G-1

GLOSSARY

A

absolute threshold The smallest possible strength of a stimulus that can be detected half the time. (p. 88)

accommodation The process by which the lens changes shape to focus incoming light so that it falls on the retina. (p. 91)

acculturative stress (uh-CUL-chur-uh-tiv) The stress that results from the pressure of adapting to a new culture. (p. 507)

acetylcholine (uh-seet-ull-KO-leen) Neurotransmitter that causes muscle contractions and is involved in learning and memory. (p. 49)

achievement motivation The desire to direct your behavior toward excelling, succeeding, or outperforming others at some task. (p. 334)

achievement test A test designed to measure a person’s level of knowledge, skill, or accomplishment in a particular area. (p. 294)

action potential A brief electrical impulse by which information is transmitted along the axon of a neuron. (p. 44)

activation-synthesis model of dreaming The theory that brain activity during sleep produces dream images (activation), which are combined by the brain into a dream story (synthesis). (p. 150)

activity theory of aging The psychosocial theory that life satisfaction in late adulthood is highest when people maintain the level of activity they displayed earlier in life. (p. 405)

actor-observer bias The tendency to attribute our own behavior to external, situational characteristics, while ignoring or underestimating the effects of internal, personal factors. (p. 459)

actualizing tendency In Rogers’s theory, the innate drive to maintain and enhance the human organism. (p. 429)

acupuncture Traditional Chinese medical procedure involving the insertion and manipulation of fine needles into specific locations on the body to alleviate pain and treat illness; modern acupuncture sometimes involves sending electrical current through the needles rather than manipulating them. (p. 127)

adolescence The transitional stage between late childhood and the beginning of adulthood, during which sexual maturity is reached. (p. 386)

adolescent growth spurt The period of accelerated growth during puberty, involving rapid increases in height and weight. (p. 387)

adrenal cortex The outer portion of the adrenal glands. (p. 59)

adrenal glands The pair of endocrine glands that are involved in the human stress response. (p. 59)

adrenal medulla The inner portion of the adrenal glands, which secretes epinephrine and norepinephrine. (p. 59)

afterimage A visual experience that occurs after the original source of stimulation is no longer present. (p. 96)

aggression Verbal or physical behavior intended to cause harm to other people. (p. 486)

agonist Drug or other chemical substance that binds to a receptor site and triggers a response in the cell. (p. 52)

agoraphobia An anxiety disorder involving extreme fear of experiencing a panic attack or other embarrassing or incapacitating symptoms in a public situation where escape is impossible and help is unavailable. (p. 542)

algorithm A problem-solving strategy that involves following a specific rule, procedure, or method that inevitably produces the correct solution. (p. 279)

alpha brain waves Brain-wave pattern associated with relaxed wakefulness and drowsiness. (p. 141)

altruism Helping another person with no expectation of personal reward or benefit. (p. 483)

Alzheimer’s disease (AD) A progressive disease that destroys the brain’s neurons, gradually impairing memory, thinking, language, and other cognitive functions, resulting in the complete inability to care for oneself; the most common cause of dementia. (p. 262)

amnesia (am-NEE-zha) Severe memory loss. (p. 260)

amphetamines (am-FET-uh-meenz) A class of stimulant drugs that arouse the central nervous system and suppress appetite. (p. 172)

amplitude The intensity or amount of energy of a wave, reflected in the height of the wave; the amplitude of a sound wave determines a sound’s loudness. (p. 98)

amygdala (uh-MIG-dull-uh) An almond-shaped cluster of neurons in the brain’s temporal lobe, involved in memory and emotional responses, especially fear. (pp. 71, 340)

animal cognition or comparative cognition The study of animal learning, memory, thinking, and language. (p. 289)

anorexia nervosa An eating disorder characterized by excessive weight loss, an irrational fear of gaining weight, and distorted body self-perception. (p. 558)

antagonist A drug or other chemical substance that blocks a receptor site and inhibits or prevents a response in the receiving cell. (p. 52)

anterograde amnesia Loss of memory caused by the inability to store new memories; forward-acting amnesia. (p. 260)

anthropomorphism The attribution of human traits, motives, emotions, or behaviors to nonhuman animals or inanimate objects. (p. 345)

antianxiety medications Prescription drugs that are used to alleviate the symptoms of anxiety. (p. 617)

antidepressant medications Prescription drugs that are used to reduce the symptoms associated with major depressive disorder. (p. 618)

antipsychotic medications (an-tee-sy-KAHT-ick or an-ty-sy-KAHT-ick) Prescription drugs that are used to reduce psychotic symptoms; frequently used in the treatment of schizophrenia; also called neuroleptics. (p. 615)

antisocial personality disorder A personality disorder characterized by a pervasive pattern of disregarding and violating the rights of others; such individuals are also often referred to as psychopaths or sociopaths. (p. 563)

anxiety An unpleasant emotional state characterized by physical arousal and feelings of tension, apprehension, and worry. (p. 541)

anxiety disorders A category of psychological disorders in which extreme anxiety is the main diagnostic feature and causes significant disruptions in the person’s cognitive, behavioral, or interpersonal functioning. (p. 541)

aphasia (uh-FAYZH-yuh) The partial or complete inability to articulate ideas or understand spoken or written language because of brain injury or damage. (p. 74)

G-2

aptitude test A test designed to assess a person’s capacity to benefit from education or training. (p. 294)

archetypes (AR-kuh-types) In Jung’s theory, the inherited mental images of universal human instincts, themes, and preoccupations that are the main components of the collective unconscious. (p. 424)

arousal theory The view that people are motivated to maintain a level of arousal that is optimal—neither too high nor too low. (p. 316)

attachment The emotional bond that forms between an infant and caregiver(s), especially his or her parents. (p. 369)

attention The capacity to selectively focus awareness on particular stimuli in your external environment or on your internal thoughts or sensations. (p. 135)

attitude A learned tendency to evaluate some object, person, or issue in a particular way; such evaluations may be positive, negative, or ambivalent. (p. 461)

attribution The mental process of inferring the causes of people’s behavior, including one’s own. Also refers to the explanation made for a particular behavior. (p. 458)

atypical antipsychotic medications Newer antipsychotic medications that, in contrast with the early antipsychotic drugs, block dopamine receptors in brain regions associated with psychotic symptoms rather than more globally throughout the brain, resulting in fewer side effects. (p. 617)

audition The technical term for the sense of hearing. (p. 98)

authoritarian parenting style Parenting style in which parents are demanding and unresponsive toward their children’s needs or wishes. (p. 407)

authoritative parenting style Parenting style in which parents set clear standards for their children’s behavior but are also responsive to their children’s needs and wishes. (p. 407)

autism spectrum disorder Neurodevelopmental disorder characterized by: (1) deficits in social communication and social interaction and (2) restricted, repetitive behaviors, interests, and activities. (p. 300)

autonomic nervous system (aw-toe-NAHM-ick) The subdivision of the peripheral nervous system that regulates involuntary functions. (p. 56)

availability heuristic A strategy in which the likelihood of an event is estimated on the basis of how readily available other instances of the event are in memory. (p. 283)

aversive conditioning A relatively ineffective type of behavior therapy that involves repeatedly pairing an aversive stimulus with the occurrence of undesirable behaviors or thoughts. (p. 597)

axon The long, fluid-filled tube that carries a neuron’s messages to other body areas. (p. 43)

axon terminals The branches at the end of the axon that contain tiny pouches, or sacs, called synaptic vesicles. (p. 48)

B

barbiturates (barb-ITCH-yer-its) A category of depressant drugs that reduce anxiety and produce sleepiness. (p. 168)

basal metabolic rate (BMR) When the body is at rest, the rate at which it uses energy for vital functions, such as heartbeat and respiration. (p. 318)

basic emotions The most fundamental set of emotion categories, which are biologically innate, evolutionarily determined, and culturally universal. (p. 336)

basilar membrane (BAZ-uh-ler or BAYZ-uh-ler) The membrane within the cochlea of the ear that contains the hair cells. (p. 101)

behavior modification The application of learning principles to help people develop more effective or adaptive behaviors. (p. 209)

behavior therapy A type of psychotherapy that focuses on directly changing maladaptive behavior patterns by using basic learning principles and techniques; also called behavior modification. (p. 593)

behavioral genetics An interdisciplinary field that studies the effects of genes and heredity on behavior. (p. 439)

behavioral theories of leader effectiveness Theories of leader effectiveness that focus on differences in the behaviors of effective and ineffective leaders. (p. B-8)

behaviorism School of psychology and theoretical viewpoint that emphasizes the study of observable behaviors, especially as they pertain to the process of learning. (pp. 8, 187)

beta brain waves Brain-wave pattern associated with alert wakefulness. (p. 140)

bilingualism Fluency in two or more languages. (p. 288)

binge-eating disorder An eating disorder characterized by binges of extreme overeating without use of self-induced vomiting or other inappropriate measures to purge the excess food. (p. 558)

binocular cues (by-NOCK-you-ler) Distance or depth cues that require the use of both eyes. (p. 119)

biofeedback Technique that involves using auditory or visual feedback to learn to exert voluntary control over involuntary body functions, such as heart rate, blood pressure, blood flow, and muscle tension. (p. 127)

biological preparedness In learning theory, the idea that an organism is innately predisposed to form associations between certain stimuli and responses. (p. 194)

biological psychology The specialized branch of psychology that studies the relationship between behavior and bodily processes and systems; also called biopsychology or psychobiology. (p. 42)

biomedical therapies The use of medications, electroconvulsive therapy, or other medical treatments to treat the symptoms associated with psychological disorders. (p. 586)

biopsychosocial model The belief that physical health and illness are determined by the complex interaction of biological, psychological, and social factors. (p. 501)

bipolar cells In the retina, the specialized neurons that connect the rods and cones with the ganglion cells. (p. 93)

bipolar disorder A mood disorder involving periods of incapacitating depression alternating with periods of extreme euphoria and excitement; formerly called manic depression. (p. 553)

blaming the victim The tendency to blame an innocent victim of misfortune for having somehow caused the problem or for not having taken steps to avoid or prevent it. (p. 459)

blind spot The point at which the optic nerve leaves the eye, producing a small gap in the field of vision. (p. 93)

body mass index (BMI) A numerical scale indicating adult height in relation to weight; calculated as (703 X weight in pounds)/(height in inches)². (p. 321)

borderline personality disorder A personality disorder characterized by instability of interpersonal relationships, self-image, and emotions, and marked impulsivity. (p. 565)

bottom-up processing Information processing that emphasizes the importance of the sensory receptors in detecting the basic features of a stimulus in the process of recognizing a whole pattern; analysis that moves from the parts to the whole; also called data-driven processing. (p. 110)

brainstem A region of the brain made up of the hindbrain and the midbrain. (p. 65)

brightness The perceived intensity of a color, which corresponds to the amplitude of the light wave. (p. 96)

bulimia nervosa An eating disorder characterized by binges of extreme overeating followed by self-induced vomiting, misuse of laxatives, or other inappropriate methods to purge the excess food and prevent weight gain. (p. 558)

burnout An unhealthy condition caused by chronic, prolonged work stress that is characterized by exhaustion, cynicism, and a sense of failure or inadequacy. (p. 504)

G-3

bystander effect A phenomenon in which the greater the number of people present, the less likely each individual is to help someone in distress. (p. 485)

C

caffeine (kaff-EEN) A stimulant drug found in coffee, tea, cola drinks, chocolate, and many over-the-counter medications. (p. 170)

California Psychological Inventory (CPI) A self-report inventory that assesses personality characteristics in normal populations. (p. 445)

case study An intensive study of a single individual or small group of individuals. (p. 22)

cataplexy A sudden loss of voluntary muscle strength and control that is usually triggered by an intense emotion. (p. 154)

catecholamines (cat-uh-COLE-uh-meenz) Hormones secreted by the adrenal medulla that cause rapid physiological arousal, including adrenaline and noradrenaline. (p. 507)

cell body The part of a cell that processes nutrients and provides energy for the neuron to function; contains the cell’s nucleus; also called the soma. (p. 43)

central nervous system (CNS) The division of the nervous system that consists of the brain and spinal cord. (p. 53)

centration In Piaget’s theory, the tendency to focus, or center, on only one aspect of a situation and ignore other important aspects of the situation. (p. 382)

cerebellum (sair-uh-BELL-um) A large, two-sided hindbrain structure at the back of the brain; responsible for muscle coordination and maintaining posture and equilibrium. (p. 66)

cerebral cortex (suh-REE-brull or SAIR-uh-brull) The wrinkled outer portion of the forebrain, which contains the most sophisticated brain centers. (p. 67)

cerebral hemispheres The nearly symmetrical left and right halves of the cerebral cortex. (p. 67)

chromosome A long, thread-like structure composed of twisted parallel strands of DNA; found in the cell nucleus. (p. 360)

chunking Increasing the amount of information that can be held in short-term memory by grouping related items together into a single unit, or chunk. (p. 232)

circadian rhythm (ser-KADE-ee-en) A cycle or rhythm that is roughly 24 hours long; the cyclical daily fluctuations in biological and psychological processes. (p. 138)

classical conditioning The basic learning process that involves repeatedly pairing a

neutral stimulus with a response-producing stimulus until the neutral stimulus elicits the same response. (p. 183)

client-centered therapy A type of psychotherapy developed by humanistic psychologist Carl Rogers in which the therapist is nondirective and reflective, and the client directs the focus of each therapy session; also called person-centered therapy. (p. 590)

clustering Organizing items into related groups during recall from long-term memory. (p. 236)

cocaine A stimulant drug derived from the leaves of the coca tree. (p. 172)

cochlea (COKE-lee-uh) The coiled, fluid-filled inner-ear structure that contains the basilar membrane and hair cells. (p. 99)

cognition The mental activities involved in acquiring, retaining, and using knowledge. (p. 273)

cognitive appraisal model of stress Developed by Richard Lazarus, a model of stress that emphasizes the role of an individual’s evaluation (appraisal) of events and situations and of the resources that he or she has available to deal with the event or situation. (p. 499)

cognitive appraisal theory of emotion The theory that emotional responses are triggered by a cognitive evaluation. (p. 350)

cognitive dissonance An unpleasant state of psychological tension or arousal (dissonance) that occurs when two thoughts or perceptions (cognitions) are inconsistent; typically results from the awareness that attitudes and behavior are in conflict. (p. 465)

cognitive map Tolman’s term for the mental representation of the layout of a familiar environment. (p. 210)

cognitive therapies A group of psychotherapies based on the assumption that psychological problems are due to illogical patterns of thinking; treatment techniques focus on recognizing and altering these unhealthy thinking patterns. (p. 599)

cognitive therapy (CT) Therapy developed by Aaron T. Beck that focuses on changing the client’s unrealistic and maladaptive beliefs. (p. 601)

cognitive-behavioral therapy (CBT) Therapy that integrates cognitive and behavioral techniques and that is based on the assumption that thoughts, moods, and behaviors are interrelated. (p. 603)

collective unconscious In Jung’s theory, the hypothesized part of the unconscious mind that is inherited from previous generations and that contains universally shared ancestral experiences and ideas. (p. 424)

collectivistic cultures Cultures that emphasize the needs and goals of the group over the needs and goals of the individual. (p. 13)

color The perceptual experience of different wavelengths of light, involving hue, saturation (purity), and brightness (intensity). (p. 95)

color blindness One of several inherited forms of color deficiency or weakness in which an individual cannot distinguish between certain colors. (p. 96)

color constancy The perception of a familiar object as being the same color under different light conditions. (p. 122)

comparative psychology The branch of psychology that studies the behavior of different animal species. (p. 34)

competence motivation The desire to direct your behavior toward demonstrating competence and exercising control in a situation. (p. 334)

comprehension vocabulary The words that are understood by an infant or child. (p. 372)

compulsions Repetitive behaviors or mental acts that a person feels driven to perform in order to prevent or reduce anxiety and distress, or to prevent a dreaded event or situation. (p. 548)

concept A mental category of objects or ideas based on properties they share. (p. 275)

concrete operational stage In Piaget’s theory, the third stage of cognitive development, which lasts from about age 7 to adolescence; characterized by the ability to think logically about concrete objects and situations. (p. 383)

conditional positive regard In Rogers’s theory, the sense that you will be valued and loved only if you behave in a way that is acceptable to others; conditional love or acceptance. (p. 431)

conditioned reinforcer A stimulus or event that has acquired reinforcing value by being associated with a primary reinforcer; also called a secondary reinforcer. (p. 200)

conditioned response (CR) The learned, reflexive response to a conditioned stimulus. (p. 185)

conditioned stimulus (CS) A formerly neutral stimulus that acquires the capacity to elicit a reflexive response. (p. 185)

conditioning The process of learning associations between environmental events and behavioral responses. (p. 183)

cones The short, thick, pointed sensory receptors of the eye that detect color and are responsible for color vision and visual acuity. (p. 93)

confirmation bias The tendency to seek out evidence that confirms an existing belief while ignoring evidence that might contradict or undermine the belief. (p. 21, 284)

G-4

conformity Adjusting your opinions, judgments, or behaviors so that they match the opinions, judgments, or behaviors of other people, or the norms of a social group or situation. (p. 473)

confounding variable A factor or variable other than the ones being studied that, if not controlled, could affect the outcome of an experiment; also called an extraneous variable. (p. 26)

connectome Map of neural connections in the brain (p. 62)

consciousness Personal awareness of mental activities, internal sensations, and the external environment. (p. 135)

conservation In Piaget’s theory, the understanding that two equal quantities remain equal even though the form or appearance is rearranged, as long as nothing is added or subtracted. (p. 382)

context effect The tendency to recover information more easily when the retrieval occurs in the same setting as the original learning of the information. (p. 241)

continuous reinforcement A schedule of reinforcement in which every occurrence of a particular response is followed by a reinforcer. (p. 206)

control group or control condition In an experiment, the group of participants who are exposed to all experimental conditions, except the independent variable; the group against which changes in the experimental group are compared. (p. 26)

coping Behavioral and cognitive responses used to deal with stressors; involves our efforts to change circumstances, or our interpretation of circumstances, to make them more favorable and less threatening. (p. 522)

cornea (CORE-nee-uh) A clear membrane covering the visible part of the eye that helps gather and direct incoming light. (p. 91)

corpus callosum A thick band of axons that connects the two cerebral hemispheres and acts as a communication link between them. (p. 67)

correlation The relationship between two variables. (p. A-8)

correlation coefficient A numerical indication of the magnitude and direction of the relationship (the correlation) between two variables. (pp. 24, A-8)

correlational study A research strategy that allows the precise calculation of how strongly related two factors are to each other. (p. 24)

cortical localization The notion that different functions are located or localized in different areas of the brain; also called localization of function. (pp. 60, 73)

corticosteroids (core-tick-oh-STER-oydz) Hormones released by the adrenal cortex that play a key role in the body’s response to long-term stressors. (p. 509)

counterconditioning A behavior therapy technique based on classical conditioning that involves modifying behavior by conditioning a new response that is incompatible with a previously learned response. (p. 594)

creativity A group of cognitive processes used to generate useful, original, and novel ideas or solutions to problems. (p. 308)

critical thinking The active process of minimizing preconceptions and biases while evaluating evidence, determining the conclusions that can reasonably be drawn from evidence, and considering alternative explanations for research findings or other phenomena. (p. 30)

cross-cultural psychology Branch of psychology that studies the effects of culture on behavior and mental processes. (p. 13)

cross-sectional design Research strategy in which individuals of different ages or developmental stages are directly compared. (p. 358)

cued recall A test of long-term memory that involves remembering an item of information in response to a retrieval cue. (p. 240)

culture The attitudes, values, beliefs, and behaviors shared by a group of people and communicated from one generation to another. (p. 13)

cyclothymic disorder (sie-klo-THY-mick) A mood disorder characterized by moderate but frequent mood swings that are not severe enough to qualify as bipolar disorder. (p. 554)

D

daily hassles Everyday minor events that annoy and upset people. (p. 502)

decay theory The view that forgetting is due to normal metabolic processes that occur in the brain over time. (p. 245)

decibel (DESS-uh-bell) The unit of measurement for loudness. (p. 98)

déjà vu experience A memory illusion characterized by brief but intense feelings of familiarity in a situation that has never been experienced before. (p. 247)

delusion A falsely held belief that persists despite compelling contradictory evidence. (p. 571)

demand characteristics In a research study, subtle cues or signals expressed by the researcher that communicate the kind of response or behavior that is expected from the participant. (p. 28)

dementia Progressive deterioration and impairment of memory, reasoning, and other cognitive functions as the result of disease, injury, or substance abuse. (p. 262)

dendrites The multiple short fibers that extend from a neuron’s cell body and receive information from other neurons or from sensory receptor cells. (p. 43)

deoxyribonucleic acid (DNA) The double-stranded molecule that encodes genetic instructions; the chemical basis of heredity. (p. 360)

dependent variable The factor that is observed and measured for change in an experiment, thought to be influenced by the independent variable; also called the outcome variable. (p. 26)

depressants A category of psychoactive drugs that depress or inhibit brain activity. (p. 165)

depth perception The use of visual cues to perceive the distance or three-dimensional characteristics of objects. (p. 117)

descriptive research Scientific procedures that involve systematically observing behavior in order to describe the relationship among behaviors and events. (p. 21)

descriptive statistics Mathematical methods used to organize and summarize data. (p. A-2)

developmental psychology The branch of psychology that studies how people change over the lifespan. (p. 358)

difference threshold The smallest possible difference between two stimuli that can be detected half the time; also called just noticeable difference. (p. 88)

diffusion of responsibility A phenomenon in which the presence of other people makes it less likely that any individual will help someone in distress because the obligation to intervene is shared among all the onlookers. (p. 485)

discrepancy hypothesis An approach to explaining job satisfaction that focuses on the discrepancy, if any, between what a person wants from a job and how that person evaluates what is actually experienced at work. (p. B-7)

discriminative stimulus A specific stimulus in the presence of which a particular response is more likely to be reinforced, and in the absence of which a particular response is not likely to be reinforced. (p. 203)

displacement The ego defense mechanism that involves unconsciously shifting the target of an emotional urge to a substitute target that is less threatening or dangerous. (p. 420)

G-5

display rules Social and cultural regulations governing emotional expression, especially facial expressions. (p. 345)

dissociation The splitting of consciousness into two or more simultaneous streams of mental activity. (p. 157)

dissociative amnesia A dissociative disorder involving the partial or total inability to recall important personal information. (p. 567)

dissociative anesthetics Class of drugs that reduce sensitivity to pain and produce feelings of detachment and dissociation; includes the club drugs phencyclidine (PCP) and ketamine. (p. 175)

dissociative disorders A category of psychological disorders in which extreme and frequent disruptions of awareness, memory, and personal identity impair the ability to function. (p. 566)

dissociative experience A break or disruption in consciousness during which awareness, memory, and personal identity become separated or divided. (p. 566)

dissociative fugue (fyoog) A type of dissociative amnesia involving sudden and unexpected travel away from home, extensive amnesia, and identity confusion. (p. 567)

dissociative identity disorder (DID) A dissociative disorder involving extensive memory disruptions along with the presence of two or more distinct identities, or “personalities”; formerly called multiple personality disorder. (p. 567)

dopamine (DOPE-uh-meen) Neurotransmitter involved in the regulation of bodily movement, thought processes, and rewarding sensations. (p. 50)

double-blind technique An experimental control in which neither the participants nor the researchers interacting with the participants are aware of the group or condition to which the participants have been assigned. (p. 28)

dream An unfolding sequence of thoughts, perceptions, and emotions that typically occurs during REM sleep and is experienced as a series of real-life events. (p. 147)

dream interpretation A technique used in psychoanalysis in which the content of dreams is analyzed for disguised or symbolic wishes, meanings, and motivations. (p. 589)

drive A need or internal motivational state that activates behavior to reduce the need and restore homeostasis. (p. 316)

drive theories The view that behavior is motivated by the desire to reduce internal tension caused by unmet biological needs. (p. 314)

drug abuse (formally called substance use disorder) Recurrent substance use that involves impaired control, disruption of social, occupational, and interpersonal functioning, and the development of craving, tolerance, and withdrawal symptoms. (p. 165)

drug rebound effect Withdrawal symptoms that are the opposite of a physically addictive drug’s action. (p. 164)

drug tolerance A condition in which increasing amounts of a physically addictive drug are needed to produce the original, desired effect. (p. 164)

DSM-5 Abbreviation for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; the book published by the American Psychiatric Association that describes the specific symptoms and diagnostic guidelines for different psychological disorders. (p. 535)

dyssomnias (dis-SOM-nee-uz) A category of sleep disorders involving disruptions in the amount, quality, or timing of sleep; includes insomnia, obstructive sleep apnea, and narcolepsy. (p. 153)

E

eardrum A tightly stretched membrane at the end of the ear canal that vibrates when hit by sound waves. (p. 99)

eating disorder A category of mental disorders characterized by severe disturbances in eating behavior. (p. 558)

eclecticism (ih-KLEK-tih-siz-um) The pragmatic and integrated use of techniques from different psychotherapies. (p. 612)

EEG (electroencephalogram) The graphic record of brain activity produced by an electroencephalograph. (p. 140)

ego Latin for I; in Freud’s theory, the partly conscious rational component of personality that regulates thoughts and behavior, and is most in touch with the demands of the external world. (p. 418)

ego defense mechanisms Largely unconscious distortions of thoughts or perceptions that act to reduce anxiety. (p. 420)

egocentrism In Piaget’s theory, the inability to take another person’s perspective or point of view. (p. 381)

elaborative rehearsal Rehearsal that involves focusing on the meaning of information to help encode and transfer it to long-term memory. (p. 234)

electroconvulsive therapy (ECT) A biomedical therapy used primarily in the treatment of major depressive disorder that involves electrically inducing a brief brain seizure; also called electroshock therapy. (p. 622)

electroencephalograph (e-lec-tro-en-SEFF-uh-low-graph) An instrument that uses electrodes placed on the scalp to measure and record the brain’s electrical activity. (p. 140)

embryonic period The second period of prenatal development, extending from the third week through the eighth week. (p. 364)

emerging adulthood In industrialized countries, the stage of lifespan from approximately the late teens to the mid-to late-20s, which is characterized by exploration, instability, and flexibility in social roles, vocational choices, and relationships. (p. 396)

emotion A complex psychological state that involves a subjective experience, a physiological response, and a behavioral or expressive response. (p. 336)

emotion-focused coping Coping efforts primarily aimed at relieving or regulating the emotional impact of a stressful situation. (p. 522)

emotional intelligence The capacity to understand and manage your own emotional experiences and to perceive, comprehend, and respond appropriately to the emotional responses of others. (p. 336)

empirical evidence Verifiable evidence that is based upon objective observation, measurement, and/or experimentation. (p. 16)

encoding The process of transforming information into a form that can be entered into and retained by the memory system. (p. 228)

encoding failure The inability to recall specific information because of insufficient encoding of the information for storage in long-term memory. (p. 245)

encoding specificity principle The principle that when the conditions of information retrieval are similar to the conditions of information encoding, retrieval is more likely to be successful. (p. 241)

endocrine system (EN-doe-krin) The system of glands, located throughout the body, that secrete hormones into the bloodstream. (p. 58)

endorphins (en-DORF-inz) Neurotransmitters that regulate pain perceptions. (p. 51)

epigenetics The study of the cellular mechanisms that control gene expression and of the ways that gene expression impacts health and behavior. (p. 362)

episodic memory Category of long-term memory that includes memories of particular events. (p. 235)

ESP (extrasensory perception) Perception of information by some means other than through the normal processes of sensation. (p. 112)

ethnocentrism The belief that one’s own culture or ethnic group is superior to all others and the related tendency to use one’s own culture as a standard by which to judge other cultures. (p. 13)

G-6

evolutionary psychology The application of principles of evolution, including natural selection, to explain psychological processes and phenomena. (p. 13)

exemplars Individual instances of a concept or category, held in memory. (p. 277)

experimental group or experimental condition In an experiment, the group of participants who are exposed to all experimental conditions, including the independent variable. (p. 26)

experimental research A method of investigation used to demonstrate cause-and-effect relationships by purposely manipulating one factor thought to produce change in another factor. (p. 26)

explicit cognition Deliberate, conscious mental processes involved in perceptions, judgments, decisions, and reasoning. (p. 456)

explicit memory Information or knowledge that can be consciously recollected; also called declarative memory. (p. 236)

exposure therapy Behavioral therapy for phobias, panic disorder, posttraumatic stress disorder, or related anxiety disorders in which the person is repeatedly exposed to the disturbing object or situation under controlled conditions. (p. 594)

extinction (in classical conditioning) The gradual weakening and apparent disappearance of conditioned behavior. In classical conditioning, extinction occurs when the conditioned stimulus is repeatedly presented without the unconditioned stimulus. (p. 187)

extinction (in operant conditioning) The gradual weakening and disappearance of conditioned behavior. In operant conditioning, extinction occurs when an emitted behavior is no longer followed by a reinforcer. (p. 206)

extrinsic motivation External factors or influences on behavior, such as rewards, consequences, or social expectations. (p. 333)

F

facial feedback hypothesis The view that expressing a specific emotion, especially facially, causes the subjective experience of that emotion. (p. 349)

false memory A distorted or fabricated recollection of something that did not actually occur. (p. 250)

family therapy A form of psychotherapy that is based on the assumption that the family is a system and that treats the family as a unit. (p. 608)

fetal period The third and longest period of prenatal development, extending from the ninth week until birth. (p. 365)

fight-or-flight response A rapidly occurring chain of internal physical reactions that prepare people to either fight or take flight from an immediate threat. (p. 507)

figure–ground relationship Gestalt principle stating that a perception is automatically separated into the figure, which clearly stands out, from its less distinct background, the ground. (p. 113)

five-factor model of personality A trait theory of personality that identifies extraversion, neuroticism, agreeableness, conscientiousness, and openness to experience as the fundamental building blocks of personality. (p. 439)

fixed-interval (FI) schedule A reinforcement schedule in which a reinforcer is delivered for the first response that occurs after a preset time interval has elapsed. (p. 208)

fixed-ratio (FR) schedule A reinforcement schedule in which a reinforcer is delivered after a fixed number of responses has occurred. (p. 207)

flashbulb memory The recall of very specific images or details surrounding a vivid, rare, or significant personal event; details may or may not be accurate. (p. 241)

forebrain The largest and most complex brain region, which contains centers for complex behaviors and mental processes; also called the cerebrum. (p. 66)

forgetting The inability to recall information that was previously available. (p. 243)

formal concept A mental category that is formed by learning the rules or features that define it. (p. 275)

formal operational stage In Piaget’s theory, the fourth stage of cognitive development, which lasts from adolescence through adulthood; characterized by the ability to think logically about abstract principles and hypothetical situations. (p. 383)

fovea (FOE-vee-uh) A small area in the center of the retina, composed entirely of cones, where visual information is most sharply focused. (p. 93)

free association A psychoanalytic technique in which the patient spontaneously reports all thoughts, feelings, and mental images that arise, revealing unconscious thoughts and emotions. (pp. 417, 588)

frequency The rate of vibration, or the number of sound waves per second. (p. 98)

frequency distribution A summary of how often various scores occur in a sample of scores. Score values are arranged in order of magnitude, and the number of times each score occurs is recorded. (p. A-2)

frequency polygon A way of graphically representing a frequency distribution; frequency is marked above each score category on the graph’s horizontal axis, and the marks are connected by straight lines. (p. A-3)

frequency theory The view that the basilar membrane vibrates at the same frequency as the sound wave. (p. 101)

frontal lobe The largest lobe of each cerebral hemisphere; processes voluntary muscle movements and is involved in thinking, planning, and emotional control. (p. 69)

functional fixedness The tendency to view objects as functioning only in their usual or customary way. (p. 281)

functional magnetic resonance imaging (fMRI) A noninvasive imaging technique that uses magnetic fields to map brain activity by measuring changes in the brain’s blood flow and oxygen levels. (p. 33)

functional plasticity The brain’s ability to shift functions from damaged to undamaged brain areas. (p. 62)

functionalism Early school of psychology that emphasized studying the purpose, or function, of behavior and mental experiences. (p. 6)

fundamental attribution error The tendency to attribute the behavior of others to internal, personal characteristics, while ignoring or underestimating the effects of external, situational factors; an attributional bias that is common in individualistic cultures. (p. 458)

G

g factor or general intelligence The notion of a general intelligence factor that is responsible for a person’s overall performance on tests of mental ability. (p. 295)

GABA (gamma-aminobutyric acid) Neurotransmitter that usually communicates an inhibitory message. (p. 51)

ganglion cells In the retina, the specialized neurons that connect to the bipolar cells; the bundled axons of the ganglion cells form the optic nerve. (p. 93)

gate-control theory of pain The theory that pain is a product of both physiological and psychological factors that cause spinal gates to open and relay patterns of intense stimulation to the brain, which perceives them as pain. (p. 108)

gender The cultural, social, and psychological meanings that are associated with masculinity or femininity. (p. 375)

gender identity A person’s psychological sense of being male or female. (p. 375)

gender roles The behaviors, attitudes, and personality traits that are designated as either masculine or feminine in a given culture. (p. 375)

G-7

gender schema theory The theory that gender-role development is influenced by the formation of schemas, or mental representations, of masculinity and femininity. (p. 376)

gene A unit of DNA on a chromosome that encodes instructions for making a particular protein molecule; the basic unit of heredity. (p. 361)

general adaptation syndrome Hans Selye’s term for the three-stage progression of physical changes that occur when an organism is exposed to intense and prolonged stress. The three stages are alarm, resistance, and exhaustion. (p. 509)

generalized anxiety disorder (GAD) An anxiety disorder characterized by excessive, global, and persistent symptoms of anxiety; also called free-floating anxiety. (p. 541)

genotype (JEEN-oh-type) The genetic makeup of an individual organism. (p. 361)

germinal period The first two weeks of prenatal development. (p. 363)

Gestalt psychology (geh-SHTALT) School of psychology that maintained sensations are actively processed according to consistent perceptual rules, producing meaningful whole perceptions, or gestalts. (p. 110)

glial cells or glia (GLEE-ull) The support cells that assist neurons by providing structural support, nutrition, and removal of cell wastes; glial cells manufacture myelin. (p. 44)

glucose Simple sugar that provides energy and is primarily produced by the conversion of carbohydrates and fats; commonly called blood sugar. (p. 318)

glutamate Neurotransmitter that usually communicates an excitatory message. (p. 51)

gonads The endocrine glands that secrete hormones that regulate sexual characteristics and reproductive processes; ovaries in females and testes in males. (p. 60)

graphology A pseudoscience that claims to assess personality, social, and occupational attributes based on a person’s distinctive handwriting, doodles, and drawing style. (p. 442)

group therapy A form of psychotherapy that involves one or more therapists working simultaneously with a small group of clients. (p. 605)

gustation Technical name for the sense of taste. (p. 103)

H

hair cells The hair-like sensory receptors for sound, which are embedded in the basilar membrane of the cochlea. (p. 101)

hallucination A false or distorted perception that seems vividly real to the person experiencing it. (p. 571)

health psychology The branch of psychology that studies how biological, behavioral, and social factors influence health, illness, medical treatment, and health-related behaviors. (p. 500)

heritability The percentage of variation within a given population that is due to heredity. (p. 302)

heuristic A problem-solving strategy that involves following a general rule of thumb to reduce the number of possible solutions. (p. 279)

hidden observer Hilgard’s term for the hidden, or dissociated, stream of mental activity that continues during hypnosis. (p. 158)

hierarchy of needs Maslow’s hierarchical division of motivation into levels that progress from basic physical needs to psychological needs to self-fulfillment needs. (p. 331)

higher order conditioning (also called second-order conditioning) A procedure in which a conditioned stimulus from one learning trial functions as the unconditioned stimulus in a new conditioning trial; the second conditioned stimulus comes to elicit the conditioned response, even though it has never been directly paired with the unconditioned stimulus. (p. 186)

hindbrain A region at the base of the brain that contains several structures that regulate basic life functions. (p. 65)

hindsight bias The tendency to overestimate one’s ability to have foreseen or predicted the outcome of an event. (p. 459)

hippocampus A curved forebrain structure that is part of the limbic system and is involved in learning and forming new memories. (p. 71)

histogram A way of graphically representing a frequency distribution; a type of bar chart that uses vertical bars that touch. (p. A-3)

homeostasis (home-ee-oh-STAY-sis) The idea that the body monitors and maintains internal states, such as body temperature and energy supplies, at relatively constant levels; in general, the tendency to reach or maintain equilibrium. (p. 314)

hormones Chemical messengers secreted into the bloodstream primarily by endocrine glands. (p. 58)

hue The property of wavelengths of light known as color; different wavelengths correspond to our subjective experience of different colors. (p. 95)

humanistic psychology School of psychology and theoretical viewpoint that emphasizes each person’s unique potential for psychological growth and self-direction. (p. 9)

humanistic psychology (theory of personality) The theoretical viewpoint on personality that generally emphasizes the inherent goodness of people, human potential, self-actualization, the self-concept, and healthy personality development. (p. 429)

humanistic theories of motivation The view that emphasizes the importance of psychological and cognitive factors in motivation, especially the notion that people are motivated to realize their personal potential. (p. 317)

hypnagogic hallucinations (hip-na-GAH-jick) Vivid sensory phenomena that occur during the onset of sleep. ( p. 141)

hypnosis (hip-NO-sis) A cooperative social interaction in which the hypnotized person responds to the hypnotist’s suggestions with changes in perception, memory, and behavior. (p. 156)

hypothalamus (hi-poe-THAL-uh-muss) A peanut-sized forebrain structure that is part of the limbic system and that regulates behaviors related to survival, such as eating, drinking, and sexual activity. (p. 71)

hypothesis (high-POTH-uh-sis) A tentative statement about the relationship between two or more variables; a testable prediction or question. (p. 16)

I

id Latin for the it; in Freud’s theory, the completely unconscious, irrational component of personality that seeks immediate satisfaction of instinctual urges and drives; ruled by the pleasure principle. (p. 418)

identification In psychoanalytic theory, an ego defense mechanism that involves reducing anxiety by imitating the behavior and characteristics of another person. (p. 422)

identity A person’s sense of self, including his or her memories, experiences, and the values and beliefs that guide his or her behavior. (p. 391)

imagination inflation A memory phenomenon in which vividly imagining an event markedly increases confidence that the event actually occurred. (p. 253)

immune system Body system that produces specialized white blood cells that protect the body from viruses, bacteria, and tumor cells. (p. 511)

implicit attitudes Preferences and biases toward particular groups that are automatic, spontaneous, unintentional, and often unconscious; measured with the Implicit Associations Test (IAT). (p. 469)

implicit cognition Automatic, nonconscious mental processes that influence perceptions, judgments, decisions, and reasoning. (p. 456)

implicit memory Information or knowledge that affects behavior or task performance but cannot be consciously recollected; also called non-declarative memory. (p. 236)

G-8

implicit personality theory A network of assumptions or beliefs about the relationships among various types of people, traits, and behaviors. (p. 456)

in-group A social group to which one belongs. (p. 467)

in-group bias The tendency to judge the behavior of in-group members favorably and out-group members unfavorably. (p. 469)

incentive theories The view that behavior is motivated by the pull of external goals, such as rewards. (p. 316)

independent variable The purposely manipulated factor thought to produce change in an experiment; also called the treatment variable. (p. 26)

individualistic cultures Cultures that emphasize the needs and goals of the individual over the needs and goals of the group. (p. 13)

induction A discipline technique that combines parental control with explaining why a behavior is prohibited. (p. 408)

industrial/organizational (I/O) psychology The branch of psychology that focuses on the study of human behavior in the workplace. (p. B-1)

inferential statistics Mathematical methods used to determine how likely it is that a study’s outcome is due to chance and whether the outcome can be legitimately generalized to a larger population. (p. A-11)

information-processing model of cognitive development The model that views cognitive development as a process that is continuous over the lifespan and that studies the development of basic mental processes such as attention, memory, and problem solving. (p. 386)

informational social influence Behavior that is motivated by the desire to be correct. (p. 473)

inhalants Chemical substances that are inhaled to produce an alteration in consciousness. (p. 168)

inner ear The part of the ear where sound is transduced into neural impulses; consists of the cochlea and semicircular canals. (p. 99)

insight The sudden realization of how a problem can be solved. (p. 279)

insomnia A condition in which a person regularly experiences an inability to fall asleep, to stay asleep, or to feel adequately rested by sleep. (p. 153)

instinct theories The view that certain human behaviors are innate and due to evolutionary programming. (p. 314)

instinctive drift The tendency of an animal to revert to instinctive behaviors that can interfere with the performance of an operantly conditioned response. (p. 214)

insulin Hormone produced by the pancreas that regulates blood levels of glucose and signals the hypothalamus, regulating hunger and eating behavior. (p. 318)

intellectual disability Formerly called mental retardation. Neurodevelopmental disorder characterized by deficits in general mental abilities which result in impairments of adaptive functioning, such that the individual fails to meet standards of personal independence and social responsibility. (p. 300)

intelligence The global capacity to think rationally, act purposefully, and deal effectively with the environment. (p. 290)

intelligence quotient (IQ) A measure of general intelligence derived by comparing an individual’s score with the scores of others in the same age group. (p. 291)

interference theory The theory that forgetting is caused by one memory competing with or replacing another. (p. 247)

interneuron The type of neuron that communicates information from one neuron to the next. (p. 43)

interpersonal engagement Emotion dimension reflecting the degree to which emotions involve a relationship with another person or other people. (p. 337)

interpersonal therapy (IPT) A brief psychodynamic psychotherapy that focuses on current relationships and is based on the assumption that symptoms are caused and maintained by interpersonal problems. (p. 590)

interpretation A technique used in psychoanalysis in which the psychoanalyst offers a carefully timed explanation of the patient’s dreams, free associations, or behaviors to facilitate the recognition of unconscious conflicts or motivations. (p. 589)

intrinsic motivation The desire to engage in tasks that are inherently satisfying and enjoyable, novel, or optimally challenging; the desire to do something for its own sake. (p. 333)

intuition Coming to a conclusion or making a judgment without conscious awareness of the thought processes involved. (p. 279)

iris (EYE-riss) The colored part of the eye, which is the muscle that controls the size of the pupil. (p. 91)

irreversibility In Piaget’s theory, the inability to mentally reverse a sequence of events or logical operations. (p. 381)

J

James–Lange theory of emotion The theory that emotions arise from the perception of body changes. (p. 347)

job analysis A technique that identifies the major responsibilities of a job, along with the human characteristics needed to fill it. (p. B-3)

just-world hypothesis The assumption that the world is fair and that therefore people get what they deserve and deserve what they get. (p. 459)

K

K complex Single but large high-voltage spike of brain activity that characterizes stage 2 NREM sleep. (p. 142)

kinesthetic sense (kin-ess-THET-ick) The technical name for the sense of location and position of body parts in relation to one another. (p. 109)

L

language A system for combining arbitrary symbols to produce an infinite number of meaningful statements. (p. 284)

latent content In Freud’s psychoanalytic theory, the unconscious wishes, thoughts, and urges that are concealed in the manifest content of a dream. (p. 149)

latent learning Tolman’s term for learning that occurs in the absence of reinforcement but is not behaviorally demonstrated until a reinforcer becomes available. (p. 211)

lateralization of function The notion that specific psychological or cognitive functions are processed primarily on one side of the brain. (p. 73)

law of effect Learning principle, proposed by Thorndike, in which responses followed by a satisfying effect become strengthened and are more likely to recur in a particular situation, while responses followed by a dissatisfying effect are weakened and less likely to recur in a particular situation. (p. 197)

leader–member exchange model A model of leadership emphasizing that the quality of the interactions between supervisors and subordinates varies depending on the unique characteristics of both. (p. B-9)

learned helplessness A phenomenon in which exposure to inescapable and uncontrollable aversive events produces passive behavior. (p. 212)

learning A process that produces a relatively enduring change in behavior or knowledge as a result of past experience. (p. 183)

lens A transparent structure, located behind the pupil, that actively focuses, or bends, light as it enters the eye. (p. 91)

leptin Hormone produced by fat cells that signals the hypothalamus, regulating hunger and eating behavior. (p. 319)

G-9

libido The psychological and emotional energy associated with expressions of sexuality; the sex drive. (p. 418)

limbic system A group of forebrain structures that form a border around the brainstem and are involved in emotion, motivation, learning, and memory. (p. 71)

linguistic relativity hypothesis The hypothesis that differences among languages cause differences in the thoughts of their speakers. (p. 286)

lithium A naturally occurring substance that is used in the treatment of bipolar disorder. (p. 618)

long-term memory The stage of memory that represents the long-term storage of information. (p. 229)

long-term potentiation A long-lasting increase in synaptic strength between two neurons. (p. 258)

longitudinal design Research strategy in which a variable or group of variables are studied in the same group of participants over time. (p. 358)

loudness The intensity (or amplitude) of a sound wave, measured in decibels. (p. 98)

LSD A synthetic psychedelic drug. (p. 172)

lymphocytes (LIMF-oh-sites) Specialized white blood cells that are responsible for immune defenses. (p. 511)

M

magnetic resonance imaging (MRI) A noninvasive imaging technique that produces highly detailed images of the body’s structures and tissues, using electromagnetic signals generated by the body in response to magnetic fields. (p. 32)

maintenance rehearsal The mental or verbal repetition of information in order to maintain it beyond the usual 20-second duration of short-term memory. (p. 231)

major depressive disorder A mood disorder characterized by extreme and persistent feelings of despondency, worthlessness, and hopelessness, causing impaired emotional, cognitive, behavioral, and physical functioning. (p. 550)

manic episode A sudden, rapidly escalating emotional state characterized by extreme euphoria, excitement, physical energy, and rapid thoughts and speech. (p. 553)

manifest content In Freud’s psychoanalytic theory, the elements of a dream that are consciously experienced and remembered by the dreamer. (p. 149)

marijuana A psychoactive drug derived from the hemp plant. (p. 174)

MDMA or ecstasy Synthetic club drug that combines stimulant and mild psychedelic effects. (p. 174)

mean The sum of a set of scores in a distribution divided by the number of scores; the mean is usually the most representative measure of central tendency. (p. A-5)

measure of central tendency A single number that presents some information about the “center” of a frequency distribution. (p. A-4)

measure of variability A single number that presents information about the spread of scores in a distribution. (p. A-5)

median The score that divides a frequency distribution exactly in half so that the same number of scores lie on each side of it. (p. A-5)

meditation Any one of a number of sustained concentration techniques that focus attention and heighten awareness. (p. 160)

medulla (muh-DOOL-uh) A hindbrain structure that controls vital life functions such as breathing and circulation. (p. 65)

melatonin (mel-uh-TONE-in) A hormone manufactured by the pineal gland that produces sleepiness. (p. 138)

memory The mental processes that enable you to retain and retrieve information over time. (p. 228)

memory consolidation The gradual, physical process of converting new long-term memories to stable, enduring memory codes. (p. 260)

memory trace or engram The hypothetical brain changes associated with a particular stored memory. (p. 256)

menarche (meh-NAR-kee) A female’s first menstrual period, which occurs during puberty. (p. 387)

menopause The natural cessation of menstruation and the end of reproductive capacity in women. (p. 398)

mental age A measurement of intelligence in which an individual’s mental level is expressed in terms of the average abilities of a given age group. (p. 291)

mental image A mental representation of objects or events that are not physically present. (p. 273)

mental set The tendency to persist in solving problems with solutions that have worked in the past. (p. 281)

mere exposure effect The finding that repeated exposure to a stimulus increases a person’s preference for that stimulus. (p. 89)

mescaline (MESS-kuh-lin) A psychedelic drug derived from the peyote cactus. (p. 172)

meta-analysis A statistical technique that involves combining and analyzing the results of many research studies on a specific topic in order to identify overall trends. (p. 18)

midbrain The middle and smallest brain region, involved in processing auditory and visual sensory information. (p. 66)

middle ear The part of the ear that amplifies sound waves; consists of three small bones: the hammer, the anvil, and the stirrup. (p. 99)

mindfulness meditation A technique in which practitioners focus awareness on present experience with acceptance. (p. 528)

Minnesota Multiphasic Personality Inventory (MMPI) A self-report inventory that assesses personality characteristics and psychological disorders; used to assess both normal and disturbed populations. (p. 444)

mirror neurons Neurons that activate both when an action is performed and when the same action is perceived. (p. 217)

misinformation effect A memory-distortion phenomenon in which your existing memories can be altered if you are exposed to misleading information. (p. 249)

mode The most frequently occurring score in a distribution. (p. A-4)

monocular cues (moe-NOCK-you-ler) Distance or depth cues that can be processed by either eye alone. (p. 117)

mood congruence An encoding specificity phenomenon in which a given mood tends to evoke memories that are consistent with that mood. (p. 241)

moon illusion A visual illusion involving the misperception that the moon is larger when it is on the horizon than when it is directly overhead. (p. 124)

moral reasoning The aspect of cognitive development that has to do with how an individual reasons about moral decisions. (p. 393)

motivation The biological, emotional, cognitive, or social forces that activate and direct behavior. (p. 314)

motor neuron The type of neuron that signals muscles to relax or contract. (p. 43)

Müller-Lyer illusion A famous visual illusion involving the misperception of the identical length of two lines, one with arrows pointed inward, one with arrows pointed outward. (p. 123)

myelin sheath (MY-eh-lin) A white, fatty covering wrapped around the axons of some neurons that increases their communication speed. (p. 44)

N

narcolepsy (NAR-ko-lep-see) A sleep disorder characterized by excessive daytime sleepiness and brief lapses into sleep throughout the day. (p. 153)

natural concept A mental category that is formed as a result of everyday experience. (p. 277)

G-10

natural experiment A study investigating the effects of a naturally occurring event on the research participants. (p. 29)

naturalistic observation The systematic observation and recording of behaviors as they occur in their natural setting. (p. 22)

negative correlation A finding that two factors vary systematically in opposite directions, one increasing as the other decreases. (pp. 25, A-8)

negative punishment A situation in which an operant is followed by the removal or subtraction of a reinforcing stimulus; also called punishment by removal. (p. 201)

negative reinforcement A situation in which a response results in the removal of, avoidance of, or escape from a punishing stimulus, increasing the likelihood that the response will be repeated in similar situations. (p. 199)

negative symptoms In schizophrenia, symptoms that reflect defects or deficits in normal functioning, including flat affect, alogia, and avolition. (p. 571)

neodissociation theory of hypnosis Theory proposed by Ernest Hilgard that explains hypnotic effects as being due to the splitting of consciousness into two simultaneous streams of mental activity, only one of which the hypnotic participant is consciously aware during hypnosis. (p. 158)

nerves Bundles of neuron axons that carry information in the peripheral nervous system. (p. 53)

nervous system The primary internal communication network of the body; divided into the central nervous system and the peripheral nervous system. (p. 53)

neurocognitive model of dreaming Model of dreaming that emphasizes the continuity of waking and dreaming cognition, and states that dreaming is like thinking under conditions of reduced sensory input and the absence of voluntary control. (p. 151)

neurogenesis The development of new neurons. (p. 63)

neuron A highly specialized cell that communicates information in electrical and chemical form; a nerve cell. (p. 43)

neuropeptide Y (NPY) Neurotransmitter found in several brain areas, most notably the hypothalamus, that stimulates eating behavior and reduces metabolism, promoting positive energy balance and weight gain. (p. 320)

neuroscience The study of the nervous system, especially the brain. (pp. 10, 42)

neurotransmitters Chemical messengers manufactured by a neuron. (p. 48)

nicotine A stimulant drug found in tobacco products. (p. 171)

nightmare A vivid and frightening or unpleasant anxiety dream that occurs during REM sleep. (p. 149)

nociceptors Specialized sensory receptors for pain that are found in the skin, muscles, and internal organs. (p. 107)

norepinephrine (nor-ep-in-EF-rin) Neurotransmitter involved in learning, memory, and regulation of sleep; also, a hormone manufactured by adrenal glands. (p. 51)

normal curve or normal distribution A bell-shaped distribution of individual differences in a normal population in which most scores cluster around the average score. (p. 295)

normative social influence Behavior that is motivated by the desire to gain social acceptance and approval. (p. 473)

NREM sleep Quiet, typically dreamless sleep in which rapid eye movements are absent; divided into four stages; also called quiet sleep. (p. 140)

O

obedience The performance of a behavior in response to a direct command. (p. 475)

obese Condition characterized by excessive body fat and a body mass index equal to or greater than 30.0. (p. 321)

object permanence The understanding that an object continues to exist even when it can no longer be seen. (p. 381)

observational learning Learning that occurs through observing the actions of others. (p. 214)

obsessions Repeated, intrusive, and uncontrollable irrational thoughts or mental images that cause extreme anxiety and distress. (p. 548)

obsessive–compulsive disorder (OCD) Disorder characterized by the presence of intrusive, repetitive, and unwanted thoughts (obsessions) and repetitive behaviors or mental acts that an individual feels driven to perform (compulsions). (p. 548)

obstructive sleep apnea (APP-nee-uh) A sleep disorder in which the person repeatedly stops breathing during sleep. (p. 153)

occipital lobe (ock-SIP-it-ull) An area at the back of each cerebral hemisphere that is the primary receiving area for visual information. (p. 69)

Oedipus complex In Freud’s theory, a child’s unconscious sexual desire for the opposite-sex parent, usually accompanied by hostile feelings toward the same-sex parent. (p. 422)

olfaction Technical name for the sense of smell. (p. 103)

olfactory bulb (ole-FACK-tuh-ree) The enlarged ending of the olfactory cortex at the front of the brain where the sensation of smell is registered. (p. 104)

operant Skinner’s term for an actively emitted (or voluntary) behavior that operates on the environment to produce consequences. (p. 198)

operant chamber or Skinner box The experimental apparatus invented by B.F. Skinner to study the relationship between environmental events and active behaviors. (p. 205)

operant conditioning The basic learning process that involves changing the probability that a response will be repeated by manipulating the consequences of that response. (p. 198)

operational definition A precise description of how the variables in a study will be manipulated or measured. (p. 16)

opioids (OH-pee-oidz) A category of psychoactive drugs that are chemically similar to morphine and have strong pain-relieving properties; also called opiates or narcotics. (p. 169)

opponent-process theory of color vision The theory that color vision is the product of opposing pairs of color receptors: red—green, blue—yellow, and black—white; when one member of a color pair is stimulated, the other member is inhibited. (p. 97)

optic chiasm (KY-az-uhm) The point in the brain where the optic nerve fibers from each eye meet and partly cross over to the opposite side of the brain. (p. 94)

optic disk Area of the retina without rods or cones, where the optic nerve exits the back of the eye. (p. 93)

optic nerve The thick nerve that exits from the back of the eye and carries visual information to the visual cortex in the brain. (p. 93)

optimistic explanatory style Accounting for negative events or situations with external, unstable, and specific explanations. (p. 515)

organizational behavior A subarea of I/O psychology that focuses on the workplace culture and its influence on employee behavior. (p. B-2)

out-group A social group to which one does not belong. (p. 467)

out-group homogeneity effect The tendency to see members of out-groups as very similar to one another. (p. 469)

outer ear The part of the ear that collects sound waves; consists of the pinna, the ear canal, and the eardrum. (p. 99)

oxytocin Hormone involved in reproduction, social motivation, and social behavior. (p. 59)

G-11

P

pain The unpleasant sensation of physical discomfort or suffering that can occur in varying degrees of intensity. (p. 106)

panic attack A sudden episode of extreme anxiety that rapidly escalates in intensity. (p. 542)

panic disorder An anxiety disorder in which the person experiences frequent and unexpected panic attacks. (p. 542)

parapsychology The scientific investigation of claims of paranormal phenomena and abilities. (p. 112)

parasomnias (pare-uh-SOM-nee-uz) A category of sleep disorders characterized by arousal or activation during sleep or sleep transitions; includes sleepwalking, sleep terrors, sleepsex, and sleep-related eating disorder. (p. 153)

parasympathetic nervous system The branch of the autonomic nervous system that maintains normal bodily functions and conserves the body’s physical resources. (p. 57)

parietal lobe (puh-RYE-ut-ull) An area on each hemisphere of the cerebral cortex located above the temporal lobe that processes somatic sensations. (p. 69)

partial reinforcement A situation in which the occurrence of a particular response is only sometimes followed by a reinforcer. (p. 206)

partial reinforcement effect The phenomenon in which behaviors that are conditioned using partial reinforcement are more resistant to extinction than behaviors that are conditioned using continuous reinforcement. (p. 206)

perception The process of integrating, organizing, and interpreting sensations. (p. 86)

perceptual constancy The tendency to perceive objects, especially familiar objects, as constant and unchanging despite changes in sensory input. (p. 121)

perceptual illusion The misperception of the true characteristics of an object or an image. (p. 123)

perceptual set The tendency to perceive objects or situations from a particular frame of reference. (p. 125)

peripheral nervous system (per-IF-er-ull) The division of the nervous system that includes all the nerves lying outside the central nervous system. (p. 55)

permissive parenting style Parenting style in which parents are extremely tolerant and not demanding; permissive-indulgent parents are responsive to their children, while permissive-indifferent parents are unresponsive. (p. 407)

persistent depressive disorder A disorder involving chronic feelings of depression that is often less severe than major depressive disorder. (p. 552)

person perception The mental processes we use to form judgments and draw conclusions about the characteristics and motives of other people. (p. 454)

personality An individual’s unique and relatively consistent patterns of thinking, feeling, and behaving. (p. 415)

personality disorder Inflexible, maladaptive patterns of thoughts, emotions, behavior, and interpersonal functioning that are stable over time and across situations and that deviate from the expectations of the individual’s culture. (p. 562)

personality theory A theory that attempts to describe and explain similarities and differences in people’s patterns of thinking, feeling, and behaving. (p. 415)

personnel psychology A subarea of I/O psychology that focuses on matching people’s characteristics to job requirements, accurately measuring job performance, and assessing employee training needs. (p. B-2)

persuasion The deliberate attempt to influence the attitudes or behavior of another person in a situation in which that person has some freedom of choice. (p. 491)

pessimistic explanatory style Accounting for negative events or situations with internal, stable, and global explanations. (p. 515)

phenotype (FEEN-oh-type) The observable traits or characteristics of an organism as determined by the interaction of genetics and environmental factors. (p. 361)

pheromones Chemical signals released by an animal that communicate information and affect the behavior of other animals of the same species. (p. 103)

phobia A persistent and irrational fear of a specific object, situation, or activity. (p. 543)

phrenology (freh-NAHL-uh-jee) A pseudoscientific theory of the brain that claimed that personality characteristics, moral character, and intelligence could be determined by examining the bumps on a person’s skull. (p. 60)

physical dependence A condition in which a person has physically adapted to a drug so that he or she must take the drug regularly in order to avoid withdrawal symptoms. (p. 164)

pitch The relative highness or lowness of a sound, determined by the frequency of a sound wave. (p. 98)

pituitary gland (pih-TOO-ih-tare-ee) The endocrine gland attached to the base of the brain that secretes hormones affecting the function of other glands as well as hormones that act directly on physical processes. (p. 59)

place theory The view that different frequencies cause larger vibrations at different locations along the basilar membrane. (p. 103)

placebo A fake substance, treatment, or procedure that has no known direct effects. (p. 29)

placebo effect Any change attributed to a person’s beliefs and expectations rather than to an actual drug, treatment, or procedure. (p. 29)

placebo response An individual’s psychological and physiological response to what is actually a fake treatment or drug; also called placebo effect. (p. 192)

pleasure principle The motive to obtain pleasure and avoid tension or discomfort; the most fundamental human motive and the guiding principle of the id. (p. 418)

pons A hindbrain structure that connects the medulla to the two sides of the cerebellum; helps coordinate and integrate movements on each side of the body. (p. 66)

population A complete set of something— people, nonhuman animals, objects, or events. (p. A-12)

positive correlation A finding that two factors vary systematically in the same direction, increasing or decreasing together. (pp. 25, A-8)

positive psychology The study of positive emotions and psychological states, positive individual traits, and the social institutions that foster positive individuals and communities. (p. 11)

positive punishment A situation in which an operant is followed by the presentation or addition of an aversive stimulus; also called punishment by application. (p. 200)

positive reinforcement A situation in which a response is followed by the addition of a reinforcing stimulus, increasing the likelihood that the response will be repeated in similar situations. (p. 198)

positive symptoms In schizophrenia, symptoms that reflect excesses or distortions of normal functioning, including delusions, hallucinations, and disorganized thoughts and behavior. (p. 571)

positron emission tomography (PET) scan An invasive imaging technique that provides color-coded images of brain activity by tracking the brain’s use of a radioactively tagged compound, such as glucose, oxygen, or a drug. ( p. 32 )

possible selves The aspect of the self-concept that includes images of the selves that you hope, fear, or expect to become in the future. (p. 447)

G-12

posthypnotic amnesia The inability to recall specific information because of a hypnotic suggestion. (p. 156)

posthypnotic suggestion A suggestion made during hypnosis asking a person to carry out a specific instruction following the hypnotic session. (p. 156)

posttraumatic stress disorder (PTSD) A disorder triggered by exposure to a highly traumatic event that results in recurrent, involuntary, and intrusive memories of the event; avoidance of stimuli and situations associated with the event; negative changes in thoughts, moods, and emotions; and a persistent state of heightened physical arousal. (p. 546)

prejudice A negative attitude toward people who belong to a specific social group. (p. 465)

prenatal stage The stage of development before birth; divided into the germinal, embryonic, and fetal periods. (p. 363)

preoperational stage In Piaget’s theory, the second stage of cognitive development, which lasts from about age 2 to age 7; characterized by increasing use of symbols and prelogical thought processes. (p. 381)

primary reinforcer A stimulus or event that is naturally or inherently reinforcing for a given species, such as food, water, or other biological necessities. (p. 200)

primary sex characteristics Sexual organs that are directly involved in reproduction, such as the uterus, ovaries, penis, and testicles. (p. 386)

proactive interference Forgetting in which an old memory interferes with remembering a new memory; forward-acting memory interference. (p. 247)

problem solving Thinking and behavior directed toward attaining a goal that is not readily available. (p. 277)

problem-focused coping Coping efforts primarily aimed at directly changing or managing a threatening or harmful stressor. (p. 522)

procedural memory Category of long-term memory that includes memories of different skills, operations, and actions. (p. 235)

production vocabulary The words that an infant or child understands and can speak. (p. 372)

projective test A type of personality test that involves a person’s interpreting an ambiguous image; used to assess unconscious motives, conflicts, psychological defenses, and personality traits. (p. 442)

proprioceptors (pro-pree-oh-SEP-terz) Sensory receptors, located in the muscles and joints, that provide information about body position and movement. (p. 109)

prosocial behavior Any behavior that helps another, whether the underlying motive is self-serving or selfless. (p. 483)

prospective memory Remembering to do something in the future. (p. 245)

prototype The most typical instance of a particular concept. (p. 277)

pseudoscience Fake or false science that makes claims based on little or no scientific evidence. (p. 20)

psychedelic drugs (sy-kuh-DEL-ick) A category of psychoactive drugs that create sensory and perceptual distortions, alter mood, and affect thinking. (p. 172)

psychiatry Medical specialty area focused on the diagnosis, treatment, causes, and prevention of mental and behavioral disorders. (p. 15)

psychoactive drug A drug that alters consciousness, perception, mood, and behavior. (p. 164)

psychoanalysis Personality theory and form of psychotherapy that emphasizes the role of unconscious factors in personality and behavior. (p. 7)

psychoanalysis (in personality) Sigmund Freud’s theory of personality, which emphasizes unconscious determinants of behavior, sexual and aggressive instinctual drives, and the enduring effects of early childhood experiences on later personality development. (p. 415)

psychoanalysis (in psychotherapy) A type of psychotherapy originated by Sigmund Freud in which free association, dream interpretation, and analysis of resistance and transference are used to explore repressed or unconscious impulses, anxieties, and internal conflicts. (p. 588)

psychological disorder or mental disorder A pattern of behavioral and psychological symptoms that causes significant personal distress, impairs the ability to function in one or more important areas of life, or both. (p. 535)

psychological test A test that assesses a person’s abilities, aptitudes, interests, or personality on the basis of a systematically obtained sample of behavior. (p. 442)

psychology The scientific study of behavior and mental processes. (p. 2)

psychoneuroimmunology An interdisciplinary field that studies the interconnections among psychological processes, nervous and endocrine system functions, and the immune system. (p. 511)

psychopathology The scientific study of the origins, symptoms, and development of psychological disorders. (p. 535)

psychosexual stages In Freud’s theory, age-related developmental periods in which the child’s sexual urges are focused on different areas of the body and are expressed through the activities associated with those areas. (p. 421)

psychotherapy The treatment of emotional, behavioral, and interpersonal problems through the use of psychological techniques designed to encourage understanding of problems and modify troubling feelings, behaviors, or relationships. (p. 586)

psychotropic medications (sy-ko-TRO-pick) Drugs that alter mental functions, alleviate psychological symptoms, and are used to treat psychological or mental disorders. (p. 614)

puberty The stage of adolescence in which an individual reaches sexual maturity and becomes physiologically capable of sexual reproduction. (p. 386)

punishment The presentation of a stimulus or event following a behavior that acts to decrease the likelihood of the behavior being repeated. (p. 200)

pupil The opening in the middle of the iris that changes size to let in different amounts of light. (p. 91)

R

random assignment The process of assigning participants to experimental conditions so that all participants have an equal chance of being assigned to any of the conditions or groups in the study. (p. 26)

random selection Process in which subjects are selected randomly from a larger group such that every group member has an equal chance of being included in the study. (p. 23)

range A measure of variability; the highest score in a distribution minus the lowest score. (p. A-5)

rational-emotive behavior therapy (REBT) A type of cognitive therapy, developed by psychologist Albert Ellis, that focuses on changing the client’s irrational beliefs. (p. 599)

reality principle The capacity to accommodate external demands by postponing gratification until the appropriate time or circumstances exist. (p. 418)

recall A test of long-term memory that involves retrieving information without the aid of retrieval cues; also called free recall. (p. 240)

reciprocal determinism A model proposed by psychologist Albert Bandura that explains human functioning and personality as caused by the interaction of behavioral, cognitive, and environmental factors. (p. 433)

recognition A test of long-term memory that involves identifying correct information out of several possible choices. (p. 240)

G-13

reinforcement The occurrence of a stimulus or event following a response that increases the likelihood of that response being repeated. (p. 198)

reliability The ability of a test to produce consistent results when administered on repeated occasions under similar conditions. (p. 295)

REM rebound A phenomenon in which a person who is deprived of REM sleep greatly increases the amount of time spent in REM sleep at the first opportunity to sleep without interruption. (p. 147)

REM sleep Type of sleep during which rapid eye movements (REM) and dreaming usually occur and voluntary muscle activity is suppressed; also called active sleep or paradoxical sleep. (p. 140)

replicate To repeat or duplicate a scientific study in order to increase confidence in the validity of the original findings. (p. 18)

representative sample A selected segment that very closely parallels the larger population being studied on relevant characteristics. (p. 23)

representativeness heuristic A strategy in which the likelihood of an event is estimated by comparing how similar it is to the prototype of the event. (p. 283)

repression Motivated forgetting that occurs unconsciously; a memory that is blocked and unavailable to consciousness. (p. 247)

repression (in psychoanalytic theory of personality and psychotherapy) The unconscious exclusion of anxiety-provoking thoughts, feelings, and memories from conscious awareness; the most fundamental ego defense mechanism. (p. 420)

resistance In psychoanalysis, the patient’s unconscious attempts to block the revelation of repressed memories and conflicts. (p. 589)

resting potential The state in which a neuron is prepared to activate and communicate its message if it receives sufficient stimulation. (p. 44)

reticular formation (reh-TICK-you-ler) A network of nerve fibers located in the center of the medulla that helps regulate attention, arousal, and sleep; also called the reticular activating system. (p. 66)

retina (RET-in-uh) A thin, light-sensitive membrane, located at the back of the eye, that contains the sensory receptors for vision. (p. 93)

retrieval The process of recovering information stored in memory so that we are consciously aware of it. (pp. 229, 238)

retrieval cue A clue, prompt, or hint that helps trigger recall of a given piece of information stored in long-term memory. (p. 238)

retrieval cue failure The inability to recall long-term memories because of inadequate or missing retrieval cues. (p. 238)

retroactive interference Forgetting in which a new memory interferes with remembering an old memory; backward-acting memory interference. (p. 247)

retrograde amnesia Loss of memory, especially for episodic information; backward-acting amnesia. (p. 260)

reuptake The process by which neurotransmitter molecules detach from a post-synaptic neuron and are reabsorbed by a presynaptic neuron so they can be recycled and used again. (p. 48)

rods The long, thin, blunt sensory receptors of the eye that are highly sensitive to light, but not to color, and that are primarily responsible for peripheral vision and night vision. (p. 93)

Rorschach Inkblot Test A projective test using inkblots, developed by Swiss psychiatrist Hermann Rorschach in 1921. (p. 442)

S

sample A selected segment of the population used to represent the group that is being studied. (p. 23); a subset of a population. (p. A-12)

saturation The property of color that corresponds to the purity of the light wave. (p. 95)

scatter diagram or scatter plot A graph that represents the relationship between two variables. (p. A-8)

schedule of reinforcement The delivery of a reinforcer according to a preset pattern based on the number of responses or the time interval between responses. (p. 207)

schema (SKEE-muh) An organized cluster of information about a particular topic. (p. 250)

schizophrenia A psychological disorder in which the ability to function is impaired by severely distorted beliefs, perceptions, and thought processes. (p. 569)

scientific method A set of assumptions, attitudes, and procedures that guide researchers in creating questions to investigate, in generating evidence, and in drawing conclusions. (p. 15)

script A schema for the typical sequence of an everyday event. (p. 250)

seasonal affective disorder (SAD) A mood disorder in which episodes of depression typically occur during the fall and winter and subside during the spring and summer. (p. 551)

secondary sex characteristics Sexual characteristics that develop during puberty and are not directly involved in reproduction but differentiate between the sexes, such as male facial hair and female breast development. (p. 387)

selection device validity The extent to which a personnel selection device is successful in distinguishing between those who will become high performers at a certain job and those who will not. (p. B-5)

selective serotonin reuptake inhibitors (SSRIs) Class of antidepressant medications that increase the availability of serotonin in the brain and cause fewer side effects than earlier antidepressants; they include Prozac, Paxil, and Zoloft. (p. 619)

self-actualization Defined by Maslow as a person’s “full use and exploitation of talents, capacities, and potentialities.” (p. 333)

self-concept The set of perceptions and beliefs that you hold about yourself. (p. 429)

self-determination theory (SDT) Deci and Ryan’s theory that optimal human functioning can occur only if the psychological needs for autonomy, competence, and relatedness are satisfied. (p. 333)

self-efficacy The beliefs that people have about their ability to meet the demands of a specific situation; feelings of self-confidence. (pp. 351, 434)

self-report inventory A type of psychological test in which a person’s responses to standardized questions are compared to established norms. (p. 444)

self-serving bias The tendency to attribute successful outcomes of one’s own behavior to internal causes and unsuccessful outcomes to external, situational causes. (p. 461)

semantic memory Category of long-term memory that includes memories of general knowledge, concepts, facts, and names. (p. 236)

semantic network model A model that describes units of information in long-term memory as being organized in a complex network of associations. (p. 238)

sensation The process of detecting a physical stimulus, such as light, sound, heat, or pressure. (p. 86)

sensation seeking The degree to which an individual is motivated to experience high levels of sensory and physical arousal associated with varied and novel activities. (p. 316)

sense of self An individual’s unique sense of identity that has been influenced by social, cultural, and psychological experiences; your sense of who you are in relation to other people. (p. 454)

sensorimotor stage In Piaget’s theory, the first stage of cognitive development, from birth to about age 2; the period during which the infant explores the environment and acquires knowledge through sensing and manipulating objects. (p. 380)

G-14

sensory adaptation The decline in sensitivity to a constant stimulus. (p. 88)

sensory memory The stage of memory that registers information from the environment and holds it for a very brief period of time. (p. 229)

sensory neuron The type of neuron that conveys information to the brain from specialized receptor cells in sense organs and internal organs. (p. 43)

sensory receptors Specialized cells unique to each sense organ that respond to a particular form of sensory stimulation. (p. 87)

serial position effect The tendency to remember items at the beginning and end of a list better than items in the middle. (p. 240)

serotonin (ser-uh-TONE-in) Neurotransmitter involved in sensory perceptions, sleep, and emotions. (p. 51)

set-point theory Theory that proposes that humans and other animals have a natural or optimal body weight, called the set-point weight, that the body defends from becoming higher or lower by regulating feelings of hunger and body metabolism. (p. 320)

sex chromosomes Chromosomes, designated as X or Y, that determine biological sex; the 23rd pair of chromosomes in humans. (p. 361)

sexual orientation The direction of a person’s emotional and erotic attraction toward members of the opposite sex, the same sex, or both sexes. (p. 327)

shape constancy The perception of a familiar object as maintaining the same shape regardless of the image produced on the retina. (p. 122)

shaping The operant conditioning procedure of selectively reinforcing successively closer approximations of a goal behavior until the goal behavior is displayed. (p. 206)

short-term dynamic therapies Type of psychotherapy that is based on psychoanalytic theory but differs in that it is typically time-limited, has specific goals, and involves an active, rather than neutral, role for the therapist. (p. 589)

short-term memory The active stage of memory in which information is stored for up to about 20 seconds. (p. 229)

situational (contingency) theories of leadership Leadership theories claiming that various situational factors influence a leader’s effectiveness. (p. B-9)

Sixteen Personality Factor Questionnaire (16PF) A self-report inventory developed by Raymond Cattell that generates a personality profile with ratings on 16 trait dimensions. (p. 445)

size constancy The perception of an object as maintaining the same size despite changing images on the retina. (p. 121)

skewed distribution An asymmetrical distribution; more scores occur on one side of the distribution than on the other. In a positively skewed distribution, most of the scores are low scores; in a negatively skewed distribution, most of the scores are high scores. (p. A-3)

sleep disorders Serious and consistent sleep disturbances that interfere with daytime functioning and cause subjective distress. (p. 153)

sleep paralysis A temporary condition in which a person is unable to move upon awakening in the morning or during the night. (p. 141)

sleep spindles Short bursts of brain activity that characterize stage 2 NREM sleep. (p. 142)

sleep terrors A sleep disturbance characterized by an episode of increased physiological arousal, intense fear and panic, frightening hallucinations, and no recall of the episode the next morning; typically occurs during stage 3 or stage 4 NREM sleep; also called night terrors. (p. 154)

sleep thinking Vague, bland, thoughtlike ruminations about real-life events that typically occur during NREM sleep; also called sleep mentation. (p. 147)

sleep-related eating disorder (SRED) A sleep disorder in which the sleeper will sleepwalk and eat compulsively. (p. 154)

sleepsex A sleep disorder involving abnormal sexual behaviors and experiences during sleep; also called sexsomnia. (p. 154)

sleepwalking A sleep disturbance characterized by an episode of walking or performing other actions during stage 3 or stage 4 NREM sleep; also called somnambulism. (p. 154)

social anxiety disorder An anxiety disorder involving the extreme and irrational fear of being embarrassed, judged, or scrutinized by others in social situations. (p. 545)

social categorization The mental process of categorizing people into groups (or social categories) on the basis of their shared characteristics. (p. 456)

social cognition The mental processes people use to make sense of their social environments. (p. 454)

social cognitive theory Albert Bandura’s theory of personality, which emphasizes the importance of observational learning, conscious cognitive processes, social experiences, self-efficacy beliefs, and reciprocal determinism. (p. 433)

social influence The effect of situational factors and other people on an individual’s behavior. (p. 454)

social learning theory of gender-role development The theory that gender roles are acquired through the basic processes of learning, including reinforcement, punishment, and modeling. (p. 376)

social norms The “rules,” or expectations, for appropriate behavior in a particular social situation. (p. 454)

social psychology Branch of psychology that studies how a person’s thoughts, feelings, and behavior are influenced by the presence of other people and by the social and physical environment. (p. 454)

social support The resources provided by other people in times of need. (p. 519)

somatic nervous system The subdivision of the peripheral nervous system that communicates sensory information to the central nervous system and carries motor messages from the central nervous system to the muscles. (p. 55)

source confusion A memory distortion that occurs when the true source of the memory is forgotten. (p. 249)

source memory or source monitoring Memory for when, where, and how a particular experience or piece of information was acquired. (p. 247)

source traits The most fundamental dimensions of personality; the broad, basic traits that are hypothesized to be universal and relatively few in number. (p. 437)

specific phobia An excessive, intense, and irrational fear of a specific object, situation, or activity that is actively avoided or endured with marked anxiety. (p. 545)

spinal reflexes Simple, automatic behaviors that are processed in the spinal cord. (p. 55)

split-brain operation A surgical procedure that involves cutting the corpus callosum. (p. 74)

spontaneous recovery The reappearance of a previously extinguished conditioned response after a period of time without exposure to the conditioned stimulus. (p. 187)

stage model of memory A model describing memory as consisting of three distinct stages: sensory memory, short-term memory, and long-term memory. (p. 229)

standard deviation A measure of variability; expressed as the square root of the sum of the squared deviations around the mean divided by the number of scores in the distribution. (p. A-6)

standard normal curve or standard normal distribution A symmetrical distribution forming a bell-shaped curve in which the mean, median, and mode are all equal and fall in the exact middle. (p. A-7)

G-15

standardization The administration of a test to a large, representative sample of people under uniform conditions for the purpose of establishing norms. (p. 294)

statistically significant A mathematical indication that research results are not very likely to have occurred by chance. (p. 18)

statistics A branch of mathematics used by researchers to organize, summarize, and interpret data. (pp. 18, A-2)

stem cells Undifferentiated cells that can divide and give rise to cells that can develop into any one of the body’s different cell types. (p. 364)

stereotype A cluster of characteristics that are associated with all members of a specific social group, often including qualities that are unrelated to the objective criteria that define the group. (p. 466)

stereotype threat A psychological predicament in which fear that you will be evaluated in terms of a negative stereotype about a group to which you belong creates anxiety and self-doubt, lowering performance in a particular domain that is important to you. (p. 304)

stimulants A category of psychoactive drugs that increase brain activity, arouse behavior, and increase mental alertness. (p. 170)

stimulus control therapy Insomnia treatment involving specific guidelines to create a strict association between the bedroom and rapid sleep onset. (p. 176)

stimulus discrimination The occurrence of a learned response to a specific stimulus but not to other, similar stimuli. (p. 186)

stimulus generalization The occurrence of a learned response not only to the original stimulus but to other, similar stimuli as well. (p. 186)

stimulus threshold The minimum level of stimulation required to activate a particular neuron. (p. 44)

storage The process of retaining information in memory so that it can be used at a later time. (p. 229)

stress A negative emotional state occurring in response to events that are perceived as taxing or exceeding a person’s resources or ability to cope. (p. 499)

stressors Events or situations that are perceived as harmful, threatening, or challenging. (p. 501)

structural plasticity The brain’s ability to change its physical structure in response to learning, active practice, or environmental influences. (p. 63)

structuralism Early school of psychology that emphasized studying the most basic components, or structures, of conscious experiences. (p. 4)

sublimation An ego defense mechanism that involves redirecting sexual urges toward productive, socially acceptable, nonsexual activities; a form of displacement. (p. 420)

subliminal perception The detection of stimuli that are below the threshold of conscious awareness; nonconscious perception. (p. 89)

substance P A neurotransmitter that is involved in the transmission of pain messages to the brain. (p. 107)

substantia nigra (sub-STAN-she-uh NYE-gruh) An area of the midbrain that is involved in motor control and contains a large concentration of dopamine-producing neurons. (p. 66)

superego In Freud’s theory, the partly conscious, self-evaluative, moralistic component of personality that is formed through the internalization of parental and societal rules. (p. 418)

suppression Motivated forgetting that occurs consciously; a deliberate attempt to not think about and remember specific information. (p. 247)

suprachiasmatic nucleus (SCN) (soup-ruh-kye-az-MAT-ick) A cluster of neurons in the hypothalamus in the brain that governs the timing of circadian rhythms. (p. 138)

surface traits Personality characteristics or attributes that can easily be inferred from observable behavior. (p. 437)

survey A questionnaire or interview designed to investigate the opinions, behaviors, or characteristics of a particular group. (p. 23)

symbolic thought The ability to use words, images, and symbols to represent the world. (p. 381)

symmetrical distribution A distribution in which scores fall equally on both sides of the graph. The normal curve is an example of a symmetrical distribution. (p. A-4)

sympathetic nervous system The branch of the autonomic nervous system that produces rapid physical arousal in response to perceived emergencies or threats. (p. 57)

synapse (SIN-aps) The point of communication between two neurons. (p. 47)

synaptic gap (sin-AP-tick) The tiny space between the axon terminal of one neuron and the dendrite of an adjoining neuron. (p. 47)

synaptic transmission (sin-AP-tick) The process through which neurotransmitters are released by one neuron, cross the synaptic gap, and affect adjoining neurons. (p. 48)

synaptic vesicles (sin-AP-tick VESS-ick-ullz) The tiny pouches or sacs in axon terminals that contain chemicals called neurotransmitters. (p. 48)

systematic desensitization A type of behavior therapy in which phobic responses are reduced by pairing relaxation with a series of mental images or real-life situations that the person finds progressively more fear-provoking; based on the principle of counterconditioning. (p. 594)

T

t test Test used to establish whether the means of two groups are statistically different from each other. (p. A-11)

taste aversion A classically conditioned dislike for and avoidance of a particular food that develops when an organism becomes ill after eating the food. (p. 193)

taste buds The specialized sensory receptors for taste that are located on the tongue and inside the mouth and throat. (p. 104)

telomeres Repeated, duplicate DNA sequences that are found at the very tips of chromosomes and that protect the chromosomes’ genetic data during cell division. (p. 509)

temperament Inborn predispositions to consistently behave and react in a certain way. (p. 369)

temporal lobe An area on each hemisphere of the cerebral cortex, near the temples, that is the primary receiving area for auditory information. (p. 69)

teratogens Harmful agents or substances that can cause malformations or defects in an embryo or fetus. (p. 364)

testing effect The finding that practicing retrieval of information from memory produces better retention than restudying the same information for an equivalent amount of time. (p. 28)

thalamus (THAL-uh-muss) A forebrain structure that processes sensory information for all senses except smell, relaying that information to the cerebral cortex. (p. 71)

Thematic Apperception Test (TAT) A projective personality test, developed by Henry Murray and colleagues, that involves creating stories about ambiguous scenes. (pp. 334, 442)

theory A tentative explanation that tries to integrate and account for the relationship of various findings and observations. (p. 19)

thinking The manipulation of mental representations of information in order to draw inferences and conclusions. (p. 273)

timbre (TAM-ber) The distinctive quality of a sound, determined by the complexity of the sound wave. (p. 99)

tip-of-the-tongue (TOT) experience A memory phenomenon that involves the sensation of knowing that specific information is stored in long-term memory, but being temporarily unable to retrieve it. (p. 239)

G-16

token economy A form of behavior therapy in which the therapeutic environment is structured to reward desired behaviors with tokens or points that may eventually be exchanged for tangible rewards. (p. 598)

top-down processing Information processing that emphasizes the importance of the observer’s knowledge, expectations, and other cognitive processes in arriving at meaningful perceptions; analysis that moves from the whole to the parts; also called conceptually driven processing. (p. 110)

trait A relatively stable, enduring predisposition to consistently behave in a certain way. (p. 435)

trait approach to leader effectiveness An approach to determining what makes an effective leader that focuses on the personal characteristics displayed by successful leaders. (p. B-8)

trait theory A theory of personality that focuses on identifying, describing, and measuring individual differences in behavioral predispositions. (p. 435)

tranquilizers Depressant drugs that relieve anxiety. (p. 169)

transduction The process by which a form of physical energy is converted into a coded neural signal that can be processed by the nervous system. (p. 87)

transference In psychoanalysis, the process by which emotions and desires originally associated with a significant person in the patient’s life, such as a parent, are unconsciously transferred onto the psychoanalyst. (p. 589)

transgender Condition in which a person’s psychological gender identity conflicts with his or her biological sex. (p. 379)

trial and error A problem-solving strategy that involves attempting different solutions and eliminating those that do not work. (p. 277)

triarchic theory of intelligence Robert Sternberg’s theory that there are three distinct forms of intelligence: analytic, creative, and practical. (p. 300)

trichromatic theory of color vision The theory that the sensation of color results because cones in the retina are especially sensitive to red light (long wavelengths), green light (medium wavelengths), or blue light (short wavelengths). (p. 96)

two-factor theory of emotion Schachter and Singer’s theory that emotion is the interaction of physiological arousal and the cognitive label that we apply to explain the arousal. (p. 350)

Type A behavior pattern A behavioral and emotional style characterized by a sense of time urgency, hostility, and competitiveness. (p. 517)

Type I error Erroneously concluding that study results are significant. (p. A-12)

Type II error Failing to find a significant effect that does, in fact, exist. (p. A-12)

U

unconditional positive regard In Rogers’s theory, the sense that you will be valued and loved even if you don’t conform to the standards and expectations of others; unconditional love or acceptance. (p. 431)

unconditioned response (UCR) The unlearned, reflexive response that is elicited by an unconditioned stimulus. (p. 185)

unconditioned stimulus (UCS) The natural stimulus that reflexively elicits a response without the need for prior learning. (p. 185)

unconscious In Freud’s theory, a term used to describe thoughts, feelings, wishes, and drives that are operating below the level of conscious awareness. (p. 417)

V

validity The ability of a test to measure what it is intended to measure. (p. 295)

variable A factor that can vary, or change, in ways that can be observed, measured, and verified. (p. 16)

variable-interval (VI) schedule A reinforcement schedule in which a reinforcer is delivered for the first response that occurs after an average time interval, which varies unpredictably from trial to trial. (p. 208)

variable-ratio (VR) schedule A reinforcement schedule in which a reinforcer is delivered after an average number of responses, which varies unpredictably from trial to trial. (p. 208)

vestibular sense (vess-TIB-you-ler) The technical name for the sense of balance, or equilibrium. (p. 109)

W

wavelength The distance from one wave peak to another. (p. 91)

Weber’s law (VAY-berz) A principle of sensation that holds that the size of the just noticeable difference will vary depending on its relation to the strength of the original stimulus. (p. 88)

withdrawal symptoms Unpleasant physical reactions, combined with intense drug cravings, that occur when a person abstains from a drug on which he or she is physically dependent. (p. 164)

working memory The temporary storage and active, conscious manipulation of information needed for complex cognitive tasks, such as reasoning, learning, and problem solving. (p. 233)

Z

z score A number, expressed in standard deviation units, that shows a score’s deviation from the mean. (p. A-7)

zone of proximal development In Vygotsky’s theory of cognitive development, the difference between what children can accomplish on their own and what they can accomplish with the help of others who are more competent. (p. 385)

zygote The single cell formed at conception from the union of the egg cell and sperm cell. (p. 360)