MCAT Behavioral Sciences Review - Kaplan Test Prep 2021–2022


Absolute poverty—Poverty wherein people do not have enough resources to acquire basic life necessities such as shelter, food, clothing, and water.

Absolute threshold—The minimum stimulus energy needed to activate a sensory system.

Accommodation—Process by which existing schemata are modified to encompass new information.

Acetylcholine—A neurotransmitter associated with voluntary muscle control.

Achieved status—A status gained as a result of direct, individual action.

Acquisition—In classical conditioning, the process of taking advantage of reflexive responses to turn a neutral stimulus into a conditioned stimulus.

Actor-observer bias—The tendency to make situational attributions about the self, but dispositional attributions about others, regarding similar behaviors.

Adaptation—In perception, a decrease in stimulus perception after a long duration of exposure; in learning, the process by which new information is processed; consists of assimilation and accommodation.

Adaptive value—The extent to which a trait benefits a species by influencing the evolutionary fitness of the species.

Affect—The experience and display of emotion. Can be described as a scale, with both positive and negative affect having separate scales.

Afferent neuron—Sensory neurons which transmit information to the brain from the body in response to sensory input.

Ageism—Prejudice or discrimination on the basis of a person’s age.

Agent of Socialization—Any part of society that is important when learning social norms and values.

Aggression—A behavior with the intention to cause harm or increase relative social dominance; can be physical or verbal.

Agnosia—The loss of the ability to recognize objects, people, or sounds, though typically just one of the three.

Alcohol myopia—The inability to think about consequences and possible outcomes of one’s actions due to alcohol intoxication.

Alertness—State of consciousness in which one is aware, able to think, and able to respond to the environment; nearly synonymous with arousal.

Algorithm—A formula or procedure for solving a certain type of problem.

Aligning actions—An impression management strategy in which one makes questionable behavior acceptable through excuses.

Alter-casting—An impression management strategy in which one imposes an identity onto another person.

Altruism—A form of helping behavior in which the person’s intent is to benefit someone else at a cost to him- or herself.

Alzheimer’s disease—Degenerative brain disorder that is characterized by dementia and memory loss. Neurofibrillary tangles and β-amyloid plaques are phenomena found in the brains of Alzheimer’s patients.

Amphetamine—A central nervous system stimulant that increases activity of both dopamine and norepinephrine in the brain.

Amygdala—A portion of the limbic system that is important for memory and emotion, especially fear.

Anomie—A state of normlessness; anomic conditions erode social solidarity by means of excessive individualism, social inequality, and isolation.

Anterograde amnesia—Form of memory loss in which new long-term memories cannot be established.

Anxiety disorders—Disorders that involve worry, unease, fear, and apprehension about future uncertainties based on real or imagined events that can impair physical and psychological health.

Aphasia—Deficit of language production or comprehension.

Appraisal model—A similar theory to the basic model, accepting that there are biologically predetermined expressions once an emotion is experienced; accepts that there is a cognitive antecedent to emotional expression.

Archetype—In Jungian psychoanalysis, a thought or image that has an emotional element and is a part of the collective unconsciousness.

Arcuate fasciculus—A bundle of axons that connects Wernicke’s area (language comprehension) with Broca’s area (motor function of speech).

Arousal—A psychological and physiological state of being awake or reactive to stimuli; nearly synonymous with alertness.

Arousal theory—A theory of motivation that states there is a particular level of arousal required in order to perform actions optimally; summarized by the Yerkes—Dodson law.

Ascribed status—A status that one is given at birth, such as race, ethnicity, or sex.

Assimilation—In psychology, the process by which new information is interpreted in terms of existing schemata; in sociology, the process by which the behavior and culture of a group or an individual begins to merge with that of another group.

Associative learning—The process by which a connection is made between two stimuli or a stimulus and a response; examples include classical conditioning and operant conditioning.

Attachment—An emotional bond to another person, particularly a parent or caregiver. The four main attachment styles are: secure, avoidant, ambivalent, and disorganized.

Attitude—A tendency toward expression of positive or negative feelings or evaluations of a person, place, thing, or situation.

Attribute substitution—A phenomenon observed when individuals must make judgments that are complex but instead substitute a simpler solution or perception.

Attribution theory—A theory that focuses on the tendency for individuals to infer the causes of other people’s behavior.

Auditory cortex—Region of the temporal lobe devoted to sound processing.

Auditory pathway—After entering the brain, sound is processed by several regions, including the MGN, auditory cortex, superior olive, and inferior colliculus.

Authentic self—Who someone actually is, including both positive and negative attributes.

Automatic processing—The brain process most closely resembling autopilot, enabling performance of multiple activities at the same time.

Autonomic nervous system—The involuntary branch of the peripheral nervous system that controls involuntary functions such as heart rate, bronchial dilation, temperature, and digestion.

Autonomy—The ethical tenet that the physician has the responsibility to respect patients’ choices about their own healthcare.

Availability heuristic—A shortcut in decision making that relies on the information that is most readily available, rather than the total body of information on a subject.

Avoidance learning—A form of negative reinforcement in which one avoids the unpleasantness of something that has yet to happen.

Babbling—Precursor to language known to spontaneously occur in children.

Back stage—In the dramaturgical approach, the setting where players are free from their role requirements and not in front of the audience; back stage behaviors may not be deemed appropriate or acceptable and are thus kept invisible from the audience.

Barbiturate—A drug that acts as a central nervous system depressant; often used for anxiety, insomnia, and as an antiseizure medication.

Basal ganglia—A portion of the forebrain that coordinates muscle movement and routes information from the cortex to the brain and spinal cord.

Base-rate fallacy—Using prototypical or stereotypical factors while ignoring actual numerical information when making a decision.

Basic model—First established by Charles Darwin, a theory that states that emotional expression involves a number of systems: facial expression as well as behavioral and physical responses; claims that emotions are universal and should be similar across cultures.

Behaviorism—B. F. Skinner’s theory that all behaviors are conditioned. Behaviorism can be applied across many bodies of psychological thought, including theories of development, of identity, and of personality.

Belief—An acceptance that a statement is true or that something exists.

Belief perseverance—The inability to reject a particular belief despite clear evidence to the contrary.

Beneficence—The ethical tenet that the physician has a responsibility to act in the patient’s best interest.

Benzodiazepine—A central nervous system depressant that is often used to reduce anxiety or promote sleep.

Biomedical approach—An approach to psychological disorders that considers only pathophysiological causes and offers pharmaceutical and medical solutions for symptom alleviation.

Biopsychosocial approach—An approach to psychological disorders that considers conditions and treatments to be dependent on biological, psychological, and social causes. Treatment under this approach includes both direct and indirect therapy.

Bipolar disorders—Class of mood disorders characterized by both depression and mania.

Birth rate—The number of births per population in a period of time; usually the number of births per 1000 people per year.

Bisexual—A sexual orientation wherein individuals are attracted to members of both sexes.

Bottom-up processing—Object recognition by parallel processing and feature detection in response to sensory stimuli.

Brainstem—The most primitive portion of the brain, which includes the midbrain and hindbrain; controls the autonomic nervous system and communication between the spinal cord, cranial nerves, and brain.

Broca’s aphasia—Loss of the motor function of speech, resulting in intact understanding with an inability to correctly produce spoken language.

Broca’s area—A brain region located in the inferior frontal gyrus of the frontal lobe (usually in the left hemisphere); largely responsible for the motor function of speech.

Bureaucracy—A formal organization with the goal of performing complex tasks as efficiently as possible by dividing work among a number of bureaus.

Bystander effect—The observation that, when in a group, individuals are less likely to respond to a person in need.

Cannon—Bard theory—A theory of emotion that states that a stimulus is first received and is then simultaneously processed physiologically and cognitively, allowing for the conscious emotion to be experienced.

Cataplexy—Loss of muscle control with intrusion of REM sleep during waking hours, usually caused by an emotional trigger.

Catatonia—Disorganized motor behavior characterized by various unusual physical movements or stillness.

Central nervous system (CNS)—The portion of the nervous system composed of the brain and spinal cord.

Cerebellum—A portion of the hindbrain that maintains posture and balance and coordinates body movements.

Cerebral cortex—The outermost layer of the cerebrum, responsible for complex perceptual, behavioral, and cognitive processes.

Cerebrospinal fluid (CSF)—An aqueous solution in which the brain and spinal cord rest; produced by cells lining the ventricles of the brain.

Cerebrum—A portion of the brain that contains the cerebral cortex, limbic system, and basal ganglia.

Characteristic institution—The social structure or institution about which societies are organized.

Chemoreceptors—Sensory neurons that respond to chemical stimuli.

Choice shift—This term is analogous to group polarization, but describes the behavior change of the group as a whole rather than the individual.

Circadian rhythm—The alignment of physiological processes with the 24-hour day, including sleep—wake cycles and some elements of the endocrine system.

Circular reaction—A repetitive action that achieves a desired response; seen during Piaget’s sensorimotor stage.

Class consciousness—In Marxist theory, the organization of the working class around shared goals and recognition of a need for collective political action.

Classical conditioning—A form of associative learning in which a neutral stimulus becomes associated with an unconditioned stimulus such that the neutral stimulus alone produces the same response as the unconditioned stimulus; the neutral stimulus thus becomes a conditioned stimulus.

Cocaine—Drug that decreases reuptake of dopamine, norepinephrine, and serotonin, with effects similar to amphetamines.

Cognition—The process of acquiring knowledge and understanding through thought, experiences, and the senses; how we think and respond to the world.

Cognitive appraisal—The subjective evaluation of a situation that induces stress, consisting of both an initial primary appraisal and a potential secondary appraisal if a threat is revealed during primary appraisal.

Cognitive development—The development of one’s ability to think and solve problems across the life span.

Cognitive dissonance—The simultaneous presence of two opposing thoughts or opinions.

Cognitive reassociation model—A model of aggression which states that we are more likely to respond aggressively when experiencing negative emotions.

Collective unconscious—In Jungian psychoanalysis, the part of the unconscious mind that is shared among all humans and is a result of our common ancestry.

Colliculi—Two structures in the midbrain involved in sensorimotor reflexes; the superior colliculus receives visual sensory input, and the inferior colliculus receives auditory sensory input.

Compliance—A change of behavior of an individual at the request of another.

Concordance rates—In twin studies, the presence of a trait in both twins.

Conditioned response—In classical conditioning paradigms, the reflexive response caused by a conditioned stimulus.

Conditioned stimulus—In classical conditioning paradigms, this is an initially neutral stimulus that is paired with an unconditioned stimulus to train a behavioral response, rendering the previously neutral stimulus a conditioned stimulus.

Conduction aphasia—A speech disorder characterized by the inability to repeat words with intact spontaneous speech production and comprehension; usually due to injury to the arcuate fasciculus.

Confirmation bias—A cognitive bias in which one focuses on information that supports a given solution, belief, or hypothesis and ignores evidence against it.

Conflict theory—A theoretical framework that emphasizes the role of power differentials in producing social order.

Conformity—The changing of beliefs or behaviors in order to fit into a group or society.

Consciousness—Awareness of oneself; can be used to describe varying levels of awareness that occur with wakefulness, sleep, dreaming, and drug-induced states.

Conservation—Concept seen in quantitative analysis performed by a child; develops when a child is able to identify the difference between quantity by number and actual amount, especially when faced with identical quantities separated into varying pieces.

Constancy—In sensory perception, perceiving certain characteristics of object to remain the same despite differences in the environment.

Context effect—A retrieval cue by which memory is aided when a person is in the location where encoding took place.

Contralateral—On the opposite side of the body, relative to something else (usually a side of the brain).

Controlled (conscious) processing—Processing method used when a task requires complete attention.

Correspondent inference theory—A theory that states that people pay closer attention to intentional behavior than accidental behavior when making attributions, especially if the behavior is unexpected.

Cortical homunculus—A “map” that relates regions of the brain to the anatomical regions of the body.

Critical period—A time during development during which exposure to language is essential for eventual development of the effective use of language; occurs between two years of age and puberty.

Crystallized intelligence—Cognitive capacity to understand relationships or solve problems using information acquired during schooling and other experiences.

Cues—In understanding the behavior of others, indicators of the underlying cause of a behavior. This includes consistency cues, consensus cues, and difference cues.

Cultural capital—The benefits one receives from knowledge, abilities, and skills.

Cultural diffusion—The spread of norms, cultures, and beliefs throughout a culture.

Cultural relativism—The theory that social groups and cultures must be studied on their own terms to be understood.

Cultural sensitivity—Recognizing and respecting the differences between cultures.

Cultural syndrome—A shared set of beliefs, attitudes, norms, values, and behaviors organized around a central theme and found among people who speak the same language and share a geographic region.

Cultural transmission—The means by which a society socializes its members.

Culture—The beliefs, behaviors, actions, and characteristics of a group or society of people.

Culture shock—Cultural differences that are seen as quite dramatic when travelling outside of one's own society.

Deductive reasoning—A form of cognition that starts with general information and narrows down that information to create a conclusion.

Defense mechanism—In Freudian psychoanalysis, a technique used by the ego that denies, falsifies, or distorts reality in order to resolve anxiety caused by undesirable urges of the id and superego.

Deindividuation—The idea that people will lose a sense of self-awareness and can act dramatically differently based on the influence of a group.

Delirium—Rapid fluctuation in cognitive function that is reversible and has a nonpsychological cause.

Delusions—Fixed, false beliefs that are discordant with reality and not shared by one’s culture, and are maintained in spite of strong evidence to the contrary.

Dementia—Intellectual decline starting with impaired memory and progressing to impaired judgment and confusion.

Demographic shift—A change in the makeup of a population over time.

Demographic transition—The transition from high birth and mortality rates to lower birth and mortality rates, seen as a country develops from a preindustrial to an industrialized economic system.

Demographics—The statistical arm of sociology, which attempts to characterize and explain populations by quantitative analysis.

Depressant—Any substance that reduces nervous system function.

Depressive disorder—Sadness meeting certain conditions of severity and duration such that a diagnosis of a mental health issue is warranted. Depressive disorders include, among others: major depression, dysthymic disorder, and seasonal affective disorder.

Depressive episode—A period of at least two weeks in which there is a prominent and persistent depressed mood or lack of interest and at least four other depressive symptoms.

Deviance—The violation of norms, rules, or expectations within a society.

Diagnostic and Statistical Manual of Mental Disorders (DSM)—The guide by which most psychological disorders are characterized, described, and diagnosed; currently in its fifth edition (DSM-5, published May 2013).

Diencephalon—A portion of the prosencephalon that becomes the thalamus, hypothalamus, posterior pituitary gland, and pineal gland.

Differential association theory—Theory that deviance can be learned through interactions with others who engage in deviant behavior, provided those interactions outnumber interactions with those who conform to social norms in number and/or importance.

Disconfirmation principle—The idea that states that if evidence obtained during testing does not confirm a hypothesis, then the hypothesis is discarded or revised.

Discrimination—In classical conditioning, the process by which two similar but distinct conditioned stimuli produce different responses; in sociology, when individuals of a particular group are treated differently than others based on their group.

Discriminative stimulus—In behavioral conditioning, a stimulus whose presence indicates the opportunity for reward.

Dishabituation—A sudden increase in response to a stimulus, usually due to a change in the stimulus or addition of another stimulus; sometimes called resensitization.

Displacement—A defense mechanism by which undesired urges are transferred from one target to another, more acceptable one.

Display rules—Cultural expectations of how emotions can be expressed.

Dispositional (internal) attributions—Attributions that relate to the decisions or personality of the person whose behavior is being considered.

Dissociative disorders—Disorders that involve a perceived separation from identity or the environment.

Distal stimulus—Part of the outside world that serves as a source for stimuli that reach the sensory neurons.

Distant networks—Networks that are looser and composed of weaker ties.

Distress—The stress response to unpleasant stressors.

Divided attention—The ability to attend to multiple stimuli simultaneously and to perform multiple tasks at the same time.

Dizygotic twins—Fraternal twins who share approximately 50% of their genes, as with most siblings.

Dominant hemisphere—The side of the brain that provides analytic, language, logic, and math skills; in most individuals, the left hemisphere.

Dopamine—A neurotransmitter associated with smooth movements, steady posture, the reward pathway, and psychosis.

Dramaturgical approach—An impression management theory that represents the world as a stage and individuals as actors performing to an audience.

Dreaming—Phenomenon which mostly occurs during REM sleep. Theories proposed to explain this phenomenon include activation-synthesis theory, problem-solving dream theory, and cognitive process dream theory.

Drive reduction theory—A theory that explains motivation as being based on the goal of eliminating uncomfortable internal states.

Drives—Deficiencies that activate particular behaviors focused on a goal, which can be further subdivided into either primary (body-sustaining) or secondary (not biologically necessary) drives.

Dual-coding theory—A cognitive theory that states that both visual and verbal associations are used to encode and retrieve information.

Duplicity theory of vision—A theory which holds that the retina contains two types of specialized photoreceptors: rods specialized for light and dark perception and cones specialized for color perception.

Dyssomnia—A sleep disorder in which one has difficulty falling asleep, staying asleep, or avoiding sleep.

Ecstasy—Common name for MDMA (3,4-methylenedioxy-N-methylamphetamine); a central nervous system stimulant with effects similar to both amphetamines and hallucinogens.

Efferent neurons—Motor neurons that transmit information from the central nervous system to the periphery.

Ego—In Freudian psychoanalysis, the part of the unconscious mind that mediates the urges of the id and superego; operates under the reality principle.

Egocentrism—Self-centered view of the world in which one is not necessarily able to understand the experience of another person; seen in Piaget’s preoperational stage.

Elaboration likelihood model—A theory in which attitudes are formed and changed through different routes of information processing based on the degree of deep thought given to persuasive information. There are two possible processing routes within this model; central route processing (deep thinking or elaborative) and peripheral route processing (non-elaborative).

Elaborative rehearsal—The association of information in short-term memory to information already stored in long-term memory; aids in long-term storage.

Electroencephalography (EEG)—A test used to study the electrical patterns of the brain under varying conditions; consists of multiple electrodes placed on the scalp. Characteristic EEG patterns include beta, alpha, theta, and delta waves, as well as patterns associated with REM sleep.

Emotion—A feeling and state of mind derived from circumstances, mood, or relationships.

Emotional support—Listening to, affirming, and empathizing with someone’s feelings as part of social support.

Empathy—The ability to vicariously experience the emotions of another.

Empathy-altruism hypothesis—Theory that one individual helps another when they feel empathy for the other person.

Encoding—The process of receiving information and preparing it for storage; can be automatic or effortful.

Endorphins—Natural painkillers produced by the brain.

Epinephrine—A neurotransmitter associated with the fight-or-flight response.

Errors of growth—Misuse of grammar characterized by universal application of a rule, regardless of exceptions; seen in children during language development.

Escape learning—A form of negative reinforcement in which one reduces the unpleasantness of something that already exists.

Esteem support—Affirming qualities and skills of the person as part of social support.

Ethnic enclave—Locations with a high concentration of one specific ethnicity that can often slow assimilation

Ethnicity—A social construct that sorts people by cultural factors, including language, nationality, religion, and other factors.

Ethnocentrism—The practice of making judgments about other cultures based on the values and beliefs of one’s own culture.

Eustress—The stress response to positive conditions.

Evolutionary stable strategy—A strategy that, once adopted, will use natural selective pressure to prevent alternate strategies from arising.

Exchange theory—In social structure, an extension of rational choice theory that focuses on interactions in groups. Exchange theory holds that behavior is engaged in based on expectancy of future rewards and/or punishments.

Expectancy-value theory—The amount of motivation needed to reach a goal is the result of both expectation of success in reaching the goal and degree to which reaching the goal is valued.

Explicit memory—Memory that requires conscious recall, divided into facts (semantic memory) and experiences (episodic memory); also known as declarative memory.

Extinction—In classical conditioning, the decrease in response resulting from repeated presentation of the conditioned stimulus without the presence of the unconditioned stimulus.

Extrapyramidal system—Part of the basal ganglia that modulates motor activity.

Extraversion—In trait theory, the degree to which an individual is able to tolerate social interaction and stimulation.

Extrinsic motivation—Motivation that is external, or outside the self, including rewards and punishments.

False consciousness—In Marxist theory, a misperception of one's actual position within society.

Family group—A group determined by birth, adoption, and marriage rather than self-selection (as in a peer group).

Fertility rate—The average number of children born to a woman during her lifetime in a population.

Fisherian selection—Also called runaway selection, this is a positive feedback mechanism in which a trait with no impact (or a negative impact) on survival becomes more and more exaggerated over time, especially if the trait is deemed sexually desirable.

Fixation—In Freudian psychoanalysis, the result of overindulgence or frustration during a psychosexual stage causing a neurotic pattern of personality based on that stage.

Flat affect—Behavior characterized by showing virtually no signs of emotion or affective expression.

Fluid intelligence—Ability to quickly identify relationships and connections, and then use those relationships and connections to make correct deductions.

Foraging—The act of searching for and exploiting food resources.

Forebrain—A portion of the brain that is associated with complex perceptual, cognitive, and behavioral processes such as emotion and memory.

Fornix—A long projection from the hippocampus that connects to other nuclei in the limbic system.

Front stage—In the dramaturgical approach, the setting where players are in front of an audience and perform roles that are in keeping with the image they hope to project about themselves.

Frontal lobe—A portion of the cerebral cortex that includes the prefrontal cortex and the motor cortex; it controls motor processing, executive function, and the integration of cognitive and behavioral processes.

Functional attitudes theory—Theory that attitudes serve four functions: knowledge, ego expression, adaptation, and ego defense.

Functional fixedness—The inability to identify uses for an object beyond its usual purpose.

Functionalism—A theoretical framework that explains how parts of society fit together to create a cohesive whole, via both manifest (intended to help some part of the system) and latent (unintended positive) functions.

Fundamental attribution error—The general bias toward making dispositional attributions rather than situational attributions when analyzing another person’s behavior.

Game theory—A model that explains social interaction and decision making as a game, including strategies, incentives, and punishments.

γ-aminobutyric acid (GABA)—A neurotransmitter associated with stabilizing and quelling brain activity.

Ganglia—Collections of neuron cell bodies found outside the central nervous system.

—Theory that distinguishes between two major types of groups: communities (Gemeinschaft und GesellschaftGemeinschaften), which share beliefs, ancestry, or geography; and societies (Gesellschaften), which work together toward a common goal.

Gender—The set of behavioral, cultural, or psychological traits typically associated with a biological sex.

Gender inequality—The intentional or unintentional empowerment of one gender to the detriment of the other.

Gender segregation—The separation of individuals based on perceived gender.

General adaptation syndrome—Sequence of physiological responses developed by Selye in response to stress, initiating with alarm, followed by resistance, and finally exhaustion.

Generalization—In classical conditioning, the process by which two distinct but similar stimuli come to produce the same response.

Genotype—The genetic makeup of an individual.

Gentrification—The process of renewal of low income areas by upper-class populations, ultimately displacing the lower income residents.

Gestalt principles—Goverened by the law of prägnanz, ways for the brain to infer missing parts of a picture when a picture is incomplete.

Ghetto—An area where a specific religious, racial, or ethnic minority is concentrated, usually due to social or economic inequality.

Globalization—The process of integrating the global economy with free trade and tapping of foreign labor markets.

Glutamate—An excitatory neurotransmitter in the central nervous system.

Glycine—An inhibitory neurotransmitter in the central nervous system.

Group—A social entity that involves at least two people, usually those sharing common characteristics.

Group conformity—Compliance with a group’s goals, even when the group’s goals may be in direct contrast to an individual’s goals.

Group polarization—The tendency toward decisions that are more extreme than the individual inclinations of the group members.

Groupthink—The tendency for groups to make decisions based on ideas and solutions that arise within the group without considering outside ideas and ethics; based on pressure to conform and remain loyal to the group.

Gyrus—A ridge of the cerebral cortex.

Habituation—A decrease in response caused by repeated exposure to a stimulus.

Hallucinations—Perceptions that are not due to external stimuli but have a compelling sense of reality.

Hallucinogens—A group of drugs that cause distortions of reality in users, including lysergic acid diethylamide (LSD) and psilocybin-containing mushrooms.

Halo effect—A cognitive bias in which judgments of an individual’s character can be affected by the overall impression of the individual.

Heterosexual—A sexual orientation wherein individuals are attracted to members of the opposite sex.

Heuristic—A rule of thumb or shortcut that is used to make decisions.

Hidden curriculum—In education, the transmission to students of social norms, attitudes, and beliefs.

Hierarchy of salience—Theory of identity organization that posits that we let situations dictate which identity holds the most importance at any given moment.

Hindbrain—A portion of the brain that controls balance, motor coordination, breathing, digestion, and general arousal processes.

Hippocampus—A portion of the limbic system that is important for memory and learning.

Homosexual—A sexual orientation wherein individuals are attracted to members of the same sex.

Humanistic theory—The set of theories that hold that personality is the result of the conscious feelings we have for ourselves as we attempt to attain our needs and goals. The theories of Kelly, Maslow, Lewin, and others fall into this category.

Hypnagogic hallucinations—Hallucinations that occur when going to sleep; seen in narcolepsy.

Hypnopompic hallucinations—Hallucinations that occur when awakening from sleep; seen in narcolepsy.

Hypnosis—An altered state of consciousness in which a person appears to be awake but is, in fact, in a highly suggestible state in which another person or event may trigger action by the person.

Hypothalamus—A portion of the forebrain that controls homeostatic and endocrine functions by controlling the release of pituitary hormones.

Id—In Freudian psychoanalysis, the part of the unconscious resulting from basic, instinctual urges for sexuality and survival; operates under the pleasure principle and seeks instant gratification.

Ideal self—The person one would optimally like to be.

Identity—A piece of an individual’s self-concept based on the groups to which that person belongs and his or her relationships to others.

Identity shift effect—When an individual's state of harmony is disrupted by a threat of social rejection, the individual will often conform to the norms of the group, followed by a corresponding identity shift to reduce cognitive dissonance.

Immediate networks—Networks that are dense with strong ties; generally overlap with distant networks.

Implicit memory—Memory that does not require conscious recall; consists of skills and conditioned behaviors.

Implicit personality theory—A theory that states that people tend to associate traits and behavior in others, and that people have the tendency to attribute their own beliefs, opinions, and ideas onto others.

Impression management—Behaviors that are intended to influence the perceptions of other people about a person, object, or event.

Incentive—A reward intended to motivate particular behaviors.

Incentive theory—Theory that behavior is motivated by the desire to pursue rewards and avoid punishments.

Incidence—The number of new cases of a disease per population at risk in a given period of time; usually, new cases per 1000 at-risk people per year.

Inclusive fitness—A measure of reproductive success; depends on the number of offspring an individual has, how well they support their offspring, and how well their offspring can support others.

Individual discrimination—One person discriminating against a particular person or group.

Inductive reasoning—A form of cognition that utilizes generalizations to develop a theory.

Inferior colliculus—Region of the midbrain that receives and integrates sensory input from the auditory system, and is involved in reflexive reactions to auditory input.

Information processing model—Model of human cognition containing four key components: information intake, information analysis, situational modification, and content/complexity of problem.

Informational support—Support given by providing information to help another person.

Ingratiation—An impression management strategy that uses flattery to increase social acceptance.

In-group—A social group to which a person experiences a sense of belonging or one in which he or she identifies as a member.

Innate behavior—A behavior that is genetically programmed or instinctive.

Insomnia—Sleep disorder characterized by either an inability to fall asleep or difficulty staying asleep.

Instinct—An innate behavioral response to stimuli.

Instinct theory—In motivation, the theory that people are driven to engage in behaviors based on evolutionarily preprogrammed instincts.

Instinctive drift—The tendency of animals to resist learning when a conditioned behavior conflicts with the animal’s instinctive behaviors.

Institutional discrimination—Discrimination against a particular person or group by an entire institution.

Intelligence quotient—Numerical measurement of intelligence, usually accomplished by some form of standardized testing.

Interaction process analysis—A technique of observing and immediately classifying the activities of small groups.

Interference—A retrieval error caused by the learning of information; can be proactive (old information causes difficulty learning new information) or retroactive (new information interferes with older learning).

Internalization—Changing one's behavior to fit with a group while also privately agreeing with the ideas of the group.

Interneuron—A neuron found between sensory and motor neurons; involved in the reflex arc.

Interpersonal attraction—The force that makes people like each other.

Intersectionality—The interconnected nature of social categorizations as they apply to a given individual/group, especially when they lead to discrimination or oppression.

Intrinsic motivation—Motivation that is internal or that comes from within.

Intuition—Perceptions about a situation that may or may not be supported by available evidence, but are nonetheless perceived as information that may be used to make a decision.

Ipsilateral—On the same side of the body, relative to something else (usually a side of the brain).

Iron law of oligarchy—Democratic or bureaucratic systems naturally shift to being ruled by an elite group.

James—Lange theory—A theory of emotion that states that a stimulus results in physiological arousal, which then leads to a secondary response in which emotion is consciously experienced.

Justice—In medical ethics, the tenet that the physician has a responsibility to treat similar patients with similar care and to distribute healthcare resources fairly.

Just-noticeable difference (jnd)—The minimum difference in magnitude between two stimuli before one can perceive this difference; also called a difference threshold.

Just-world hypothesis—The cognitive bias that good things happen to good people, and bad things happen to bad people.

Labeling theory—Theory that labels given to people affect not only how others respond to that person, but also the person’s self-image.

Language—Spoken or written symbols (verbal and nonverbal symbols), which are regulated according to certain rules of conduct or social norms and used for communication.

Language acquisition device (LAD)—An innate capacity for language acquisition that is triggered by exposure to language; part of the nativist (biological) perspective of language acquisition.

Latent learning—Learning that occurs without a reward but that is spontaneously demonstrated once a reward is introduced.

Learned helplessness—A state of hopelessness and resignation resulting from being unable to avoid repeated negative stimuli; often used as a model of depression.

Learning—In psychology, the way in which new behaviors are acquired.

Learning (behaviorist) theory—A theory that attitudes are developed through forms of learning (direct contact, direct interaction, direct instruction, and conditioning).

Libido—In Freudian psychoanalysis, the sex or life drive.

Life course approach to health—An analysis of health and probable outcomes that includes consideration of the patient's entire history.

Limbic system—A portion of the cerebrum that is associated with emotion and memory and includes the amygdala and hippocampus.

Linguistic relativity hypothesis—A hypothesis suggesting that one’s perception of reality is largely determined by the content, form, and structure of language; also known as the Whorfian hypothesis.

Locus of control—The characterization of the source of influences on the events in one’s life; can be internal or external.

Long-term memory—The relatively limitless form of memory reserved for information that is sufficiently rehearsed or of sufficient impact. There are both implicit and explicit forms of long-term memory.

Long-term potentiation—The strengthening of neural connections due to rehearsal or relearning; thought to be the neurophysiological basis of long-term memory.

Looking-glass self—Social psychological construct stating that the self is developed through interpersonal reactions, specifically through a person’s understanding of the perception others have of them.

Magnocellular cells—In vision processing, cells that have high temporal resolution and detect motion.

Maintenance rehearsal—Repetition of a piece of information to either keep it within working memory or to store it.

Malthusian theory—Theory of demographic transition that focuses on how population growth can outpace food supply growth and lead to social degradation and disorder.

Managing appearances—An impression management strategy in which one uses props, appearance, emotional expression, or associations with others to create a positive image.

Manic episode—A period of at least one week with prominent and persistent elevated or expansive mood and at least two other manic symptoms.

Maslow’s heirarchy of needs—Abraham Maslow’s theory that certain needs will yield a greater influence on motivation. Maslow’s hierarchy consists of 5 “levels” of need.

Mass hysteria—A shared, intense concern about the threats to society.

Master status—A status with which a person is most identified.

Mate bias—A measure of how choosy members of a species are in choosing a mate, based upon both direct and indirect benefits of mate selection.

Mate choice—The intersexual selection of a mate based on attraction and traits.

Material culture—The physical items one associates with a given cultural group.

Material support—Providing economic or other physical resources to aid a person as part of social support.

Mating system—The way in which a group organizes its sexual behavior and sexual relationships.

McDonaldization—A shift in focus toward efficiency, predictability, calculability, and control in societies.

Meditation—A state of consciousness entered voluntarily, characterized by a decreased level of physiological arousal and a quieting of the mind.

Medulla oblongata—A portion of the brainstem that regulates vital functions, including breathing, heart rate, and blood pressure.

Melatonin—A serotonin derivative secreted by the pineal gland that is associated with sleepiness.

Meninges—A thick layer of connective tissue that covers and protects the brain; composed of the dura mater, arachnoid mater, and pia mater.

Mental set—A tendency to repeat solutions that have yielded positive results at some time in the past.

Mere exposure effect—An explanation of attraction, also called the familiarity effect, which holds that people prefer stimuli that they have been exposed to more frequently.

Meritocracy—A society in which advancement up the social ladder is based on intellectual talent and achievement.

Mesencephalon—The embryonic portion of the brain that becomes the midbrain.

Mesolimbic reward pathway—Dopaminergic pathway in the brain including the nucleus accumbens, ventral tegmental area, and the medial forebrain bundle. This pathway is normally involved in motivation and emotional response, and is involved in drug addiction.

Metencephalon—The embryonic portion of the brain that becomes the pons and cerebellum.

Midbrain—A portion of the brainstem that manages sensorimotor reflexes to visual and auditory stimuli and gives rise to some cranial nerves.

Migration—The movement of people from one population to another, including immigration and emigration.

Mirror neurons—Neurons located in the frontal and parietal lobes and which fire both when an individual performs an action and when an individual sees that action performed.

Misinformation effect—A phenomenon in which memories are altered by misleading information provided at the point of encoding or recall.

Mnemonic—A technique that aids in memory recall.

Monogamy—An exclusive mating relationship.

Monozygotic twins—Identical twins, sharing the same genetic material.

Mood disorder—A mental health diagnosis category containing disorders primarily characterized by disturbance in mood. This includes depressive disorders, substance-induced, and bipolar disorders.

Moral reasoning—Kohlberg’s theory of personality evelopment, which is focused on the development of moral thinking through preconventional, conventional, and postconventional stages.

Morbidity—The burden or degree of illness associated with a given disease.

Morphology—The structure of words, including their building blocks (prefixes, suffixes, and so on).

Mortality rate—The number of deaths in a population per unit time.

Motivation—The process of psychological and physical requirements, goals, or desires causing behavior.

Motor neuron—A neuron that transmits motor information from the spinal cord and brain to the periphery.

Multiculturalism—The encouragement of multiple cultures in a society to enhance diversity. Also referred to as cultural diversity.

Multiple intelligences—The idea that intelligence may exist in multiple areas, not just in the areas typically assessed by traditional intelligence quotient tests.

Myelencephalon—The embryonic portion of the brain that becomes the medulla oblongata.

Narcolepsy—A sleep disorder characterized by a lack of voluntary control over the onset of sleep; also involves cataplexy and hypnagogic and hypnopompic hallucinations.

Nativist theory (of language)—Theory credited to Noam Chomsky that posits the existence of an innate capacity for language, referred to as the language acquisition device.

Needs—Physiological and psychological requirements that motivate and influence behavior.

Negative symptoms—In mental illness, symptoms characterized by the absence of normal or desired behaviors.

Neologism—Coining a new word; seen in schizophrenia.

Network—A term used to describe the observable pattern of social relationships among individual units of analysis.

Network redundancy—Overlapping contact points within a social network.

Network support—Providing a sense of belonging as part of social support.

Neurocognitive models of dreaming—Models of dreaming that correlate subjective, cognitive experiences of dreaming with measurable physiological changes.

Neuroleptics (antipsychotics)—A class of drugs used to treat schizophrenia by blocking dopamine receptors

Neuromodulator—Peptides that act as signaling molecules in the central nervous system; they are slower to act and longer lasting than neurotransmitters.

Neuroplasticity—Change in neural connections caused by learning or a response to injury.

Neuropsychology—The study of functions and behaviors associated with specific regions of the brain.

Neurosis—In Freudian theory, a disorder that occurs in response to the anxiety of a fixation during childhood that impacts personality development,

Neuroticism—In trait theory, the degree to which an individual is prone to emotional arousal in stressful situations.

Neurotransmitter—A chemical that transmits signals from a neuron to a target cell across a synapse.

Neurulation—Stage in development in which the ectoderm furrows over the notochord, forming the neural crest and neural tube.

Night terror—An experience of intense anxiety during sleep, causing the sleeper to scream in terror with no recall of the event in the morning; occurs during slow-wave sleep.

Nondominant hemisphere—The side of the brain associated with sensitivity to the emotional tone of language, intuition, creativity, music, and spatial processing; in most individuals, the right hemisphere.

Nonmaleficence—The ethical tenet that the physician has a responsibility to avoid interventions in which the potential for harm outweighs the potential for benefit.

Non-rapid eye movement (NREM) sleep—Stages 1 through 4 of sleep; contains ever-slowing brain waves as one gets deeper into sleep.

Nonverbal communication—How people communicate, intentionally or unintentionally, without using words; examples include body language, gestures, and facial expressions.

Norepinephrine—A neurotransmitter associated with wakefulness and alertness.

Norms—Societal rules that define the boundaries of acceptable behavior.

Obedience—The changing of behavior of an individual based on a command from someone seen as an authority figure.

Object permanence—Knowledge that an object does not cease to exist even when the object cannot be seen; a milestone in cognitive development.

Observational learning—A form of learning in which behavior is modified as a result of watching others.

Obsessive—compulsive disorders—This category, which also includes related disorders, describes the set of disorders where people feel the need to check things repeatedly or have certain thoughts repeatedly, without the ability to control these thoughts or activities.

Occipital lobe—A portion of the cerebral cortex that controls visual processing.

Operant conditioning—A form of associative learning in which the frequency of a behavior is modified using reinforcement or punishment.

Opiates—A drug family consisting of naturally occurring, highly addictive, pain-reducing drugs used in both medical and recreational settings; opioids are synthetic versions of these drugs.

Opponent-process theory—A theory that states that the body will adapt to counteract repeated exposure to stimuli, such as seeing afterimages or ramping up the sympathetic nervous system in response to a depressant.

Organization—A specific type of group characterized by five traits: formality, hierarchy of ranked positions, large size, complex division of labor, and continuity beyond its members.

Ought self—The representation of the way others think one should be.

Out-group—A social group with which an individual does not identify.

Overconfidence—A tendency to interpret one’s decisions, knowledge, or beliefs as infallible.

Parallel play—Play style in which children can play alongside each other without interfering in each other’s behavior.

Parallel processing—The ability to simultaneously analyze and combine information regarding multiple aspects of a stimulus, such as color, shape, and motion.

Parasomnia—A sleep disorder characterized by abnormal movements or behaviors during sleep.

Parasympathetic nervous system—A branch of the autonomic nervous system that promotes resting and digesting; associated with relaxed states, reductions in heart and respiration rates, and promotion of digestion.

Parietal lobe—A portion of the cerebral cortex that controls somatosensory and spatial processing.

Parkinson’s disease—A disease characterized by slowness in movement, resting tremor, pill-rolling tremor, masklike facies, cogwheel rigidity, and a shuffling gait; caused by destruction of dopaminergic neurons in the substantia nigra.

Parvocellular cells—In visual processing, cells which have very high spatial resolution and detect shape.

Peer group—A group of self-selected equals that forms around common interests, ideas, preferences, and beliefs.

Peer pressure—The social influence placed on an individual by other individuals who are considered equals.

Perception—Processing of incoming information to comprehend and respond to the current incoming stimuli.

Peripheral nervous system (PNS)—The portion of the nervous system composed of nerve tissue and fibers outside the central nervous system.

Personality—The set of thoughts, feelings, traits, and behaviors that are characteristic of an individual across time and different locations.

Personality disorders—Disorders that involve patterns of behavior that are inflexible and maladaptive, causing distress or impaired function in at least two of the following: cognition, emotion, interpersonal functioning, or impulse control.

Phenotype—The expressed traits of an individual based on their genotype.

Phoneme—Individual speech sound associated with a language.

Phonology—The set of sounds that compose a language.

Piaget’s theory—Piaget’s theory of cognitive development divided the life span into sensorimotor, preoperational, concrete operational, and formal operational stages.

Pineal gland—A brain structure located near the thalamus that secretes melatonin.

Pituitary gland—The “master gland” of the endocrine system that triggers hormone release in other endocrine glands.

Place theory—Theory of sound conduction in the ear that holds that vibration on particular areas of the basilar membrane determines perception of pitch, also referred to as tonotopical organization.

Polyandry—A mating system in which a female has exclusive relationships with several males.

Polygamy—A mating system in which one member of a sex has multiple exclusive opposite-sex relationships.

Polygyny—A mating system in which a male has exclusive relationships with several females.

Pons—A portion of the brainstem that relays information between the cortex and medulla, regulates sleep, and carries some motor and sensory information from the face and neck.

Positive symptoms—Behaviors, thoughts, or feelings added to normal behavior.

Poverty—A socioeconomic condition of low resource availability; in the United States, the poverty line is determined by the government’s calculation of the minimum income requirements for families to acquire the minimum necessities of life.

Power—The capacity to influence people through the real or threatened use of rewards and punishments; often based on unequal distribution of valued resources.

Pragmatics—The ways in which use of language can be altered, depending on social context.

Prejudice—An irrational positive or negative attitude toward a person, group, or thing, formed prior to actual experience.

Prestige—In sociology, the amount of positive regard society has for a given person or idea.

Prevalence—The number of cases of a disease per population in a given period of time; usually, cases per 1000 people per year.

Primacy effect—The phenomenon of first impressions of a person being more important than subsequent impressions.

Primary group—A group wherein the interactions are direct, with close bonds, providing relationships to members that are very warm, personal, and intimate.

Primary stress appraisal—An initial evaluation of the environment to determine if there is an associated threat.

Priming—A retrieval cue by which recall is aided by a word or phrase that is semantically related to the desired memory.

Primitive reflexes—Reflexes present in infants that disappear with age.

Prodromal phase—A phase of poor adjustment that precedes the full onset of schizophrenia.

Projection—A defense mechanism by which individuals attribute their undesired feelings to others.

Projection area—A portion of the cerebral cortex that analyzes sensory input.

Promiscuity—A mating system in which a member of one sex mates with any member of the opposite sex.

Proprioception—The ability to tell where one’s body is in space.

Prosencephalon—The embryonic portion of the brain that becomes the forebrain.

Prosody—The rhythm, cadence, and inflection of speech.

Prospective memory—Remembering to perform a task at some point in a future.

Proximal stimulus—A stimulus that directly interacts with and affects sensory receptors.

Proximity—An aspect of interpersonal attraction based on being physically close to someone.

Psychoanalytic theory—In personality theory, the set of theories based on the assumption that unconscious internal states motivate overt actions and determine personality. The theories of several psychologists, including both Freud and Jung, fall into this category.

Psychological disorder—A set of thoughts, feelings, or actions that are considered deviant by the culture at hand and that cause noticeable distress to the sufferer.

Psychophysics—The study of the relationship between the physical nature of stimuli and the sensations/perceptions they evoke.

Psychosocial development—Erikson’s theory of personality development, which is based in the concept that personality is developed based on a series of crises deriving from conflicts between needs and social demands.

Psychoticism—In trait theory, the measure of nonconformity or social deviance of an individual.

Punishment—In operant conditioning, the use of an aversive stimulus designed to decrease the frequency of an undesired behavior.

Race—A social construct based on phenotypic differences between groups of people; these may be either real or perceived differences.

Racial formation theory—Theory that racial identity is fluid and dependent on political, economic, and social factors.

Racialization—The definition or establishment of a group as a particular race.

Rapid eye movement (REM) sleep—Sleep stage in which the eyes move rapidly back and forth and physiological arousal levels are more similar to wakefulness than sleep; dreaming occurs during this stage.

Rational choice theory—In social structure, the theory that individuals consider benefits and harms to themselves in any given social interaction and choose the best possible action.

Rationalization—A defense mechanism by which individuals explain undesirable behaviors in a way that is self-justifying and socially acceptable.

Reaction formation—A defense mechanism by which individuals suppress urges by unconsciously converting them into their exact opposites.

Reappraisal—Process for ongoing monitoring of a continuing source of stress that cannot be dealt with via the normal 2-step appraisal method.

Recency effect—The phenomenon in which the most recent information we have about an individual is most important in forming our impressions.

Reciprocal determinism—In the social cognitive perspective, the notion that thoughts, feelings, behaviors, and environment interact to determine behavior in a given situation.

Reciprocal liking—The phenomenon whereby people like others better when they believe the other person likes them.

Reciprocity—An aspect of interpersonal attraction based on the idea that we like people who we think like us.

Recognition-primed decision model—A decision-making model in which experience and recognition of similar situations one has already experienced play a large role in decision making and actions; also one of the explanations for the experience of intuition.

Reference group—The group to which an individual compares him- or herself for a given identity.

Reflex—A behavior that occurs in response to a given stimulus without higher cognitive input.

Reflex arc—A neural pathway that controls reflex actions.

Regional cerebral blood flow (rCBF)—A technique used to record patterns of neural activity based on blood flow to different areas of the brain measured using detection of inhaled radioactive markers.

Regression—A defense mechanism by which an individual deals with stress by reverting to an earlier developmental state.

Reinforcement—In operant conditioning, the use of a stimulus designed to increase the frequency of a desired behavior.

Reinforcement schedule—The schedule by which reinforcement is administered for behavior in operant conditioning; reinforcmeent schedules can be fixed or variable, and can be based on a ratio or an interval between rewards.

Relative poverty—Poverty wherein one is poor in comparison to the larger population.

Reliance on central traits—The tendency to organize the perception of others based on traits and personal characteristics of the target that matter to the perceiver.

REM rebound—Phenomenon in which one spends an increased time in REM sleep following a period of sleep deprivation.

Representativeness heuristic—A shortcut in decision making that relies on categorizing items on the basis of whether they fit the prototypical, stereotypical, or representative image of the category.

Repression—A defense mechanism by which the ego forces undesired thoughts and urges to the unconscious mind.

Response bias—The tendency of subjects to respond systematically to a stimulus in a particular way due to nonsensory factors.

Reticular formation—A structure in the brainstem that is responsible for alertness.

Retrieval—The process of demonstrating that information has been retained in memory; includes recall, recognition, and relearning.

Retrograde amnesia—A form of memory loss that impacts long-term memories of events prior to the time of injury.

Rhombencephalon—The embryonic portion of the brain that becomes the hindbrain.

Ritual—A formalized ceremony that usually involves specific material objects, symbolism, and additional mandates on acceptable behavior.

Role—A set of beliefs, values, attitudes, and norms that define expectations for behavior associated with a given status.

Role conflict—A difficulty in satisfying role requirements or expectations among various roles.

Role engulfment—Internalizing a label and assuming the role implied by the label leads to the assumed role taking over a person’s identity.

Role partner—The person with whom one interacts while playing a particular role; each role partner provides a different set of behavioral expectations.

Role performance—Carrying out the behaviors associated with a given role.

Role set—A group of role partners relative to a given status.

Role strain—Difficulty in satisfying multiple requirements of the same role.

Role-taking—Roleplaying, by which children come to understand the perspectives of others and the ways in which these perspectives may differ from their own.

Sanction—A societally enforced punishment or reward for behavior. Formal sanctions are those enforced by social institutions (laws), and informal sanctions are enforced by social behaviors (ostracization, etc.).

Schachter—Singer theory—A theory of emotion that states that both physiological arousal and cognitive appraisal must occur before an emotion is consciously experienced.

Schema—An organized pattern of thought and behavior; one of the central concepts of Piaget’s stages of cognitive development.

Schizophrenia—A psychotic disorder characterized by gross distortions of reality and disturbances in the content and form of thought, perception, and behavior.

Second sickness—The concept proposed by Howard Waitzkin that poor health outcomes are exacerbated by social injustice.

Secondary group—Groups wherein interactions are based on weaker, impersonal bonds.

Secondary stress appraisal—The interpretation of primary stress appraisal to determine emotional response to a given threat.

Selective attention—The ability to focus on a single stimulus even while other stimuli are occurring simultaneously.

Self-concept—The sum of the thoughts and feelings about oneself; includes self-schemata and appraisal of one’s past and future self.

Self-determination theory—Need-based motivational theory that emphasizes the importance of autonomy, competence, and relatedness.

Self-disclosure—An aspect of interpersonal attraction or impression management in which one shares his or her fears, thoughts, and goals with another person in the hopes of being met with empathy and nonjudgment.

Self-discrepancy theory—Theory that each of us has three selves: the actual self, the ideal self, and the ought self.

Self-efficacy—The degree to which an individual sees him- or herself as being capable at a given skill or in a particular situation.

Self-enhancement—In self-serving bias, the need to maintain self worth through internal attribution of success and external attribution of failure.

Self-esteem—An individual’s feelings of self-worth.

Self-fulfilling prophecy—The phenomenon of a stereotype creating an expectation of a particular group, which creates conditions that lead to confirmation of this stereotype.

Self-handicapping—An impression management strategy wherein one creates obstacles to avoid self-blame when he or she does not meet expectations.

Self-presentation—The process of displaying oneself to society through culturally accepted actions and behaviors.

Self-reference effect—The tendency for individuals to best recall information that they can relate to their own experiences.

Self-schema—A self-given label that carries with it a set of qualities.

Self-serving bias—The idea that individuals will view their own success as being based on internal factors, while viewing failures as being based on external factors.

Semantic network—Organization of information in the brain by linking concepts with similar characteristics and meaning.

Semantics—The association of meaning with a word.

Sensation—Transduction of physical stimuli into neurologic signals.

Sensitive period—A time during which environmental input has a maximal impact on the development of a particular ability.

Sensory memory—Visual (iconic) and auditory (echoic) stimuli briefly stored in memory; fades very quickly unless attention is paid to the information.

Sensory neuron—A neuron that transmits information from sensory receptors to the central nervous system.

Septal nuclei—Part of the limbic system and one of the pleasure centers of the brain.

Serial position effect—The tendency to better remember items presented at the beginning or end of a list; related to the primacy and recency effects.

Serotonin—A neurotransmitter associated with mood, sleep, eating, and dreaming.

Sexual orientation—The direction of one’s sexual interest toward members of the same, opposite, or both sexes.

Shadowing—An experimental technique in which participants recite speech immediately after hearing it.

Shaping—In operant conditioning, the process of conditioning a complicated behavior by rewarding successive approximations of the behavior.

Short-term memory—Memory which fades quickly, over about 30 seconds without rehearsal, and which is limited in capacity by the 7 ± 2 rule.

Sick role—Theory that a person who is ill enters a role of “sanctioned deviance”, in which they are not responsible for the illness and are exempt from social norms.

Signal detection theory—A theory of perception in which internal (psychological) and external (environmental) context both play a role in the perception of stimuli.

Similarity—An aspect of interpersonal attraction based on being alike in attitudes, intelligence, education, height, age, religion, appearance, or socioeconomic status.

Situational (external) attributions—Attributions that relate to features of the surroundings, such as threats, money, social norms, and peer pressure, rather than to features of the individual.

Sleep apnea—Sleep disorder in which a person may cease to breathe while sleeping; may be due to obstruction or a central (neurological) cause.

Sleep cycle—A single complete progression through each stage of sleep.

Slow-wave sleep—Consists of NREM sleep stages 3 and 4; also called delta-wave sleep.

Social action—Actions and behaviors that individuals are conscious of and performing because others are around.

Social capital—The investment people make in their society in return for economic or collective rewards.

Social class—A category of people with a shared socioeconomic background that exhibit similar lifestyles, job opportunities, attitudes, and behaviors.

Social cognitive theory—A theory that attitudes are formed through observation of behavior, cognition, and the environment.

Social construction model—A theory of emotional expression that assumes there are no biologically wired emotions; rather, they are based on experiences and situational context alone.

Social constructionism—A theoretical approach that uncovers the ways in which individuals and groups participate in the formation of their perceived social reality.

Social control—Regulating the behavior of individuals and groups within a society.

Social exclusion—The sense of being separated from and powerless in society when impoverished.

Social facilitation—The tendency of people to perform at a different level based on the fact that others are around.

Social institutions—Well-established, structured patterns of behavior or relationships that are accepted as a fundamental part of a culture.

Social interaction—The ways in which two or more individuals can shape each other’s behavior.

Social interactionist theory—In language development, the theory that language acquisition is driven by the desire to communicate. This theory includes both biological and social processes.

Social loafing—The tendency of individuals to put in less effort in group settings as compared to an individual setting.

Social mobility—The movement of individuals in the social hierarchy through changes in income, education, or occupation.

Social movements—Philosophies that drive large numbers of people to organize to promote or resist social change.

Social perception—Understanding the thoughts and motives of other people present in the social world; also referred to as social cognition.

Social reproduction—The concept that social inequality, especially poverty, can be reproduced and passed on from one generation to the next.

Social stratification—Organization of societies into a hierarchical system, usually based on socioeconomic status and social class.

Social structure—A system of people within a society organized by a characteristic pattern of relationships.

Social support—The perception or reality that one is cared for by a social network.

Socialization—The process of developing and spreading norms, customs, and beliefs.

Socioeconomic Status—Social standing or class of an individual or group, determined as a combination of education, income, and occupation.

Sociology—The study of society, including how it is created, interacted with, defined, and institutionalized.

Somatic nervous system—The voluntary branch of the peripheral nervous system, which consists of sensory and motor neurons used to control bodily movements.

Somatic symptom disorders—Mental health disorders marked by bodily symptoms that cause significant stress or impairment. This category of disorder also includes related disorders, such as illness anxiety and conversion disorders.

Somatosensation—The sense of touch, which contains multiple modalities: pressure, vibration, pain, and temperature.

Somatosensory cortex—Region of the parietal lobe located on the postcentral gyrus and involved in somatosensory information processing.

Somnambulism—Sleep disorder in which one carries out actions in his or her sleep; also called sleepwalking.

Source-monitoring error—A memory error by which a person remembers the details of an event but confuses the context by which the details were gained; often causes a person to remember events that happened to someone else as having happened to him- or herself.

Spacing effect—The phenomenon of retaining larger amounts of information when the amount of time between sessions of relearning is increased.

Spatial inequality—A form of social stratification across territories and their populations that can involve residential, environmental, or global components.

Spontaneous recovery—The reappearance of a conditioned response previously determined to be extinct.

Spreading activation—The unconscious activation of closely linked nodes of a semantic network.

State-dependent memory—A retrieval cue by which memory is aided when a person is in the same state of emotion or intoxication as when encoding took place.

Status—A position in society used to classify individuals.

Stereocilia—Structures on hair cells in the ear that sway with the movement of endolymph, causing receptor potential in the hair cells and ultimately leading to detection of incoming sound.

Stereotype content model—A model that classifies stereotypes using two dimensions: warmth and competence.

Stereotype threat—A feeling of anxiety about confirming a negative stereotype about one’s social group.

Stereotypes—Attitudes and impressions that are made based on limited and superficial information about a person or a group of individuals.

Stigma—The extreme disapproval or dislike of a person or group based on perceived differences in social characteristics from the rest of society.

Stimulant—A drug that causes an increase in central nervous system arousal.

Stimulus—Any energy pattern that is sensed in some way by the body; includes visual, auditory, and physical sensations, among others.

Storage—The retention of encoded information; divided into sensory, short-term, and long-term memory.

Strain theory—Theory that explains deviance as a natural reaction to the disconnect between social goals and social structure.

Stress—The response to significant events, challenges, and decisions.

Stressors—Biological elements, external conditions, or events that lead to a stress response.

Structural poverty—Theory that poverty is due to inadequacies in societal and economic structure.

Subcultures—Groups of people within a culture that distinguish themselves from the primary culture to which they belong.

Sublimation—A defense mechanism by which unacceptable urges are transformed into socially acceptable behaviors.

Subliminal perception—Perception of a stimulus below a threshold (usually the threshold of conscious perception).

Substantia nigra—Part of the basal ganglia responsible for dopamine release that permits proper functioning of the rest of the basal ganglia.

Sulcus—A fold in the cerebral cortex.

Superego—In Freudian psychoanalysis, the part of the unconscious mind focused on idealism, perfectionism, and societal norms.

Superior colliculus—Structure in the midbrain that receives visual input and impacts eye movements and object oriented behaviors.

Symbolic culture—The nonmaterial culture that represents a group of people; expressed through ideas and concepts.

Symbolic ethnicity—An ethnic identity that is only relevant on special occasions or in specific circumstances and that does not impact everyday life.

Symbolic interactionism—A theoretical framework that studies the way individuals interact through a shared understanding of words, gestures, and other symbols.

Sympathetic nervous system—The branch of the autonomic nervous system that controls the fight-or-flight response; associated with stressful situations that increase heart and respiration rates and decrease digestion.

Synaptic pruning—Adjustment of neural connections throughout life, involving breaking of weak neural connections and bolstering of strong neural connections.

Syntax—The way in which words are organized to create meaning.

System for multiple level observation of groups (SYMLOG)—A method of studying group dynamics; focuses on three fundamental dimensions of interaction: dominance vs. submission, friendliness vs. unfriendliness, and instrumentally controlled vs. emotionally expressive.

Tactical self—In impression management, the person one markets him- or herself to be when adhering to others’ expectations.

Telencephalon—A portion of the prosencephalon that becomes the cerebrum.

Temporal lobe—A portion of the cerebral cortex that controls auditory processing, memory processing, emotional control, and language.

Tetrahydrocannabinol (THC)—The main active ingredient in marijuana.

Thalamus—A portion of the forebrain that serves as a relay and sorting station for sensory information, and then transmits the information to the cerebral cortex.

Theory of mind—The ability to sense how another’s mind works.

Threshold—Also called limina; the minimum amount of a stimulus that renders a difference in perception.

Tolerance—Decreased response to a drug after physiological adaptation.

Top-down processing—Object recognition driven by memories and expectations that allow the brain to first recognize the whole object, and then recognize components based on existing expectations.

Trait theory—Personality theory that is focused on describing individual personalities as the sum of characteristic behaviors.

Transduction—Conversion of physical, electromagnetic, auditory, and other stimuli to electrical signals in the nervous system.

Transformational grammar—A linguistic theory that focuses on how changes in word order affect meaning.

Two-point threshold—The minimum distance necessary between two points of stimulation on the skin such that the points will be felt as two distinct stimuli.

Type theory—Theorifes of personality that are focused on creating taxonomies, or finite lists, of personality types.

Unconditioned response—In classical conditioning paradigms, the innate response brought about by an unconditioned stimulus prior to any conditioning.

Unconditioned stimulus—In classical conditioning paradigms, a stimulus that brings about an innate response.

Universal emotions—Emotions that are recognized by all cultures; include happiness, sadness, contempt, surprise, fear, disgust, and anger.

Urbanization—The process whereby large numbers of people migrate to and establish residence in relatively dense areas of population.

Value—What one deems important in life.

Ventricle—An internal cavity within the brain; cells lining the ventricles produce cerebrospinal fluid.

Verbal communication—The use of spoken or signed language.

Vestibular sense—One of the functions of the ear, the detection of rotational and linear acceleration to maintain awareness of body rotation and movement.

Visual cortex—Region of the occipital lobe devoted to processing visual information.

Visual pathways—Term which refers to both anatomical connections between eyes and brain and the flow of information from eyes to brain. The visual pathway contains several brain regions including the LGN, the visual cortex, and the superior colliculus.

Vygotsky theory—In cognitive development, the theory that the engine driving cognitive development is childhood internalization of culture.

Weber’s law—A theory of perception that states that there is a constant ratio between the change in stimulus magnitude needed to produce a just noticeable difference and the magnitude of the original stimulus.

Wernicke—Korsakoff Syndrome—A condition resulting from chronic thiamine (vitamin B1) deficiency, which is common in alcoholics; characterized by severe memory impairment with changes in mental status and loss of coordination.

Wernicke’s aphasia—Loss of language comprehension, resulting in fluid production of language without meaning.

Wernicke’s area—A brain region located in the superior temporal gyrus of the temporal lobe (usually in the left hemisphere); largely responsible for language comprehension.

Working memory—Form of memory that allows limited amounts of information in short-term memory to be manipulated.

World system theory—World system theory argues there are global level inequalities in the division of labor between core, semi-peripheral, and peripheral nations.

Yerkes-Dodson law—A theory that there is a U shaped function relating arousal level and performance, dictating that performance is worst at the extreme high and low ends of arousal and optimal at intermediate arousal levels. This law is the basis of the Yerkes-Dodson law of social facilitation, a specific application of the Yerkes-Dodson law.

Zone of proximal development—Those skills that a child has not yet mastered but can accomplish with the help of a more knowledgeable other.