10.1 Social Behavior - Social Thinking

MCAT Behavioral Sciences Review - Kaplan Test Prep 2021–2022

10.1 Social Behavior
Social Thinking


After Chapter 10.1, you will be able to:

· Describe interpersonal attraction, including the factors that influence interpersonal attraction

· Recall the meaning of the term aggression, including examples of aggressive behaviors

· List the four types of attachment and how they affect childhood behavior

· Identify the common types of social support

· Explain the relationship between altruism and inclusive fitness

Social behaviors involve interactions with others. These may flow from positive feelings, such as attraction or attachment, or they may flow from negative feelings, such as aggression.


Have you ever wondered what makes some people friends and others enemies? How second graders choose their best friends? Why you keep eyeing that cute person in your physics class? Social psychologists call this phenomenon of individuals liking each other interpersonal attraction. Researchers have found several factors that affect attraction, including similarity, self-disclosure, reciprocity, and proximity. Outward appearance also plays a role; the more symmetric someone’s face is, the more physically attractive we find him or her to be. Humans are also attracted to individuals with certain body proportions approximating the golden ratio (1.618:1).

Key Concept

Interpersonal attraction is influenced by many factors, including physical characteristics, similarity, self-disclosure, reciprocity, and proximity.

We tend to be attracted to people who are similar to us in attitudes, intelligence, education, height, age, religion, appearance, and socioeconomic status. One reason for this may be convenience: it’s easier to spend time together if you both want to go on a bike ride or if you both enjoy Thai food. Also, people are drawn to having their values and choices validated by another person. So why is there a cliché about opposites attracting? Social psychologists find that attraction also occurs if opposing qualities match up with each other; for example, a nurturer is attracted to someone who craves being nurtured. Notably, successful complementary relationships still have fundamental similarities in some attitudes that make the complementary aspects of the relationship work.

Another component of attraction lies in the opportunity for self-disclosure, or sharing one’s fears, thoughts, and goals with another person and being met with nonjudgmental empathy. Engaging in this behavior deepens attraction and friendship. This must be a reciprocal behavior, however. Revealing one’s innermost secrets creates a sense of vulnerability that, if not met by the other person, can be interpreted as being taken advantage of. Reciprocity is important in other aspects of interpersonal attraction as well. Reciprocal liking is the phenomenon whereby people like others better when they believe the other person likes them. Researchers have shown that even if we disagree with others on important issues, we will have increased interest in them if we have indications that they like us.

Finally, proximity, or just being physically close to someone, plays a factor in our attraction to him or her. Studies have shown that we are more likely to form friendships with people in the same dorm as us or with the people who sit closest to us in class. Part of this is convenience; it’s easier to have conversations and make plans with people in the same area. Another explanation is the mere exposure effect or familiarity effect, the tendency for people to prefer stimuli that they have been exposed to more frequently. You may have observed this in your everyday life: Have you disliked a song the first time you heard it, only to find yourself singing along and saying, I like this song! after hearing it many more times? This principle is also used in marketing: the more people hear the name of a product, the more likely they are to be attracted to and purchase that product.


Aggression is defined as a behavior that intends to cause harm or increase social dominance. Aggression can take the form of physical actions as well as verbal or nonverbal communication. Ethologists study aggression in terms of the interactions between animals in natural settings. Aggression in these settings can include bodily contact, as seen in Figure 10.1, but most displays of aggression are settled by threat and withdrawal without actual bodily harm. Threat displays are common in both animals and humans. Before a fight, a man might puff up his chest or pull back his fist to threaten another person. This display may or may not result in physical harm or violence. Other examples of aggression include a bully hurling insults at another child or a teenage gang member making threatening gestures to a member of another gang.

ImageFigure 10.1. Aggression Following Threat Displays of Elephant SealsWhile threat displays may lead to violence, as seen here, threat displays commonly lead to withdrawal to prevent fights.

What is the purpose of aggressive behavior if it causes so much destruction? Evolutionarily, aggression offers protection against perceived and real threats. Aggression helped our ancestors fight off predators. It also helps organisms gain access to resources such as food, additional territory, or mates. In cases of limited resources, aggression could be the deciding factor that allows one to pass on genes.

From a biological perspective, multiple parts of the brain contribute to violent behavior. The amygdala is the part of the brain responsible for associating stimuli and their corresponding rewards or punishments. In short, it is responsible for telling us whether or not something is a threat. If the amygdala is activated, this increases aggression. However, higher-order brain structures, such as the prefrontal cortex, can hit the brakes on a revved-up amygdala, reducing emotional reactivity and impulsiveness. Reduced activity in the prefrontal cortex has been linked to increased aggressive behavior.


The prefrontal cortex is critically important to managing the limbic system, which is important in managing emotion and stress. These roles of the prefrontal cortex are discussed in Chapter 5 of MCAT Behavioral Sciences Review.

Aggression is also under hormonal control. Higher levels of testosterone have been linked to more aggressive behavior in both males and females. The higher levels of testosterone in men compared to women may explain the fact that men are generally more aggressive than women across cultures and that men commit a disproportionate majority of violent crimes.

Real World

Alcohol has been shown to increase aggressive behavior. Alcohol impairs judgment and limits one’s ability to control aggressive reactions. It also makes one feel less inhibited by social mores that would normally restrict aggressive behavior.

Beyond the biological contributions to aggressive behavior, studies have found many psychological and situational predictors of aggression. Do you find yourself snapping at people more when you’re in pain? Have you ever gotten annoyed with a waiter when you were extremely hungry? Such responses are accounted for by the cognitive neoassociation model, which states that we are more likely to respond to others aggressively whenever we are feeling negative emotions, such as being tired, sick, frustrated, or in pain. This can also be seen on a large scale: riots are more likely to happen on hot days than cool ones; drivers without air conditioning are more likely to honk at other drivers than those with air conditioning.

Another factor that contributes to aggressive behavior is exposure to violent behavior. The effects on children of media portrayals of violence continue to be a hot topic. Research findings are mixed but tend to show that viewing violent behavior indeed correlates to an increase in aggressive behavior. The contribution of modeling to violence in children was also explored in Albert Bandura’s Bobo doll experiment, described in Chapter 3 of MCAT Behavioral Sciences Review.


Attachment is an emotional bond between a caregiver and a child that begins to develop during infancy. While parental figures are most common, emotional bonds can occur with any caregiver who is sensitive and responsive during social interaction. After World War II, psychiatrist John Bowlby noticed the negative effects of isolation on social and emotional development in orphaned children and started the study of attachment. In the 1970s, psychologist Mary Ainsworth expounded on this theory, saying that infants need a secure base, in the form of a consistent caregiver during the first six months to two years of life, from which to explore the world and develop appropriately. Four main types of attachment styles have been described: secure, avoidant, ambivalent, and disorganized.

Key Concept

In attachment, a secure base is a caregiver who is consistent, available, comforting, and responsive.

Secure Attachment

Secure attachment is seen when a child has a consistent caregiver and is able to go out and explore, knowing that he or she has a secure base to return to. The child will be upset at the departure of the caregiver and will be comforted by the return of the caregiver. The child trusts that the caregiver will be there for comfort, and while the child can be comforted by a stranger, he or she will clearly prefer the caregiver. Having a secure attachment pattern is thought to be a vital aspect of a child’s social development. Children with avoidant, ambivalent, or disorganized attachment can have deficits in social skills. Collectively, these attachment types are known as insecure attachment.

Avoidant Attachment

Avoidant attachment results when the caregiver has little or no response to a distressed child. Given the choice, these children will show no preference between a stranger and the caregiver. They show little or no distress when the caregiver leaves and little or no relief when the caregiver returns.

Ambivalent Attachment

Ambivalent attachment occurs when a caregiver has an inconsistent response to a child’s distress, sometimes responding appropriately, sometimes neglectfully. As such, the child is unable to form a secure base because he or she cannot consistently rely on the caregiver’s response. The child will be very distressed on separation from the caregiver but has a mixed response when the caregiver returns, often displaying ambivalence. This is sometimes referred to as anxious—ambivalent attachment because the child is always anxious about the reliability of the caregiver.

Disorganized Attachment

Children with disorganized attachment show no clear pattern of behavior in response to the caregiver’s absence or presence, but instead can show a mix of different behaviors. These can include avoidance or resistance; seeming dazed, frozen, or confused; or repetitive behaviors like rocking. Disorganized attachment is often associated with erratic behavior and social withdrawal by the caregiver. It may also be a red flag for abuse.

Real World

As a physician, you will be a mandated reporter. This means that you are required by law to report suspected cases of child abuse. Remember: It is better to report and be incorrect than to miss a potentially fatal scenario.

Behavioral Sciences Guided Example With Expert Thinking


Expert Thinking

The Strange Situation is an experimental procedure used to assess attachment in infants who are between 9 and 18 months old. The procedure occurs over the course of twenty-one minutes and progresses as follows:

1. 1. The parent and child are introduced to the experimental room.

2. 2. The parent and child are left alone in the room. The infant is allowed to explore the room. The parent does not participate.

3. 3. A stranger enters the room, converses with the parent, and attempts to engage with the child.

4. 4. The parent conspicuously leaves the room, and the child is left with the stranger.

5. 5. The parent returns and comforts the child.

6. 6. Both the parent and the stranger leave, and the child is left alone.

7. 7. The stranger returns and attempts to engage with the child.

8. 8. The parent returns and comforts the child, and the stranger conspicuously leaves.

Researchers observe the amount of exploration the child engages in, reactions to the stranger, reactions to the absence of the parent, and the child’s behavior upon reunion with the parent.

Experimental procedure. I'll take a brief moment to picture each step, but I'll have to return to this list if a question asks for details.

Not a traditional experiment so no real IV, the differing input is the child and his or her relationship to the parent, and the output is the child’s behavior/attachment style.

This procedure has been replicated with nonhuman animals. In particular, it has been shown that dogs tend to form secure attachments with their owners. This procedure has been attempted with cats, but it appears that cats’ behaviors may not serve the same function as behaviors of humans, and as such it is difficult to use procedures developed for humans to assess cat attachment. Furthermore, individual cats’ behaviors are inconsistent throughout the procedure, possibly because the experimental procedure is a scenario that cats do not frequently encounter outside the laboratory.

Attachment in nonhuman animals. Dogs are secure and cats are complicated.

Adapted from: Potter A, Mills DS (2015) Domestic Cats (Felis silvestris catus) Do Not Show Signs of Secure Attachment to Their Owners. PLoS ONE 10(9): e0135109. https://doi.org/10.1371/journal.pone.0135109

A child exposed to the Strange Situation was uninterested in exploring the room in the presence of either parent or stranger, and did not emotionally engage with either individual. In what ways do dogs’ attachment behaviors and style differ from those of the child? What experimental limitations do the researchers point out regarding assessing attachment in cats?

The beginning of the question stem presents a scenario in which a child was reluctant to explore his or her surroundings, regardless of who was present. This description will have to be matched to our outside content knowledge regarding attachment. The different attachment styles are content we should know for the MCAT, and avoidant attachment is characterized by children who show no substantial behavioral change based on the presence or absence of a parent. Behaviorally, we can conclude the child described is displaying an avoidant attachment style. Dogs were described in the article as demonstrating secure attachment, so we’ll want to recall the characteristics of a secure attachment and apply them to this situation. In secure attachment, the subject may or may not show distress when left with a stranger, but will definitely prefer the caregiver. The dogs must have displayed distress when left alone but were easily comforted when the caregiver returned. Specifically, then, the difference between the child and a typical dog should be twofold: the dogs should show greater engagement and positive response with their caregiver as compared to this child, and the dogs should show more distress when left alone without the caregiver as compared to the child.

The answer to the second question requires that we approach the problem in a similar way, this time applied to experimental design. We’ll need to consider the description we were given and attempt to match the description to a vocabulary word or concept we’ve studied. Here, the researchers noted two issues. The first was that the behaviors measured in cats did not serve a function with respect to attachment. Since cats aren’t social animals, trying to evaluate their behavior in a social context might be inappropriate. The experiment might not actually be measuring what it seeks to measure, which is a problem with internal validity. The author also mentions that the scenario presented in the experiment might not have a real-world analogue. When an experimental procedure might not actually apply to situations outside the lab, the experiment can be said to lack external validity.

In sum, the dog displayed secure attachment, while the infant displayed avoidant attachment. The application of this methodology to cats potentially lacks both internal (not measuring the targeted variable) and external (not bearing relevance to real-world analogues) validity.


In psychology, social support is the perception or reality that one is cared for by a social network. Social support can be divided into many different categories: emotional, esteem, material, informational, and network support. While social support is present at all times, it is often most pronounced—and necessary—when someone suffers a personal or family tragedy.

Emotional support is listening, affirming, and empathizing with someone’s feelings. It’s the I’m sorry for your loss condolence card or a trip to the hospital to visit a sick relative. Many people equate social support with emotional support, but other forms of support exist as well.

Esteem support is similar, but touches more directly on affirming the qualities and skills of a person. Reminding others of the skills they possess to tackle a problem can bolster their confidence. For example, consider a friend who has missed a significant amount of school due to illness. Telling her that she should have no problem making up the work because she is smart and an efficient worker would be providing esteem support.

Material support, also called tangible support, is any type of financial or material contribution to another person. It can come in the form of making a meal for friends after they have lost a loved one or donating money to a person in need.

Informational support refers to providing information that will help someone. You will spend much of your career providing informational support to patients as you explain their diagnoses, potential treatment options, and risks and benefits of those treatment options.

Network support is the type of social support that gives a person a sense of belonging. This can be shown physically, as demonstrated in Figure 10.2, or can be accomplished through gestures, group activities, and shared experiences.

ImageFigure 10.2. Network SupportA group hug creates a sense of belonging.

No matter the form, all of these social supports offer many different types of health benefits. Social support helps reduce psychological distress such as anxiety and depression. People with low social support show higher levels of major mental disorders, alcohol and drug use, and suicidal ideation. Beyond these intuitive improvements in mental health, there are also improvements to our physical health. Studies have found that people with low social support have a higher mortality risk from many different diseases, including diabetes, cardiovascular disease, and cancer. Strong social support appears to correlate with immunological health, too: those with higher social support are less likely to get colds and recover faster when they do.


Many behaviors have neurological corollaries. Here, we will look at some specific behaviors and the brain regions that are implicated in causing them.


The behavior of foraging, or seeking out and eating food, is driven by biological, psychological, and social influences. Biologically, hunger is driven by a complex pathway involving both neurotransmitters and hormones. The sensation of hunger is controlled by the hypothalamus. Specifically, the lateral hypothalamus promotes hunger, while the ventromedial hypothalamus responds to cues that we are full and promotes satiety. Thus, damage to the lateral hypothalamus will cause a person to lose all interest in eating; meanwhile, damage to the ventromedial hypothalamus will result in obesity because the individual never feels satiated. Foraging is also impacted by genetics. Certain genes play a role in the onset of foraging behavior and the division of tasks between members of the same group. Some species forage together while others engage in solitary foraging.

Cognitive skills play a role in the success of both solitary and group foraging. These skills include spatial awareness, memory, and decision making. In species that forage as a group, foraging is primarily a learned behavior. Young individuals learn through observing how to find and consume food and how to determine what is safe to eat, as shown in Figure 10.3. Animals also learn how to hunt by watching others. Some animals, such as wolves, hunt in packs that have strict rules regarding the order in which individuals are allowed to eat after a successful hunt.

ImageFigure 10.3. Foraging Is Learned through Observational Learning

Mating and Mate Choice

A mating system describes the organization of a group’s sexual behavior. Mating systems seen among animals include monogamy, polygamy, and promiscuity. Monogamy refers to an exclusive mating relationship. Polygamy involves a male having exclusive relationships with multiple females (polygyny) or a female having exclusive relationships with multiple males (polyandry). Promiscuity refers to a member of one sex mating with any member of the opposite sex, without exclusivity. In most animal species, there is one dominant mating system; however, humans exhibit more flexibility. In humans, mating behavior is highly influenced by both biological and social factors. Humans also differ from animals by having formal relationships to correspond with mate choice. Mating may or may not be associated with these social relationships, such as marriage or dating.

Key Concept

Direct benefits provide advantages to the mate. Indirect benefits provide advantages to offspring.

Mate choice, or intersexual selection, is the selection of a mate based on attraction. Mate bias refers to how choosy members of the species are while choosing a mate. This bias is an evolutionary mechanism aimed at increasing the fitness of the species. It may carry direct benefits by providing material advantages, protection, or emotional support, or indirect benefits by promoting better survival in offspring.

There are five recognized mechanisms of mate choice:

· Phenotypic benefits: observable traits that make a potential mate more attractive to the opposite sex. Usually, these traits indicate increased production and survival of offspring. For example, males that appear more nurturing are more likely to care for, and promote the survival of, their offspring.

· Sensory bias: development of a trait to match a preexisting preference that exists in the population. For example, fiddler crabs are naturally attracted to structures that break up the level horizon because they may indicate a food source; male crabs take advantage of this fact by building pillars around their territory to attract mates.

· Fisherian or runaway selection: a positive feedback mechanism in which a particular trait that has no effect or a negative effect on survival becomes more and more exaggerated over time. In this model, a trait is deemed sexually desirable and thus is more likely to be passed on. This increases the attractiveness of the trait, which in turn increases the likelihood that it continues to be passed on. The bright plumage of the peacock, shown in Figure 10.4, is the prototypical example of Fisherian selection.

ImageFigure 10.4. Fisherian SelectionThe exaggerated plumage of the peacock is the prototypical example of Fisherian selection, in which the attractiveness of a trait that imparts a survival disadvantage leads to its continuation and exaggeration within the species.

· Indicator traits: traits that signify overall good health and well-being of an organism, increasing its attractiveness to mates. Notably, these traits may or may not be genetic in origin. For example, female cats are more attracted to male cats with clean and shiny coats; a dirty and dull coat may be related to an underlying genetic problem, or to malnutrition or infection.

· Genetic compatibility: the creation of mate pairs that, when combined, have complementary genetics. This theory provides a mechanism for the reduced frequency of recessive genetic disorders in the population: attraction to others who have starkly different genetic makeups reduces the probability of offspring being homozygotic for a disease-carrying allele.


Altruism is a form of helping behavior in which the individual’s intent is to benefit another at some cost to the self. Helping behavior can be motivated by selflessness, but can also be motivated by egoism or ulterior motives, such as public recognition. Empathy is the ability to vicariously experience the emotions of another, and it is thought by some social psychologists to be a strong influence on helping behavior. The empathy—altruism hypothesis is one explanation for the relationship between empathy and helping behavior. According to this theory, one individual helps another person when he or she feels empathy for the other person, regardless of the cost. This theory has been heavily debated, and more recent conceptions of altruism posit that an individual will help another person only when the benefits outweigh the costs for the individual.

Game Theory

Game theory attempts to explain decision-making behavior. The theory was originally used in economics and mathematics to predict interaction based on game characteristics, including strategy, winning and losing, rewards and punishments, and profits and cost. A game is defined by its players, the information and actions available to each player at decision points, and the payoffs associated with each outcome.

In the context of biology, game payoffs refer to fitness. Game theorists studying sex ratios in various species developed the concept of the evolutionary stable strategy (ESS). When an ESS is adopted by a given population in a specific environment, natural selection will prevent alternative strategies from arising. The strategies are thus inherited traits passed along with the population, with the object of the game being becoming more fit than competitors.

One of the classic evolutionary games is the Hawk—Dove game. The game focuses on access to shared food resources. In each round, a player chooses one of two strategies: hawk or dove. The hawk exhibits a fighter strategy, displaying aggression and fighting until he wins or is injured. The dove exhibits a fight avoidance strategy, displaying aggression at first but retreating if the fight escalates. If the dove is not faced with a fight, he will attempt to share the food resources. There are three potential outcomes. If two hawks compete, one will win and one will lose. If a hawk and a dove compete, the hawk will invariably win. If two doves compete, they will share the food resources. The payoff in this case is based on both the value of the reward and the cost of fighting: If the reward is significantly larger than the cost of fighting, then hawks have an advantage. If the cost of fighting is significantly larger, doves have an advantage. There thus exists an equilibrium point where, based on the magnitude of the reward and the cost of fighting, the hawk and dove strategies can coexist as evolutionary stable strategies.

The Hawk—Dove game represents pure competition between individuals. However, social influences apply in nature and can result in four possible alternatives for competitors when dealing with strategic interactions. The four alternatives are shown in Figure 10.5 and are:

· Altruism: the donor provides a benefit to the recipient at a cost to him- or herself

· Cooperation: both the donor and recipient benefit by cooperating

· Spite: both the donor and recipient are negatively impacted

· Selfishness: the donor benefits while the recipient is negatively impacted

ImageFigure 10.5. Strategic Alternatives for Socially Influenced Competitors

Other common strategy games, like rock—paper—scissors and chicken, can also be explained by game theory.

Inclusive Fitness

In evolutionary psychology, inclusive fitness is a measure of an organism’s success in the population. This is based on the number of offspring, success in supporting offspring, and the ability of the offspring to then support others. Early descriptions of evolutionary success were based solely on the number of viable offspring of an organism. However, contemporary theories take into account the benefits of certain behaviors on the population at large. For example, the existence of altruism could be supported by the observation that close relatives of an individual will share many of the same genes; thus, promoting the reproduction and survival of related or similar individuals can also lead to genetic success. Other species show examples of inclusive fitness by protecting the offspring of the group at large. By sacrificing themselves to protect the young, these organisms ensure the passing of genes to future generations. Inclusive fitness therefore promotes the idea that altruistic behavior can improve the fitness and success of a species as a whole.

Real World

Altruism creates a bit of a problem for the traditional Darwinist model of evolution. Why would an organism sacrifice its own fitness for the fitness of another? Evolutionary biologists still wrestle with this question, but inclusive fitness offers at least one potential solution.

MCAT Concept Check 10.1:

Before you move on, assess your understanding of the material with these questions.

1. What is interpersonal attraction, and what are three factors that influence this attraction?




2. For a behavior to be considered aggressive, is it necessary to have the intent to do harm? Does the behavior have to be physical in nature?

3. What are the four types of attachment? How does a child with each form of attachment act with regard to his or her caregiver?

Type of Attachment

Response to Caregiver

4. What is social support? List three of the common types of social support.




5. What is altruism?