curriculum

Children come to school influenced by many different experiences. Some have had difficult families where the experience of anger was common. Some have had parents who were not available when needed. Some children lacked basic nutrition. This leaves an important challenge for school teachers to help children with the integration of cognitive, emotional, and motor tasks. As children mature, they begin to talk about their internal processes as well as those of others. Some children do this better than others. As many teachers will tell you, formal social and emotional education for preschool and elementary school students is often not available. Without these skills, children may show behavioral problems and aggressive behaviors. Various programs have been developed to increase social and emotional skills.

One program designed to help children form relationships and monitor their emotions and social needs as well as those of others is Promoting Alternative Thinking Strategies (PATHS). This program was developed by Mark Greenberg, a psychologist at Pennsylvania State University, and his colleagues. They have also tested their program in outcome studies (Greenberg 2018; Greenberg, & Lippoid, 2013; Mahoney et al., 2020). The PATHS curriculum was developed as a preventive program designed to give children more awareness of their own emotions and those of others. In addition, they are taught a way of solving problems from a cognitive perspective and preventing negative emotional and social outcomes. Overall, the children learn about self-control, understanding their emotions, self-esteem, relationships, and how to work with others.

Reviews of the literature have shown a relationship between a child’s emotional understanding and the ability to have positive social relationships. Additionally, the ability to inhibit one’s actions is associated with successful social and academic performance. In this view, emotional understanding is related to less acting out or negative internal attributions (Upshur, Wenz-Gross, & Reed, 2013).

Across the world, children may not have the family structure that supports problem solving and prosocial relationships. In these situations, programs that support the child being able to regulate emotions and solve day-to-day problems are critical. At this point, the PATHS curriculum has been studied in a number of developing and developed countries. Studies from both Germany and the Netherlands have shown positive effects of the training.

Head Start is the largest provider of early childhood education for disadvantaged children in the United States. One study followed children in Head Start using the PATHS curriculum (Domitrovich, Cortes, & Greenberg, 2007). The preschool children were randomly assigned to either the PATHS curriculum or a control situation on a classroom level. The children in different classrooms were matched so that similar characteristics were present in those children who received the PATHS curriculum and those who did not. The PATHS program was presented once a week for 30 weeks by the Head Start teachers who had been trained. The results suggest that after exposure to PATHS, intervention children had higher emotion knowledge skills and were rated by parents and teachers as more socially competent compared to peers. Further, teachers rated children who received the PATHS curriculum as less socially withdrawn at the end of the school year compared to controls.

An additional study examined 2,937 children over the first three years of elementary school (Conduct Problems Prevention Research Group, 2010). In those classrooms that received the PATHS curriculum, there was a reduction in aggression and an increase in prosocial behavior as reported by teachers. Peer reports also found a reduction in aggression, especially for boys. These researchers concluded that well-implemented multiyear social—emotional learning programs can have significant and meaningful preventive effects on the population-level rates of aggression, social competence, and academic engagement in the elementary school years. Overall, helping children become aware of the emotional and social responses of themselves and others as well as methods to reduce conflict is an important component of a child’s successful development.

Thought Question: When you were in elementary school, how were you helped to think about your emotions and solve interpersonal problems?

Theory of Mind

Before mirror neurons were discovered, a number of developmental psychologists studied the ways in which children understood the actions of others. Surprisingly, an important aspect of this work focused on animals. Theory of mind was initially researched by Premack and Woodruff in 1978 in relation to primates. As scientists have considered the differences between humans and other primates, the differentiation generally focuses on social aspects of human interaction (see Dunbar, 2003 for an overview). In particular, two important distinctions are the utilization of language and the ability of humans to infer another person’s mental state and intentions.

Theory of mind continues to be an important topic in developmental psychology. Included in theory of mind is the capacity to infer another person’s mental state from their behavior. Mental state can include purpose, intention, knowledge, belief, thinking, doubt, pretending, liking, and so forth. Some researchers have suggested that only humans possess this ability, which allows for sophisticated social interactions.

One experimental procedure for understanding theory of mind uses a cereal box. This technique is formally called the “false-belief” task. In this procedure, a cereal box, for example, is shown to the child. The child is then asked what is in the box. Of course, the child responds by naming the type of cereal, such as Cheerios. The experimenter then opens the box and shows the child it contains something else, such as ribbons. The child is then asked what another child out in the hall would think is in the box. Three-year-old children tend to respond “ribbons,” whereas four-year-olds would say “Cheerios.” Thus, the four-year-olds understand what others would believe, whereas three-year-olds would not. In the final part of the task, the experimenter asks the children what they initially thought was in the box. Four-year-olds say Cheerios, whereas three-year-olds say ribbons. When theory-of-mind type of tasks have been given around the world, it is observed that it develops at about the same time. Few three-year-olds correctly understand what another knows and few five-year-olds are incorrect in their ability to understand what another child would experience.

Theories of Attachment

In the course of development, there are a number of especially sensitive periods in which disruptions can lead to long-term effects. For example, what happens when events such as war or natural disasters interrupt the normal caregiving patterns? The British psychiatrist John Bowlby sought to determine what would happen if a young child had his or her physical needs such as food and housing satisfied, but did not experience a close emotional connection. His early work examined children who became orphans during World War II. They were physically cared for, but lacked the emotional attention given from a caregiver, such as a mother dealing with her own infant. His and later research has shown that these infants display patterns of interpersonal behaviors that have been associated with psychological problems. He referred to the infant—mother relationship as attachment.

John Bowlby developed a theoretical understanding of interpersonal relationships based on the interactions of a child with his or her parents. Of course, this type of bonding has great survival value for a human infant who cannot take care of him or herself. Along with a number of other instincts, such as the rooting reflex in which an infant begins sucking when the cheek or mouth are touched, attachment is seen as the basis of early emotional relationships between a mother and her child. It initially begins in terms of nursing as the mother and her child learn how to respond to each other. Both internal and external processes and their constant interplay lead to mother—infant bonding.

Bowlby considered the process of attachment as a social-emotional behavior equally as important as mating behavior and parental behavior. He saw attachment as a multifaceted process involving a variety of developmental mechanisms over the first year of life. For Bowlby, attachment was a process in which the mother was able to reduce fear by direct contact with the infant and provide support, called a secure base. This secure base would allow for later exploratory behaviors. Bowlby suggested that there were five universal attachment behaviors in human infants. These are sucking, clinging, crying, following, and smiling. Bowlby assumed that the relative immaturity of the human infant resulted in attachment being a slower process in humans than in other primates.

Specifically, the development of attachment takes place in four phases according to Bowlby. The first phase is preattachment and lasts from birth to 6 weeks of age. During this period, the infant produces such behaviors as crying. In turn, the caregiver comes and comforts the infant. The second phase is attachment in the making that lasts from about 6 weeks to 8 months. During this phase, infants smile, laugh, or babble in the presence of their caregivers. It is at this time that the infants begin to develop trust or the lack thereof. The third phase is clear-cutattachment. Beginning at about 8 months, this phase lasts until about 1 ½ years of age. Infants are happy to see their caregiver and show distress when left. The fourth phase is reciprocal relationships, which lasts from 1 ½ or 2 years on. This represents a more mutual relationship based on the infant’s abilities to use language and understand emotions.

Attachment in Primates

In a classic series of experiments in the 1950s, Harry Harlow initially examined the mechanisms of attachment with primates. At that time, there was a real debate between whether the infant’s response to its mother is learned, or whether certain inherent properties of the mother elicit infant attachment (Harlow, McGaugh, & Thompson, 1971). To better understand the nature of attachment in monkey infants, Harlow (1958) separated infant monkeys from their mothers after birth and placed them in isolated cages. In the cage were two surrogate mothers—one made of wire and the other made of terrycloth (see Figure 4-10). The wire surrogates had bare bodies of welded wire, whereas the cloth surrogates were covered by soft, resilient terrycloth. Both surrogates had long bodies that could be easily clasped by the infant rhesus monkey.

Figure 4-10 Surrogate mothers—one is made of wire and one is made of cloth. Experimenters would change which mother would be able to feed the infant.

Source: Harlow, McGaugh, and Thompson (1971, p. 58).

For half of the infants, a nipple by which they could feed themselves was attached to the wire mother, and for the other half the nipple was attached to the terrycloth mother. In either surrogate mother, the infants had the nutrition that they needed. If one thought that attachment was totally learned through reinforcement, then the infant monkeys should go to the mother from which they were fed. What do you think happened? What happened was a finding completely contrary to the learning theory interpretation. As the infants who fed on the wire mother grew, they showed decreasing responsiveness to her and increasing responsiveness to the cloth mother even though this mother had no food to offer (see Figure 4-11). From this, Harlow concluded that it is the contact comfort and not the feeding per se that binds the infant to the mother (see Figure 4-12).

Figure 4-11 Time spent on cloth and wire surrogate. Whether fed or not, the monkey infants like the cloth mothers better.

Source: Harlow, McGaugh, and Thompson (1971, p. 59).

Figure 4-12 Young monkey clinging to cloth mother.

Measuring Attachment

Part of Bowlby’s original interest in attachment came from observations of children in orphanages following World War II. Like the primates in Harlow’s experiments, these children had all of their physical needs met, but lacked a form of emotional and social connectedness. As part of a World Health Organization (WHO) project, Bowlby concluded that children deprived of their mothers were at risk for physical and mental illness. In particular, he concluded that separation from emotional caregivers could lead to severe anxiety and psychopathic personality (Bowlby, 1951).

Bowlby carefully observed children and recorded his observations in a series of books and articles focused on secure attachment as well as loss and separation anxiety (Bowlby, 1961, 1969, 1982, 1988). Bowlby had been influenced by ethology, which is the study of animal behavior. One classic example as described by the ethologist Konrad Lorenz is the imprinting of newborn ducks on their mother such that they will follow her wherever she goes. This will be discussed in the chapter on learning. Thus, Bowlby interpreted attachment from an evolutionary perspective emphasizing the survival value of attachment, especially as the human infant is beginning to crawl or walk on his or her own.

In terms of the general characteristics of attachment, Bowlby reported that children who develop a secure bond or attachment with a caregiver or parent, who is usually their mother, display patterns of activity that are especially strong from the end of the first year of life until about three years of age in relation to that caregiver. First, the infant shows distress when the caregiver leaves. Second, the infant smiles, makes noises, or shows other signs of pleasure when the caregiver returns. Third, the infant shows distress when approached by a stranger, unless the caregiver encourages the interaction. And fourth, the infant shows more exploratory behaviors in an unfamiliar situation when the caregiver is present.

Attachment Styles

Based on infants’ reactions to their caregiver, Mary Ainsworth developed the strange situation to research attachment patterns experimentally (Ainsworth, Blehar, Waters, & Wall, 1978). The basic procedure is to bring the infant and his or her mother into an unfamiliar room with toys. With the infant and mother alone, the infant is allowed to explore without the mother being involved. At this point a stranger enters and talks with the mother and then approaches the infant. During this time the mother leaves inconspicuously. The stranger reacts to the infant as appropriate. The mother then returns and greets and comforts the infant. Following this, the mother leaves the infant alone in the room, and the stranger returns. The mother then returns again and greets and picks up the infant while the stranger leaves. During this procedure, the researchers observe the infant’s reaction to the return of the mother.

Initially, Ainsworth described three patterns of attachment styles (Ainsworth, Blehar, Waters, & Wall, 1978). The first pattern, which is referred to as the secure attachment pattern, is characterized by the following pattern in which the infant: (1) engages in active exploration; (2) is upset when the mother leaves; and (3) shows positive emotions when the mother returns. The second pattern is the avoidant attachment pattern. In the avoidant style, the infant shows more interest in the toys than the mother and shows less distress when the mother leaves and less positive emotion when she returns. The third attachment pattern is referred to as anxious/ambivalent attachment pattern. In this pattern, the infant appears preoccupied with having access to the mother and shows protest on her separation. When she returns, the infant may show anger or ambivalence to her. This attachment pattern is associated with developing anxiety disorders later in life.

Later, other researchers suggested that a fourth pattern of attachment may exist that is characterized as disorganized/controlling attachment pattern. This attachment category was added when it was observed that some infants show disruptions in processing during the strange situation (Main & Solomon, 1990). That is, when their parent is present, these infants show disorganized behavior patterns or disorientation. Children with this attachment style tend to have problems dealing with psychological stress and a tendency to develop dissociative disorders later in life.

Of course, infants do not grow up in a vacuum, so it is also important to characterize the mothering style of the caregiver. With infants displaying secure attachment patterns, the style of the mother is consistent and responsive to her infant’s signals. On the other hand, mothers of infants showing avoidant patterns tend to be more rejecting and rigid and, in general, insensitive to the infants’ signals, including requests for bodily contact. Anxious/ambivalent patterns tend to be associated with inconsistent mothers who may be intrusive. Disorganized/controlling patterns tend to be associated with parents who show unpredictable abusive behavior or other behaviors that are frightening to the child. Mothers of these children have also been shown to be more likely to experience depression (O’Connor, Bureau, McCartney, & Lyons-Ruth, 2011). The complexity of the situation is highlighted by the fact that some infants are easier to care for than others. That is to say, some infants appear to be temperamentally more irritable than others, and thus could be more difficult for a caregiver to approach positively.

Attachment patterns can be seen as an internal roadmap or schema through which the person interprets his or her social experiences (Dykas & Cassidy, 2011). A secure pattern clearly has both physical and psychological benefits for the infant. There are also psychological values to trusting friends and other individuals as one moves through her lifespan. How about insecure attachment patterns, how are these protective? Bowlby (1980) suggests that these patterns prevent the infant from experiencing psychologically distressful experiences. If a caregiver is absent, inconsistent, and negative, then adopting a style that minimizes psychological pain would be protective. An important long-term research study described the role of attachment in the real world. This is described in the box: The World Is Your Laboratory—Romania Adoption Study.

The World Is Your Laboratory—Romania Adoption Study

Nicolae Ceaușescu was the head of state of Romania from 1967 to 1989. By the end of his rule, he had become brutal and repressive. Not only was he a brutal dictator who enforced his rule with the use of the secret police, but he also instituted strict policies requiring Romanians to have more children. He sought to increase the low birth rate in Romania by making divorce difficult and contraception and abortion illegal. He also dictated that women should have at least five children. To this end, Ceaușescu established the menstrual police. These were state gynecologists who conducted monthly checks of women of childbearing age who had not borne at least five children. To encourage additional children, families received a stipend for having more than two children but were also taxed for having fewer than five children. The number of new births did increase, although a number of these children were abandoned since the families could not afford to keep their children. The state encouraged placing these children in state orphanages.

After the fall of the Ceaușescu regime in 1989, it became clear that some 170,000 children had been placed in state institutions. The international media described these children as being “warehoused.” Initially, some of these children were adopted internationally, but this practice was later banned by Romania. The government after Ceaușescu sought to move some of the infants and children in the government facilities to foster families. This made possible a naturalistic study in which attachment relationships and future cognitive, emotional, and physiological development could be assessed and studied. Thus, there were a number of infants and children randomly assigned to be placed with families and others to receive the usual care in orphanages. These groups of children could also be compared to other children who were raised in their own family.

A team of researchers was able to follow a subset of these children over a number of years. Initially, measurements were taken (a baseline assessment) with the children who were assigned to a foster family as well as those who remained in the institution. These measurements allowed the researchers to know if there were later changes in terms of groups. The baseline measurements were followed by a comprehensive follow-up at 30, 42, and 54 months and 8 and 12 years. An initial study showed that those children in the institution displayed less attachment to a caregiver than those who had never been in the orphanages (see Figure 4-13).

Figure 4-13 Children in the institution displayed less attachment to a caregiver than those who had never been in the orphanages.

When assessed at 42 months, more children in foster care showed secure attachment style, whereas those who received care as usual at the orphanage showed more of the other insecure styles. The term “resistant” refers to the anxious/ambivalent attachment pattern (see Figure 4-14).

Figure 4-14 Security of attachment by group at 42 months.

In addition to attachment, cognitive development (as measured in terms of intelligence quotient (IQ)) was higher the earlier the child was placed in foster care. Physiological measures including EEG and brain volume were also shown to be influenced by type of caregiving situation.

Although we have known for more than 50 years that institutional care was associated with cognitive and emotional problems, the Romanian study with its randomized design allowed for greater validity in the results. Children come into the world seeking interactions with others. This interaction helps to develop cognitive, emotional, language, and motor development.

(Based on Nelson, Fox, & Zeanah, 2014.)

Thought Question: There are many situations in the world where orphanages are the only good alternative for caring for children. From what you’ve read so far, what three principles do you think are most important in designing and running an orphanage that results in psychologically healthy children?

CONCEPT CHECK

1. Describe the basic process of imitation learning in terms of actions. How have researchers extended that idea to understanding another’s internal experience and developing empathy?

2. What was the purpose behind creating the PATHS curriculum? What results have been shown with children who have gone through the program?

3. Theory of mind was initially researched by Premack and Woodruff in 1978 and continues to be an important topic in developmental psychology.

a. How would you define theory of mind?

b. Describe how experimental procedures have been used to study the theory of mind.

c. What do theory and research results tell us about theory of mind’s developmental process and timeline?

4. From John Bowlby’s perspective, why is attachment so critical in human development? Is there a critical period for attachment? What are the phases of the attachment process?

5. What did Harry Harlow’s studies with infant monkeys contribute to our understanding of the mechanisms of attachment? How did that, in turn, inform Bowlby’s study following World War II that focused on orphans’ psychological development?

6. Describe Mary Ainsworth’s different patterns of attachment style. How are attachment styles related to the mothering style of the caregiver?

7. From the research presented (including the Romania Adoption Study), in what ways can an individual’s attachment style in infancy impact his or her later life? Discuss this in terms of both positive and negative effects.

Development During Adolescence

When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years.

(Attributed to Mark Twain)

Adolescence is a time of great change, both in the brain and body, as well as in the relationships with one’s friends and parents. Similar changes are seen worldwide related to biological, psychological, and social development (Blakemore, 2019). During adolescence the individual changes from having a close connection with a family to developing a sense of one’s independence. Often this comes with emotional rejections and conflict with one’s parents. During this period the individual can begin enjoying the privileges allowed by society, such as driving a car, being part of the military, working, voting, and consuming alcohol, although the exact age differs by culture.

Adolescence has been characterized as a time in which an individual moves from a more family-oriented frame of reference to one of peer relations. Peer relationships during this period involve meeting and understanding new individuals as well as determining the types of relationships available. Sexuality and romantic interests develop during this period. Concomitant with these social and emotional changes are large changes in the brain. Overall, adolescents show an increased sensitivity to both positive and negative rewards than do either adults or younger children (Galván, 2013). Adolescents are particularly sensitive to being included in groups in terms of mood changes and anxiety feelings. As the adolescent moves into young adulthood, there is a shift from thinking about the self to taking the perspective of others.

In many cultures, adolescence is considered the time in which a male or female becomes an adult. Commemorating this entry into adulthood often involves a rite of passage or some special celebratory event for the individual. Some of these celebrations are religious, such as the time in which a Christian may join the church through confirmation. Jewish adolescents begin to follow religious rites, and this is celebrated by a Bar or Bat Mitzvah. In Mexico, a Quinceañera or fiesta de quince años is celebrated when a girl turns 15 years of age. Many other puberty celebrations or rites of passage are found throughout the world.

The word puberty actually comes from Latin, puber, which refers to being of marriageable age. Historically, rites of puberty marked this passage. As such, adolescence is a time of change to one’s body and the awakening of new interests and desires. These changes are associated with brain changes and reorganization (see Sturman & Moghaddam, 2011 for an overview).

Overall, changes during adolescence are seen in every domain, including physical, psychological, cognitive, and emotional (see Towbin & Showalter, 2008). Although the terms puberty and adolescence are commonly used interchangeably, technically there is a difference. Adolescence is a social, cognitive, and behavioral term developed in relation to society, whereas puberty is a series of biological events. The social and behavioral development of adolescence and the biological development of puberty actually involve different brain circuits (Sisk & Foster, 2004). However, as you can imagine, there is constant interaction between these systems.

Physical Changes in Adolescence

As puberty approaches, there is physical growth in terms of the size of hands and feet, and height and weight. This growth spurt is the greatest change in physical growth of the person since infancy. It peaks at about 12 years of age for females and age 14 for males. During this period, girls begin to appear more as they will as adults with wider hips, softer skin related to an increased layer of fat, and the appearance of breasts. Males show more body mass and broader shoulders. Facial features also change, including facial hair in males.

During puberty in both males and females, hormone levels increase throughout the body. For females, the ovaries produce the hormone estrogen. With this comes the growth of the breasts and sex organs. The vagina becomes larger and the muscles in the wall of the uterus become stronger. It is these muscles that will be utilized during the birth of a child. Externally, the labia (tissue around the vaginal opening) and the clitoris increase in size and become sensitive to touch. Girls then begin menstruation, although the ability to conceive is typically delayed a year or so.

For males, the testes produce the hormone testosterone. This is associated with the enlargement of the testes and growth of pubic hair. As the testes grow, the scrotum that contains them descends and darkens. The penis lengthens and becomes wider. About 13 to 14 years of age, sperm production begins. Although somewhat varied in time course, males show an increase in body hair of the face, arms and legs, and chest. The male voice becomes lower and muscle mass increases. Sexual thoughts and aggressive impulses increase in males.

Girls typically enter puberty about two years earlier than boys. However, there is great variability in the timing of puberty for both males and females. For example, extreme exercise or having an eating disorder will delay puberty. As with other signs of physical growth such as height, puberty is coming earlier today than it did 100 years ago in the industrialized nations. This may be related to better nutrition and public health, although other genetic and environmental factors have been shown to play a role in the timing of puberty.

Risk-Taking in Adolescence

Adolescents take more risk than either children or adults do (see Steinberg, 2007 for an overview). An increase in risk-taking leads to various types of accidents, unprotected sex, use of drugs, and even crime. In fact, automobile accidents are the leading cause of death among adolescents. This risk-taking cannot be seen as the lack of logical reasoning since 15-year-olds do as well as adults in laboratory-type cognitive reasoning tasks. Some risk-taking may be related to a lack of information since knowledge-based programs such as sex education do influence pregnancy rates. However, a more important factor seems to be making decisions in social and emotional situations.

One such social/emotional situation is being with peers. The desire to be with others along with the willingness to take risks, can influence decision making. For example, when schools were closed during the COVID-19 virus epidemic and adolescents were told to stay in place, some adolescents ignored the warning of health care professionals and met with their friends. This put them and others at risk for contracting the virus.

This risk-taking or impulsivity involves distinct brain networks related to the ability to inhibit (Whelan et al., 2012). Logical reasoning itself (absent social or emotional components) tends to be developed by about 15 years of age. However, frontal lobe development, which is related to planning and goals as well as inhibition, is not fully developed in adolescents and continues to develop well into an individual’s 20s. This suggests that adolescents have not yet developed the abilities to protect themselves from risk, especially when they are with their peers.

Overall, research in psychology and the neurosciences has shown that adolescence is a period of development in which the person is particularly sensitive to social environmental cues (see Blakemore & Mills, 2014 for an overview). Our brain networks during adolescence are actually more sensitive to these social cues than during either childhood or adulthood. Interestingly, our ability and sensitivity for cultural learning comes before adolescence.

Risk-Taking with Peers

One of the hallmarks of adolescent risk-taking is that it is more likely to occur in the presence of their peers (Chein, Albert, O’Brien, Uckert, & Steinberg, 2011). One of the risky behaviors seen in adolescents is driving. Using a stoplight driving game in an fMRI, Jason Chein and his colleagues compared the results of adolescents (14—18 years of age), young adults (19—22 years of age), and adults (24—29 years of age). The goal of the stoplight game is to drive through 20 intersections as fast as possible. At each intersection, the driver can either stop for the light and experience a short delay or take a risk and go through the red light without any delay. However, running the red light could result in a crash. All participants were also asked to bring a friend of their same age with them. Compared to young adults and adults, adolescents showed riskier decisions and crashes when they were observed by a friend (see Figure 4-15).

Figure 4-15 Risky decisions on the stoplight driving task when alone or being watched by a friend by age group.

Source: Chein, Albert, O’Brien, Uckert, and Steinberg (2011).

Chein and his colleagues also took functional MRI measures. The fMRI results showed differences in the left prefrontal cortex (PFC) by age. There were also differences in the right ventral striatum (VS) and the left orbito-frontal cortex (OFC) in terms of age and whether a friend was present. These areas are associated with making a decision in a social context. The greater activation of these areas suggests that adolescents saw risk-taking as more rewarding in the presence of a friend. Overall, this research shows that peer presence makes a greater difference in risk-taking, which is also seen in brain processes in adolescents compared with those beyond adolescence.

Moral Development in Childhood and Adolescence

Although adolescence is associated with greater risk taking, it is also a time that moral development such as a desire to change the world and make it a better place can be seen. In fact, adolescence is a period of rapid moral development. Let’s begin with how children make moral judgments. One question is to ask whether children younger than the age of six can differentiate between a moral judgment and a conventional one. An event that would require a moral judgment would involve aggression such as hitting or biting another, stealing such as taking another child’s possession, and psychological harm such as teasing. Events related to a conventional judgment would include not being neat or making a mess and breaking school rules such as playing in an area that is off-limits.

In a classic study, preschool children were asked to evaluate naturally occurring and hypothetical events involving moral and conventional transgressions (Smetana, Schlagman, & Adams, 1993). These researchers found that preschool children did make a distinction between the moral events and the conventional ones. The moral events were seen as more serious, wrong, and more deserving of punishment than the conventional events. Evolutionary psychologists view these types of results as suggesting that cultural and moral judgments rely on different systems of judgment and that moral transgressions are seen as more serious an offense than cultural ones.

When there are limited resources but there are needs, how does one make a decision about one’s actions? These resources can be related to time, physical ability, or money. A classic example of moral reasoning is to ask the question—who would you save first in a burning building, a 3-year-old or an 85-year-old? Adults can make a decision quickly. Some moral problems on the other hand are more complex. Would you be willing to hurt another person if it meant that three others would be saved from harm? These types of problems are not solved as quickly and often leave the person feeling uncertain about how to answer. In solving moral problems, children appear to change perspectives as they increase in maturity.

Given that moral and cultural norms are different, when do children begin to express moral decisions (see Colby, Kohlberg, Gibbs, & Lieberman, 1983; Sheskin, Chevallier, Lambert, & Baumard, 2014 for overviews)? In sharing with others, 9-year-olds have no problem sharing with others and selecting fair distributions. Five-year-olds tend to select a spiteful distribution over a fair one. Three-year-olds look to their own desires and do not share equally with others. Supporting the idea that moral reasoning has an emotional component, older children report more positive feelings after they engage in moral behavior. However, it should be noted that some researchers have made a distinction between the cognitive aspect of moral reasoning and moral emotions such as shame and guilt.

Based on the idea of stages of cognitive development suggested by Piaget, Lawrence Kohlberg (1963) asked if there are similar stages in moral development. As such, an individual’s way of solving a moral dilemma would be different at different ages. The type of reasoning given at one stage would be self-contained and different from that at another stage. Further, with development these stages become more complex and differentiated. Thus, in the same way that a child would solve the water jar conservation task differently at different ages, he or she would solve moral problems differently throughout their development. In terms of moral reasoning, obeying your parents would be a less differentiated answer than suggesting that societies work better if fairness is promoted.

Kohlberg used hypothetical situations to determine the level of moral development. Below are two examples of these moral dilemmas.

✵ In Europe, a woman was near death from cancer. One drug might save her, a form of radium that a druggist in the same town had recently discovered. The druggist was charging $2,000, ten times what the drug cost him to make. The sick woman’s husband, Heinz, went to everyone he knew to borrow the money, but he could only get half of what it cost. He told the druggist that his wife was dying and asked him to sell it cheaper or let him pay later. But the druggist said, “No.” The husband got desperate and broke into the man’s store to steal the drug for his wife. (Should the husband have done that?)

✵ There was a woman who had very bad cancer, and there was no treatment known to medicine that would save her. Her doctor, Dr. Jefferson, knew that she had only about six months to live. She was in terrible pain, but she was so weak that a good dose of a pain-killer like ether or morphine would make her die sooner. She was delirious and almost crazy with pain, and in her calm periods she would ask Dr. Jefferson to give her enough ether to kill her. She said she couldn’t stand the pain and she was going to die in a few months anyway. Although he knows that mercy killing is against the law, the doctor thinks about granting her request. (Should Dr. Jefferson give her the drug?)

How would you respond to these situations? For Kohlberg, the critical issue was not whether a person said yes or no to the dilemma, but the way in which the person reasoned. In fact, each dilemma could be answered either “yes” or “no” but with a different level of analysis. Based on research and theoretical considerations, Kohlberg outlined three levels of moral development with two stages in each (see Figure 4-16).

Figure 4-16 Levels of morality according to Kohlberg.

The first level is preconventional morality. At this level, rules are external to the individual. For a child, decisions are based on the rules of parents and teachers. The first stage of this level is punishment and obedience orientation. Bad actions are those that result in punishments and good actions are those that do not. The worse the punishment, the worse is the act. The second stage of this level is instrumental hedonism. This is the situation where you conform to the rules so that you will be rewarded or you do something for someone else so they will do something for you. This first level is typically seen in preschool children and those in the first few grades of elementary school.

The second level is conventional morality. With conventional morality, the individual has begun to internalize the values. As expected from developmental research, the individual is able to understand the perspective of others. The first stage of this level (stage 3) is that of good boy or good girl. Being accepted by others is important. People at stage 3 also evaluate others by their intentions. Stage 4 involves doing one’s duty. In the dilemma of the expensive drug, this type of reasoning would suggest that it is the husband’s duty to take care of his wife. This type of reasoning begins in elementary school. By adolescence, another type of reasoning occurs.

The third level is postconventional morality. The beginning of postconventional morality occurs as one becomes a young adult. As the name implies, this level uses higher-level moral principles. One might break local laws that are at odds with higher principles such as justice. Gandhi and Martin Luther King, Jr. both went against their conventional societal rules to present a higher purpose. People at this level would also seek to change existing laws if they were seen to violate larger universal principles. The movement for women’s vote at the beginning of the 1900s would be another example of this type of reasoning. Kohlberg saw stage 5 as reflecting a social contract that improves social welfare. Stage 6 was seen to reflect universal moral principles. However, Kohlberg dropped the use of stage 6 since it was so rarely used as a source of moral reasoning.

CONCEPT CHECK

1. Changes during adolescence are seen in every domain including physical, psychological, cognitive, emotional, and relationships. Describe an example of each.

2. What has research found concerning risk-taking in adolescents and the role of peers? How do these results change for individuals in their 20s?

3. There is a debate in our society as to whether adolescents have the psychological ability to understand crime in the same way as adults. Take a position pro or con and cite evidence to support your position.

4. Based on the idea of stages of cognitive development suggested by Piaget, Lawrence Kohlberg asked if there are similar stages in moral development. Describe the stages and levels Kohlberg proposed, as well as the ages when individuals would typically show that type of moral reasoning.

Lifespan Development and Adulthood

In the 1960s and 1970s, psychologists began to expand the concept of human development (see Lerner & Overton, 2010 for an overview). Prior to this time, the emphasis was on the developmental processes you have read about thus far in the chapter—development in infancy, childhood, and adolescence. To follow an individual across his or her lifespan in a theoretically integrated manner using psychological research was a new approach. This was referred to as lifespan development. Of course, many theorists over the years discussed the aging process and the types of questions asked, but these tended to lack a careful research focus.

For example, an early developer of analytic psychology, the Swiss psychiatrist Carl Jung suggested that the first half of life was about the development of one’s ego or personality with an emphasis on the external world. In so doing, one pays attention to his or her work, family, and society. On the other hand, for Jung the second half of life was about the self. This includes an understanding of both the positive and negative aspects of one’s self and one’s world. A person also considers how to pass values and understandings to the next generation. During the second half of life, a person begins to fully integrate his or her life with a focus on internal values. Overall, Jung suggested the first half of life was more about the external world and the second half about the internal world (see Jung, 1989). Although this perspective was based on a clinical practice, these ideas were not designed to be tested with research.

Others such as Daniel Levinson discussed lifespan development in terms of the seasons of one’s life (Levinson, 1978). He focused on the challenges you face or will face as you live your life. The initial stage occurs as you move from adolescence to becoming an adult. This is followed by the choices you make in your 20s in terms of who your friends are, what type of lifestyle you will live, whom you will love, and what values you will use to direct your life. Some people in their late 20s and 30s find themselves changing jobs through choice or being laid off. As people move into their 30s, there is a period of settling down. Some will have children and experience a change in focus. This may include a different understanding of who one is and how one fits into society. In one’s 40s and 50s, there are new realizations about life, and opportunities may decrease. As people move into their 60s, friends develop health problems such as heart attacks or even die. People may also ask questions concerning what they have accomplished. Some have criticized Levinson’s work suggesting that the individuals he studied may not represent current generations. In addition, there is the issue that the lifespan has increased.

Demographic changes during the last 100 years have also made us reconsider the concept of aging. In 1900, life expectancy was less than 50 years of age. In the 1930s, life expectancy in the United States was below 60 years of age, while in 2010 it was more than 78 years of age. That is almost a difference of 20 years of longer life. You even hear in the media that 70 is the new 50! Further, women are expected to live some five years longer than men (averaging 80 versus 75 years of age). Figure 4-17 shows life expectancy from 1970 to 2010. Some 30 or more countries have longer life expectancies than the United States; for example, Japan has a life expectancy of 83 years. The larger perspective is that those of you who are currently about 20 years of age will have 60 more years of life to live. In fact, it is estimated that by 2050 more than 2 billion people worldwide will be more than 60 years of age (Huentelman et al., 2020). This raises a number of questions as to how to use one’s extended lifetime.

Figure 4-17 Changes in US life expectancy. We continue to live longer.

Erikson and Psychosocial Stages

One of the first theorists to present a map of lifespan development was Erik Erikson. He was born in Frankfurt, Germany in 1902. He was initially influenced by Sigmund Freud and worked with Freud’s daughter, Anna Freud. Erikson expanded psychodynamic concepts through observations of children in several cultures and an understanding of biology. Based on these influences, Erikson suggested that people throughout the world experience eight major psychosocial stages (see Table 4-2). During each of these stages, there is a major conflict or question that must be answered.

At each stage the person is asking who am I and how do I relate to the world, myself, and others. During the first year of life the infant determines whether he can trust his environment or not. With good conditions, the infant gets the attention, caring, and food that is needed for development. If this is the case, the infant has a sense that the world is safe and reliable. However, if the caregiving is inconsistent or the infant does not get the attention needed, then he understands the world as unsafe and not a situation to be trusted.

As the infant becomes a toddler, movement and new perspectives become possible. In the family the child is encouraged to become a person with wishes and desires. If this is not available, then doubt in one’s own behavior can be seen. Following this, the child becomes part of groups, whether it is family, playschool, or group play. With this come the social emotions, such as guilt for breaking rules. On the individual level, the child can have goals that may be different from the group. A positive resolution to the conflict is for the child to experience purpose more than guilt. Entering elementary school, the child spends more time with other children and begins to see where they stand in terms of physical, emotional, and cognitive abilities. As the child becomes an adolescent, she becomes part of different groups and has the opportunity to try out different social roles. This leads to a sense of identity. If the adolescent is unable to do this, role confusion and identity problems result. In young adulthood, the person begins to make more long-term decisions. When successful, the person is able to experience intimacy in both social and sexual relationships. By middle adulthood, the person can focus on creativity in her world. She can also consider how to teach and mentor others. If this does not happen, there is a sense of stagnation. As one enters old age, the person has the chance to reconsider what is important to him and to look back on his life. It is at this point that the individual can come to value and accept the decisions and accomplishments that he has made. If not, the person will experience despair for the life he wished he had lived.

Successful Aging

At one time, aging was discussed in terms of loss of cognitive functions such as memory and the increase in medical problems (Pluvinage & Wyss-Coray, 2020; Wulff et al., 2019). A common view from the middle of the last century was that a person would work and then retire to a community in a state such as Florida or Arizona. It was often assumed that the person would relax and not engage in high-level intellectual or physical activities. However, today the manner in which people age follows a number of different pathways. Some people do show mental or physical deterioration as they age. Disorders such as Alzheimer’s are a common experience of this group. However, others retain both physical and mental abilities as they age. The study of this last group has been referred to as successful aging.

One of the early studies of successful aging was conducted in the 1930s. In 1937, the philanthropist William T. Grant gave money to study the lives of “people who are well and do well.” These individuals were studied for 35 years (see Vaillant, 2002 for overview). The basic conclusions from this study were that:

✵ psychopathology is always with us;

✵ health is the way we react to conflict, not the absence of conflict;

✵ not one of the people, some of whom were very successful, were without problems.

Although no individual was without problems, the manner in which they coped with their problems was associated with better or worse health outcomes. Immature defenses such as blaming others or taking it out on one’s self were associated with the worst health outcomes. More mature defenses such as acceptance or humor were associated with the best health outcomes. These results are shown in Figure 4-18.

Figure 4-18 The relationship between maturity of defenses and decline in physical health.

Successful aging is now considered one aspect of lifespan development. Successful aging is seen to include three main components (Rowe & Kahn, 1997). The first component is a low probability of disease and disease-related disability. The second component is high cognitive and physical functional capacity. And the third is an active engagement with life. Of course, these components are inter-related. For example, choosing a healthy lifestyle in terms of food and exercise is one way to reduce the likelihood of disease. Also, being involved with other people in terms of social networks or marriage has been shown to be protective. A number of retired people continue working in either a volunteer or self-employed manner, which gives meaning to their lives.

Of course, even in those who age successfully, changes do take place. As we age, the speed of our reactions decreases. Actually, your ability to play video games begins to decrease in your 20s. Your ability to perform tasks that require reasoning and spatial abilities also decreases. As one becomes older, difficulty with hearing and vision becomes more obvious. Many older adults find driving at night to present problems in terms of seeing the edge of the road and reacting to the lights from other cars.

Although all individuals experience changes with aging, older people actually report that they feel younger than they actually are and are satisfied with their aging (Kleinspehn-Ammerlahn, Grühn, & Smith, 2008). Further, people more than 60 who report that they enjoy life had fewer problems in day-to-day abilities some eight years later than those who reported they did not enjoy life (Steptoe, de Oliverira, Demakakos, & Zaninotto, 2008).

One strong finding across the lifespan is that individuals in committed romantic relationships have longer, healthier, and happier lives than unmarried individuals (see Diamond, Fagundes, & Butterworth, 2010). This is also true for those who have a same-sex relationship. One key variable is that the emotional relationship is protective from stress factors. However, over the lifespan, marital satisfaction is highest at the beginning of the relationship and after children leave the house. It is lowest after the birth of the first child. Older and younger couples appear similar in terms of agreements and disagreements over leisure, intimacy, money, housework, and other concerns.

How old will you be in the year 2050 or 2060? As you think about your age at this time, you can ask if there are simple things you can do to help you age successfully. As noted, research has shown an important role for exercise and social support in a healthy lifestyle and successful aging (Voss, Vivar, Kramer, & van Praag, 2013). Exercise is thought to play an important role in aging by promoting healthy cardiovascular function. That is, exercise increases blood flow to the entire brain. Exercise also protects the brain from the adverse effects of aging. Research with animal models has shown that exercise slows the expression of Alzheimer’s-like disorders.

In a review of literature from different areas, Kramer and Erickson (2007) suggest that exercise provides multiple routes to enhancing cognitive vitality across the lifespan. These include both the reduction of disease risk as well as improvement in molecular and cellular structures of the brain, including better blood supply to the brain through new capillaries. This, in turn, increases brain function. Exercise also increases the size of the hippocampus and improves memory (McAuley et al., 2011). Further, it is suggested that aerobic exercise affects executive function more than other cognitive processes.

Following more than 700 older individuals without neurocognitive disorders for several years, Aron Buchman and his colleagues (2012) found that daily physical activity slowed cognitive decline. Exercise was also associated with a lower risk for developing Alzheimer’s disease. Although performing various types of cognitive tasks such as crossword puzzles or speaking a second language are also associated with successful aging, these brain effects appear to be more localized in those areas of the brain related to the specific task.

In order to better help articulate the causal role of exercise, Lindsay Nagamatsu and her colleagues (2013) randomly assigned older individuals who were beginning to show mild cognitive impairment to one of three groups. The first group received resistance training and lifted weights. The second group received aerobic training and walked outdoors at a level that increased their heart rate. The third group received balance and stretching exercises. The third group served as the control group. After six months of twice-weekly exercise, the first two groups improved in memory functions. This was seen more strongly on a difficult spatial memory test. The aerobic group also improved performance on the verbal memory test. The important point of this study is that six months of exercise can improve memory in 70-year-olds.

Social support has also been associated with a reduced risk for neurocognitive disorders. Two of these factors are the size of one’s network of friends and whether one is married or not. As suggested in studies of the social brain, understanding and maintaining networks of friends requires a variety of cognitive resources, which in turn offer a reserve for dealing with brain pathologies. One study followed 16,638 individuals over the age of 50 for six years. Those individuals who were more socially integrated and active showed less memory loss during the six-year period (Ertel, Glymour, & Berkman, 2008).

CONCEPT CHECK

1. In the 1960s and 1970s the concept of human development was expanded to include lifespan development. What changes did this bring to the way psychologists study human development in terms of scope, theoretical research, and demographic necessity?

2. 2. A number of people have proposed that the concept of lifespan development can be organized around the problems individuals face at different critical periods of their lives and how they solve those problems. What were the life problems and their critical periods presented by the following people:

a. Carl Jung?

b. Daniel Levinson?

c. Erik Erikson?

d. William T. Grant?

3. What are the three main components of successful aging? Cite evidence that shows the value of exercise and social relationships in successful aging. What will you consider starting now so that you age successfully?

Summary

Learning Objective 1: Discuss the brain, sensory, and motor developments that take place during infancy.

Developmental psychology is the study of the cognitive, emotional, and motor development of humans across their lifespan. This development is influenced by a number of factors including culture, parent and peer involvement, and brain processes.

There are two critical periods in terms of brain development over one’s life. The first occurs in the womb, and the second is during adolescence. During gestation and the early years of life, the brain is establishing its cortical connections and growing neurons at an amazing rate. The areas of the infant’s brain with increasing connections involve visual, auditory, and motor processing. Language and spatial orientation, which involve the parietal areas, don’t fully develop until around puberty. Executive functions involving goals, reasoning, as well as integration of information and social processes continue to develop until your 20s.

Psychologists often discuss development in terms of human processes, including motor development, cognitive development, language development, social development, and so on. However, if you watch infants through their first years of life, you will see that there is a complex interaction involving all of these systems. Not only do human infants actively search their environment, they have expectations of what should happen next. Not only do infants have expectations, but they also act as “little scientists” and try to test out their ideas. When their expectations are not met, they try to learn from what they experience.

Motor development in infants proceeds in two directions. The first is from head to toe, and the second is from the midline of the body to the periphery. At about 2 months of age, the infant develops the muscles necessary for raising his or her head. About a month later, the infant develops the muscles of the torso necessary to roll over and sit in a high-chair. During the next six months, the infant can begin to crawl. At the first year of age, infants can begin to stand while holding on to a low table and take steps on their own. Likewise, development goes from the midline in which infants can move their arms and legs before they can actually use their hands to purposely grab an object.

Learning Objective 2: Discuss cognitive development based on the theories of Piaget and Vygotsky.

Cognitive development refers to the way we reason and use language, as well as traditional intellectual abilities such as memory and problem solving.

Jean Piaget is considered to have created the field of cognitive development. His work was mainly based on the observation of children at different ages. One important contribution was the idea that a child has a different schema or set of assumptions at different periods of his or her life. Through his observations of how children solve problems, as well as the mistakes they make, Piaget suggested there were four periods or stages of development that correspond with a child’s age: (1) sensorimotor, (2) preoperational, (3) concrete operations, and (4) formal operations.

Russian psychologist Lev Vygotsky offered a sociocultural perspective to cognitive development. Whereas Piaget emphasized the interaction with the physical environment, Vygotsky stressed the social and cultural environment.

We all come into the world with bodily emotional responses all our own—a constellation of emotional and behavioral responses referred to as temperament. Temperament is seen as a broad set of emotional and behavioral reactions in which both genetic and environmental factors play a role.

Learning Objective 3: Describe the aspects of social development and how we make emotional and social connections with others.

Infants are able to learn important aspects of social development by watching others and making emotional and social connections, especially parents and other caregivers.

What happens in your brain when you see someone wave or clap her hands? One intriguing answer to this question comes from research that suggests the neurons in your brain fire as if you had performed the same actions. These neurons are called mirror neurons. Some researchers suggest that this brain process may lie at the basis of imitation learning, as well as other human social phenomena, including language and empathy.

Theory of mind is the capacity to infer another person’s mental state from their behavior. Mental state can include purpose, intention, knowledge, belief, thinking, doubt, pretending, liking, and so forth. Theory of mind is an important topic in developmental psychology.

John Bowlby developed a theoretical understanding of interpersonal relationships based on the interactions of a child with his or her parents, which he referred to as attachment. Mary Ainsworth described three patterns of attachment styles: (1) secure attachment pattern, (2) avoidant attachment pattern, and (3) anxious/ambivalent attachment pattern. Later researchers suggested a fourth attachment style: (4) disorganized/controlling attachment pattern. Numerous studies have shown attachment patterns to be relatively stable across the lifespan in a number of areas.

Learning Objective 4: Discuss the physical, psychological, cognitive, and emotional domains that occur during adolescence

During adolescence, there is physical growth in terms of the size of hands and feet, and height and weight. This growth spurt is the greatest change in physical growth of the person since infancy. During puberty, in both males and females, hormone levels increase throughout the body. Girls typically enter puberty about two years earlier than boys, however there is great variability in the timing of puberty for both males and females.

Adolescence has been characterized as a time in which an individual moves from a more family-oriented frame of reference to one of peer relations. Concomitant with these social and emotional changes are large changes in the brain. Research suggests that, from childhood to adulthood, the brain goes from a largely undifferentiated system to one composed of specialized neural networks.

Adolescents take more risk than either children or adults do. This risk-taking or impulsivity involves distinct brain networks related to the ability to inhibit. Peer presence makes a greater difference in risk-taking, which is also seen in brain processes in adolescents compared with those beyond adolescence. Overall, adolescents show an increased sensitivity to both positive and negative rewards than do either adults or younger children.

Learning Objective 5: Discuss the concept of lifespan development and adulthood.

In the 1960s and 1970s, psychologists began to expand the concept of human development to include lifespan development—following individuals across their lifespans in a theoretically integrated manner using psychological research.

One of the first theorists to present a map of lifespan development was Erik Erikson. He proposed that people experience eight major psychosocial stages—each stage defined by a major conflict or question that must be answered. His eight stages are: (1) trust versus mistrust; (2) autonomy versus shame and doubt; (3) initiative versus guilt; (4) industry versus inferiority; (5) identity versus role confusion; (6) intimacy versus isolation; (7) generativity versus stagnation; and (8) integrity versus despair.

At one time, aging was defined primarily in terms of loss of cognitive functions such as memory and an increase in medical problems. However, today the manner in which people age follows a number of different pathways. Some people do show mental or physical deterioration as they age. However, others retain both physical and mental abilities as they age. The study of this last group has been referred to as successful aging. Research shows an important role for exercise and social support in a healthy lifestyle and successful aging.

Study Resources

Review Questions

1. This chapter opened by saying: “We are all children who grew up.” Now that you have come to the chapter’s close, how would you answer the following questions based on the ideas and evidence presented:

a. What factors do you think influenced your development?

b. What would you see as the critical factors?

c. Was it a series of single events or a more continuous process?

2. In Walter Mischel’s study, will 5-year-old Amy eat the single marshmallow right away or will she be able to wait and receive the reward of two marshmallows? Of course, we don’t know, but what would the following researchers say are the critical factors in determining what she will do:

a. Charles Darwin?

b. John Watson?

c. Jean Piaget?

d. Lev Vygotsky?

e. John Bowlby?

f. Harry Harlow?

g. Mary Ainsworth?

h. Nelson, Fox, and Zeanah in the Romanian adoption study?

3. In this chapter, most of the coverage of the stages of human development across the lifespan begins at birth. To complete the picture, construct a timeline of the human brain and nervous system development that happens in the womb before birth.

4. In all primates, early development is the foundation from which the rest of an individual’s life spins out. Humans share some developmental aspects, for example, certain reflexes, with other primates. However, some capabilities are considered to be uniquely human. From what has been presented in this chapter, create a table showing developmental aspects and processes humans share with other primates and those that are uniquely human.

5. One of the tasks of preschool and elementary school children is the integration of cognitive, emotional, and motor tasks. Mark Greenberg, the lead developer of the PATHS curriculum, has asked you to develop a brief statement to mail to elementary school principals describing the program, its purpose, target audience, and evidence of outcomes. What would you write?

6. This chapter has focused on human development from the perspective of the developing individual. Now take the perspective of the parent. Briefly describe the role of the parent throughout the developmental stages: infancy, childhood, adolescence, and adulthood.

7. Changes during adolescence are seen in every domain including physical, psychological, cognitive, emotional, and relationships. You’ve just come through adolescence yourself. Given what you’ve read so far in this book and what you’ve experienced in your own life, how would you assess the importance of each of these domains and their interrelationships in your own development?

8. Based on what we know about human development through the lifespan, what recommendations would you make to the following organizations to foster successful development during the period they cover:

a. Mother—baby clinic?

b. Day care or nursery school?

c. Primary school?

d. High school?

e. College?

f. Community psychology clinic?

g. Retirement community?

For Further Reading

✵ Hrdy, S. (1999). Mother Nature. New York: Pantheon.

✵ Hrdy, S. (2009). Mothers and Others. Cambridge, MA: Harvard University Press.

✵ Nelson, C., Fox, N., & Zeanah, C. (2014). Romania’s Abandoned Children. Cambridge, MA: Harvard University Press.

✵ Taylor, S. (2001). The Tending Instinct. New York: Henry Holt, & Co.

Web Resources

✵ CDC fetal alcohol disorder—https://www.cdc.gov/ncbddd/fasd/facts.html

✵ CDC alcohol during pregnancy—https://www.cdc.gov/ncbddd/fasd/alcohol-use.html

✵ Unexpected event in infants—http://www.npr.org/blogs/ed/2015/04/02/396812961/why-babies-love-and-learn-from-magic-tricks and the supplemental information published online at http://www.sciencemag.org/content/348/6230/91/suppl/DC1

Key Terms and Concepts

accommodation

assimilation

attachment

cognitive development

concrete operations

critical or sensitive periods

dynamic system theory

habituation

imitation learning

intrinsic motivation

lifespan development

mirror neurons

moral development

object permanence

patterns of attachment styles

plasticity

preoperational stage

psychosocial stages

schema

secure base

sensorimotor stage

strange situation

successful aging

temperament

theory of mind