2D:4D ratio
A relation between two finger lengths (the second and fourth digit of the hand) that is related to variations in sexual orientation. (p. 150)
accommodation
In Piagetian theory, a cognitive process in which a schema is modified as response to feedback from the environment. (p. 604)
acquisition
In the psychology of learning, attaining the ability to perform a new response; “acquiring” a response. (p. 266)
action potentials
Nerve impulses (or spikes); electrochemical events in which an electrical current travels down the length of an axon. (p. 107)
activation-synthesis theory
A theory about the processes through which dreams are generated, claiming that dreams are the brain’s attempt to make sense of random brain signals. (p. 389)
actual self
People’s perceptions of psychological qualities they possess currently, in the present. (p. 566)
ad hoc categories
Categories whose structure is defined according to the relevance of items to a goal; items in the category are useful for some common purpose. (p. 312)
addictions
Psychological disorders in which people use a drug or engage in an activity repeatedly and uncontrollably. (p. 495)
adolescence
The period between childhood and adulthood; roughly the teenage years. (p. 635)
adrenal glands
Endocrine glands that produce hormones that respond to stress, as well as sex hormones. (p. 115)
affective systems
In social-cognitive theory, psychological systems that generate moods and emotional states. (p. 584)
agoraphobia
Fear of being in diverse social situations outside one’s home, such as in stores, public transportation, or among crowds. (p. 693)
alcohol
A depressant chemical compound found in beer, wine, and spirits that induces feelings of relaxation and a lessening of inhibitions. (p. 401)
alleles
Variations in specific genes that produce different versions of a characteristic, such as eye color or blood type. (p. 134)
alternative hypothesis
A hypothesis stating that a relationship will exist between observed variables; also known as the research hypothesis. (p. A-17)
Ames room
An apparatus for studying the perception of size; the room is not cubic, contrary to the visual system’s assumption, and this creates perceptual illusion involving size. (p. 165)
amphetamines
Stimulants that strongly increase alertness and produce euphoric feelings. (p. 400)
amygdala
A limbic system structure that contributes to the processing of threatening stimuli. (p. 92)
anal stage
In Freud’s theory of psychological development, the developmental stage (18 months to 3½ years) during which children experience gratification from the release of tension resulting from the control and elimination of feces. (p. 558)
anchoring-and-adjustment heuristic
A psychological process in which people formulate estimates by starting with an initial guess (an “anchor”) and adjusting it to reach a final judgment. (p. 333)
anorexia nervosa
Eating disorder characterized by such a fear of being fat that people severely restrict their intake to the point of starvation. (p. 463)
anti-anxiety drugs
Pharmaceuticals designed to alter brain functioning by affecting neurotransmitters in a manner that reduces feelings of anxiety. (p. 689)
anticonvulsants
Drugs typically used to treat epileptic seizures but that also are used to reduce bipolar symptoms. (p. 687)
antipsychotic drugs
Medications designed to alter neurotransmitter activity in the brain in a manner that reduces psychotic symptoms. (p. 719)
antisocial personality disorder
A psychological disorder defined by a set of negative personality traits such as being manipulative, callous, hostile; taking risks; and lacking empathy. (p. 724)
anxiety
An agitated emotional state that includes feelings of apprehension about impending danger or misfortune. (p. 688)
anxiety disorders
Long-lasting psychological states involving strong and persistent feelings of anxiety that interfere with everyday life. (p. 688)
anxious-ambivalent attachment
An attachment style in which an infant experiences conflicting emotions: a desire for closeness with the mother combined with worry and anger toward the parent. (p. 623)
aphasia
An impairment of language abilities that occurs while other mental abilities remain intact. (p. 321)
appraisal theories of emotion
Theories claiming that emotions arise from a psychological process in which people continuously monitor the relation between themselves and the world around them, with these appraisals determining the emotion they experience. (p. 423)
appraisals
Evaluations of the personal significance of ongoing and upcoming events. (p. 423)
approach motivation
A broad class of motives that concern the growth and enhancement of an organism, from obtaining food to attaining a higher social status. (p. 493)
assimilation
In Piagetian theory, a cognitive process in which one understands an object or event by incorporating it into a preexisting schema. (p. 604)
association areas
Areas of the cerebral cortex that receive sensory information from other regions of the brain and connect it to memories and stored knowledge, enabling psychologically meaningful experiences. (p. 97)
attachment
A strong emotional bond between two people, especially a child and a caretaker, such as a parent. (p. 623)
attachment styles
Characteristic ways in which children and parents interact and relate to one another emotionally. (p. 623)
attachment theory
Bowlby’s theory of the ways in which bonds of attachment between parent and child have a lifelong impact on the child. (p. 623)
attention
The process of bringing an idea or an external stimulus into conscious awareness. (p. 204)
attentional effort
Focusing attention on a stimulus in the environment; concentration. (p. 219)
attention-deficit hyperactivity disorder (ADHD)
A condition marked by high distractibility, low ability to concentrate, and impulsive behavior such as fast and frequent moving and talking. (p. 400)
attitude
A combined thought and feeling directed toward some person, object, or idea. (p. 528)
attributions
Beliefs about the causes of social behaviors. (p. 524)
atypical antipsychotics
One of two major types of antipsychotic drugs, specifically, the second class of such drugs to be developed, in the 1990s. Atypical antipsychotics may relieve a wider range of symptoms while having fewer side effects than typical antipsychotics. (p. 719)
auditory cortex
A region of the temporal lobes that contributes to the processing of sounds and also is key to remembering facts and experiences. (p. 96)
auditory nerve
A bundle of nerve cells that carries auditory information from the inner ear to the brain. (p. 189)
auditory system
The perceptual system detecting environmental information that consists of sound waves. (p. 160)
autism
Autism spectrum disorder, a range of symptoms whose central features include impaired communication and social interaction with other people. (p. 611)
autobiographical memory
Your memory of facts and experiences from your own life. (p. 244)
automatic thoughts
Thoughts that spring to mind rapidly and unintentionally. (p. 670)
autonomic nervous system
Functionally, the part of the peripheral nervous system that provides the communications controlling bodily functions that generally are not under your control, such as breathing. (p. 112)
availability heuristic
A psychological process in which people base judgments on the ease with which information comes to mind. (p. 332)
avoidance motivation
A drive to protect oneself from threats and dangers, both physical and social. (p. 493)
avoidant attachment
The attachment style in which a child reacts to a parent in a relatively indifferent manner; the child does not count on the parent as a source of security and comfort. (p. 623)
avoidant personality disorder
A psychological disorder characterized by feelings of social inadequacy, low self-esteem, and preoccupation with potential negative evaluations by others, leading to behavior that is shy, withdrawn, and inhibited. (p. 725)
axon
The thin and long projection from a neuron that sends outgoing signals to other neurons. (p. 107)
back translation
A method to assure the accuracy of translation by having the research materials translated twice (by different individuals)—first into the second language, and then from the second language back into the first. (p. 41)
basic-level categories
Categories that are informative and efficient, and that thus are used most commonly to categorize items. (p. 309)
Beck’s cognitive therapy
A therapy method for changing negative, irrational thoughts by increasing clients’ awareness of their automatic thoughts, challenging those thoughts, and suggesting positive alternative ones. (p. 670)
behavior genetics
Field of study that investigates the degree to which psychological variations are inherited. (p. 127)
behavior therapy
A therapy strategy grounded in research on learning, in which therapists aim to directly alter clients’ patterns of behavior by teaching more adaptive ways of behaving. (p. 667)
behavioral approach system
A neural system activated by stimuli that signal the future presence of rewards, energizing an organism to seek out rewarding stimuli. (p. 493)
behavioral inhibition system
A neural system activated by signals of punishment, increasing levels of arousal and feelings of anxiety. (p. 494)
behaviorism
A school of thought focusing solely on the prediction and control of behavior, by studying how the environment shapes observable actions. (p. 28)
benzodiazepines
Psychoactive drugs prescribed for anxiety that reduce feelings of anxiety while also inducing muscular relaxation and sleepiness; may also produce pleasurable feelings. (p. 400)
Big Five
A set of personality traits that is found consistently when researchers analyze, via factor analysis, people’s descriptions of personality. (p. 573)
binge eating disorder
A pattern of repeatedly eating excessively; binging without purging. (p. 463)
binocular cues
Depth cues that require two eyes. (p. 163)
biological constraint
An evolved predisposition that makes it difficult or impossible for a given species to learn a certain type of behavior when reinforced with a certain type of reward. (p. 293)
biological needs
Necessities required for an organism’s survival (food, drink) and for reproduction. (p. 460)
biological therapies
In the treatment of psychological disorders, interventions that directly alter the biochemistry or anatomy of the nervous system. (p. 665)
biopsychosocial model
A way of explaining developmental events (e.g., behavioral changes at puberty) in which the impact of biology on behavior is said to depend on social experiences. (p. 637)
bipolar disorder (manic-depressive disorder)
A depressive disorder characterized by extreme variations in mood, from severe depression to mania. (p. 686)
blind spot
The location in the visual field at which nothing is seen because light from that location projects to an area of the retina in which there are no photoreceptors; this is the retinal area where the optic nerve exits the eye. (p. 179)
blocking
A failure to learn an association between a conditioned stimulus and an unconditioned stimulus that occurs if other environmental stimuli already predict occurrences of the unconditioned stimulus. (p. 273)
blood–brain barrier
A set of biological mechanisms in the circulatory system that prevents most substances in the bloodstream from entering brain tissue. (p. 677)
borderline personality disorder
A psychological disorder involving an unstable sense of self, emotional instability, unstable interpersonal relationships, and a sense of abandonment. (p. 725)
brain stem
The lowest region of the brain; its structures regulate bodily activities critical to survival. (p. 88)
brief psychotic disorder
A disorder in which people experience symptoms typical of schizophrenia, but for only a brief period of time. (p. 721)
Broca’s area
A region of the frontal lobe in the left hemisphere of the brain needed to produce speech. (p. 321)
bulimia nervosa
Eating disorder characterized by a fluctuating pattern of binging and purging. (p. 463)
caffeine
A chemical compound found in coffee, tea, energy drinks, sodas, and chocolate that increases alertness. (p. 400)
Cannon–Bard theory of emotion
A theory of the generation of emotional states in which emotionally arousing events produce physiological and emotional responses simultaneously, rather than one leading to the other. (p. 437)
case study
A detailed analysis of one particular person or group of people; the person or group is the “case.” (p. 62)
categorize
To classify an item as a type of thing, that is, a member of a group. (p. 308)
category level
A relation between categories; one category is of a lower level than another when all members of the former category are contained within the latter, higher-level category. (p. 309)
category structure
The rules that determine category membership. (p. 310)
central nervous system
The part of the nervous system found in the center of the body; its two main parts are the brain and the spinal cord. (p. 111)
cerebellum
A brain structure located behind the brain stem that regulates motor movement and also contributes to emotion and thinking. (p. 89)
cerebral cortex
A layer of cells on the brain’s outer surface that is key to the human capacity for complex conceptual thought. (p. 94)
cerebral hemispheres
The two sides of the brain; the left hemisphere specializes in analytical tasks including math and language, while the right hemisphere is specialized for spatial thinking, the ability to create and think about images. (p. 99)
child prodigies
Children exhibiting exceptional mastery of a skill at a very early age. (p. 352)
chromosomes
Biological structures within the nucleus of cells that contain genetic information (DNA). (p. 134)
chunking
A strategy for increasing the amount of information retained in short-term memory in which distinct pieces of information are grouped into “chunks.” (p. 246)
circadian rhythm
The approximately 24-hour cycle of changes in internal bodily processes. (p. 382)
clarity
The degree of distinctness, as opposed to fuzziness, of a visual image; a monocular depth cue. (p. 164)
classical categories
Categories whose boundaries are unambiguous due to clear-cut rules for determining category membership. (p. 310)
classical conditioning
A form of learning that occurs when an organism encounters a stimulus that repeatedly signals the occurrence of a second stimulus. (p. 260)
clinical case study
In psychology, an analysis of someone receiving psychological therapy; generally a written summary of a case. (p. 62)
clinical psychologists
Professionals trained not only in principles of psychological science, but also in the application of those principles to the diagnosis of, and provision of therapy for, psychological disorders. (p. 656)
close relationships
One-on-one interactions in which a person is in frequent contact with, and feels a strong connection to, another person. (p. 506)
cocaine
A powerful stimulant that increases alertness and produces euphoric feelings, and thus is highly addictive. (p. 400)
coevolution
Processes through which biology and culture interact in the course of human evolution. (p. 124)
cognitive control
The mental ability to suppress one’s emotions and impulsive behaviors that are undesired or inappropriate. (p. 634)
cognitive development
Growth in intellectual capabilities, particularly during the early years of life. (p. 602)
cognitive dissonance
A negative psychological state that occurs when people recognize that two (or more) of their ideas or actions do not fit together sensibly. (p. 528)
cognitive impairments (in schizophrenia)
Among people with schizophrenia, reduced ability to perform everyday thinking tasks such as concentrating, remembering, and planning social interactions. (p. 706)
cognitive revolution
A school of thought focusing on the mind as an information-processing system; in so doing, it introduced novel forms of theory and research into psychological science. (p. 30)
cognitive therapy
A psychological therapy in which therapists try to improve mental health by changing the way in which clients think, reducing negative, self-defeating thoughts. (p. 669)
Cohen’s d
A measure of effect size that expresses the difference between sample means in standard deviation units. (p. A-24)
collective unconscious
Jung’s concept of a storehouse of mental images, symbols, and ideas that all humans inherit thanks to evolution. (p. 562)
collectivistic
In the study of cultural variations, a pattern of cultural beliefs and values that emphasizes individuals’ ties to larger groups such as family, community, and nation. (p. 540)
color blindness
An insensitivity to one or more of the colors red, green, or blue. (p. 176)
color constancy
The tendency for a given object to be perceived as having the same color, despite changes in illumination. (p. 173)
community-participation study
A type of research in which researchers collaborate with community residents to determine a study’s goals and research procedures. (p. 62)
comorbidity
The presence of symptoms of two or more disorders in any one individual. (p. 662)
compensation
In the selection, optimization, and compensation (SOC) model of successful aging, the identification of alternative strategies to achieve goals, if at first you don’t succeed. (p. 643)
compensatory response
A biological reaction to a conditioned stimulus that is the opposite of the effects of the stimulus and therefore partially counteracts its effects. (p. 271)
compliance
Agreement to an explicit request. (p. 513)
concrete operational stage
In Piaget’s theory of child development, the stage (ages 7 to 11) in which children can perform reversible logical operations (e.g., basic arithmetic) limited to “concrete” objects that actually exist. (p. 606)
condition of worth
In Rogers’s theory of personality, a behavioral requirement imposed by others, such as parents, as a condition for being fully valued, loved, and respected. (p. 567)
conditioned response (CR)
A response to a conditioned stimulus that occurs as a result of learning through classical conditioning. (p. 262)
conditioned stimulus (CS)
An event that elicits a response from an organism only after the organism learns to associate it with another stimulus that already evokes a response. (p. 262)
conditioned taste aversion (Garcia effect)
The rapid learning of a connection between the taste of a food and illness that occurs after consuming that food. (p. 275)
cones
Photoreceptors that are concentrated near the center of the retina and that provide visual detail and color. (p. 176)
confederate
In a research study, an accomplice of the experimenter who pretends to be a participant. (p. 512)
confirmation bias
The tendency to seek out information that is consistent with one’s initial conclusions, and to disregard information that might contradict those conclusions. (p. 328)
conformity
The altering of one’s behavior so that it matches the norms of a group. (p. 510)
confound
A factor other than the independent variable that might create differences between experimental conditions. (p. 49)
connectome
The complete network of neural connections in the brain and overall nervous system of an organism. (p. 104)
conscious
In Freud’s analysis of levels of consciousness, the regions of mind containing the mental contents of which you are aware at any given moment. (p. 555)
consciousness
Awareness and personal experience of oneself and one’s surroundings. (p. 362)
consent procedure
A process in which researchers describe a study’s procedures and determine whether participants agree to take part. (p. 73)
conservation
In Piagetian psychology, the recognition that an object maintains some of its essential physical properties even when it is physically transformed. (p. 606)
consolidation
A transformation of information in long-term memory from a fragile state, in which information can be lost, to a more fixed state in which it is available relatively permanently. (p. 230)
control group
An experimental condition that does not receive the experimental treatment. (p. 48)
convergence
A binocular depth cue based on the effort eye muscles must exert to look at objects very close to the face. (p. 167)
converging vertical lines
A monocular depth cue consisting of vertically oriented lines that get closer to one another, creating the perception of depth. (p. 163)
conversion disorder
A psychological disorder characterized by physical symptoms (e.g., partial paralysis, difficulty seeing or hearing) that cannot be explained by a medical condition. (p. 739)
cornea
The transparent material at the very front of the eye; its curvature begins the process of focusing light. (p. 175)
corpus callosum
A brain structure that connects the two hemispheres of the brain, enabling them to work in synchrony. (p. 99)
correlation coefficient (correlation)
A numerical value that represents the strength of a correlation between any two variables. (p. 44; see also pp. A-11, A-12)
correlational study
A research design whose aim is to determine the relation between two or more measured variables. (p. 43)
counseling psychologists
Professionals whose training and professional activities are similar to those of clinical psychologists, but with particular emphasis on the provision of advice regarding not only mental health, but also personal and vocational development. (p. 656)
cranial nerves
Those parts of the peripheral nervous system found in the head; nerves that extend from the bottom of the brain to structures in the head such as eyes, nose, and tongue. (p. 112)
criterion variable
In a correlation between two variables, the variable whose value is predicted by the other (predictor) variable. (p. A-12)
critical period
For a given psychological process, a span of time early in life during which a psychological process must occur if it is ever to develop. (p. 622)
critical thinking
Thinking skills that include the ability to think logically, to question assumptions, to evaluate evidence, and, generally, to be open-minded yet skeptical. (p. 12)
cross-cultural study
Research in which identical research procedures are carried out in different cultures. (p. 540)
crowds
Large gatherings of people who do not necessarily know one another. (p. 506)
cues to depth
Sources of information that enable us to judge the distance between ourselves and the objects we perceive. (p. 163)
cultural psychology
Branch of psychology that studies how the social practices of cultures and the psychological qualities of individuals mutually influence one another. (p. 539)
culture
People’s shared beliefs and the social practices that reflect those beliefs. (p. 538)
cutaneous receptors
Receptor cells under the skin that convert physical stimulation into nervous-system impulses. (p. 200)
data
Any type of information obtained in a scientific study. (p. 51)
decay
The fading of information from short-term memory. (p. 221)
decision making
The process of making a choice, that is, selecting among alternatives. (p. 334)
defense mechanism
A mental strategy that, in psychoanalytic theory, is devised by the ego to protect against anxiety. (p. 559)
delusional beliefs
Personal convictions that contradict known facts about the world but that a person clings to even when faced with conflicting evidence. (p. 706)
delusional disorder
A psychological disorder in which people hold convictions that contradict known facts (e.g., that someone is trying to harm them). (p. 721)
dendrites
Projections that branch out from the main body of a neuron, receiving incoming signals from other neurons. (p. 107)
deoxyribonucleic acid (DNA)
The molecule found in chromosomes that encodes the instructions for building an organism. (p. 134)
dependent variable
In an experimental design, the variable that is potentially influenced by the manipulation of the independent variable. (p. 47)
depersonalization/derealization disorder
A psychological disorder in which people feel detachment from their own experiences; key symptoms are depersonalization (a sense of merely observing with detachment) and derealization (feeling as if objects and others are unreal or foggy). (p. 735)
depressants
Psychoactive drugs that reduce arousal in the central nervous system, lowering conscious experiences of excitability and anxiety. (p. 400)
depression
A family of psychological disorders that includes feelings of sadness and hopelessness, fatigue, loss of interest in activities, changes in eating and sleeping patterns, and that continues for weeks. (p. 680)
depth of processing
The degree to which people think about meaningful rather than superficial aspects of presented information. (p. 224)
depth perception
The perception of distance. (p. 163)
descriptive statistics
Mathematical techniques geared toward summarizing data. (p. A-1)
developmental psychology
The field of study that explores the ways people change, and remain the same, across the course of life. (p. 602)
developmental stage
In Piaget’s theory of child development, a period of months or years during which one form of given thinking is predominant. (p. 605)
Diagnostic and Statistical Manual of Mental Disorders (DSM)
Reference book that comprehensively lists and classifies mental disorders, specifying diagnostic criteria. (p. 661)
dialectical behavior therapy
A therapy for borderline personality disorder whose core element is a dialectic approach that attempts to identify and reconcile opposing points of view on psychological problems, in an effort to reduce emotional distress. (p. 732)
differentiated self-esteem
The varying feelings people may have about themselves when thinking about different aspects of their lives. (p. 633)
diffusion of responsibility
Lowered feelings of personal obligation to respond to someone in need, because others might respond instead. (p. 520)
direct observation
A research method in which researchers view the actions of research participants firsthand and record the behaviors they observe, often by counting specific behaviors. (p. 66)
direct sibling effects
Developmental influence involving one-on-one interactions between siblings. (p. 628)
discrimination
(1) In the study of learning, a process in which organisms distinguish between stimuli, responding to one stimulus but not another. (p. 268); (2) In social psychology, unjust treatment of people based on their group membership. (p. 534)
discriminative stimulus
Any stimulus that provides information about the type of consequences that are likely to follow a given type of behavior in particular situations. (p. 290)
disorganized thinking
A positive symptom of schizophrenia in which thoughts and speech are not properly structured, and speech is thus unintelligible. (p. 706)
disrupt-then-reframe technique
A compliance strategy in which targets of compliance efforts are distracted, so they cannot formulate negative thoughts about a compliance request. (p. 514)
dissociative amnesia
A psychological disorder in which people are unable to remember significant personal information that typically would be highly memorable. (p. 736)
dissociative disorders
Category of psychological disorders characterized by alterations in one’s sense of personal identity, conscious experiences of events, or memory of one’s own past. (p. 733)
dissociative fugue
A psychological disorder featuring complete loss of memory of one’s own personal identity. (p. 736)
dissociative identity disorder
A psychological disorder in which people experience more than one self; that is, more than one personality seems to inhabit their mind. (p. 733)
distal causes
In an evolutionary analysis, factors in the distant past that caused a biological mechanism to evolve. (p. 141)
distal goal
A goal that specifies an achievement in the distant future. (p. 476)
distribution
A set of scores that can be described by the frequency of each score. (p. A-2)
distribution of sample means
A hypothetical distribution of all possible sample means of a given sample size from a specified population. (p. A-18)
dizygotic (DZ) twins
Siblings produced during the same pregnancy who are conceived from two separately fertilized cells; fraternal twins. (p. 122)
dopamine hypothesis of schizophrenia
A hypothesis stating that abnormal levels of dopamine are responsible for the symptoms of schizophrenia. (p. 712)
double-blind clinical outcome study
A research procedure to evaluate the effectiveness of therapy in which neither the research participants nor the researcher interacting with them knows the condition of the experiment to which the participant has been assigned. (p. 680)
drug addiction
Compulsive, habitual, uncontrollable use of a harmful chemical substance. (p. 397)
drug therapies
In the treatment of psychological disorders, treatment with pharmaceuticals that alter the biochemistry of the brain to improve emotional state and thinking abilities. (p. 665)
DSM-5
The current edition of the DSM manual, published in 2013 with substantial changes in content. (p. 662)
dualism
The proposition that the mind and body are two separate entities, with consciousness being a property of the nonphysical mind. (p. 368)
ear
A biological mechanism for hearing with three overall parts: an outer ear, middle ear, and inner ear. (p. 187)
eardrum
A thin membrane within the ear that vibrates when struck by sound waves. (p. 187)
eating disorders
Disturbances in eating in which people lose the ability to control their intake of food, resulting in serious health risks. (p. 462)
echoic memory
Sensory memory for sound. (p. 218)
eclectic therapy (integrative psychotherapy)
Therapy that draws upon any therapeutic method available, with the therapist combining the methods of different therapy schools in designing an optimal approach for therapy in general or an individual client. (p. 674)
ecstasy
A recreational drug that can reduce anxiety and create feelings of intimacy and euphoria while raising body temperature; both a stimulant and a hallucinogen. (p. 400)
EEG
See electroencephalography
effect size
A measure indicating how big an effect is (e.g., how great the difference between two means) that takes into account the consistency of the effect and that ignores sample size. (p. A-23)
ego
In Freud’s psychoanalytic theory, the mental system that balances the demands of the id with the opportunities and constraints of the real world. (p. 554)
electroconvulsive therapy (ECT)
A biological therapy for severe depression in which electrical currents are delivered to the brain. (p. 677)
electroencephalography (EEG)
A technique for recording and visually depicting electrical activity within the brain in which electrodes on the scalp record neural activity in underlying brain regions. The record of electrical activity through this method is called an electroencephalogram. (pp. 67, 381)
embodied cognition
A conceptual model of knowledge representation in which parts of the mind previously thought to participate only in relatively simple mental activities, such as perceiving an event, also contribute to complex thought and memory. (p. 237)
emerging adulthood
The period of life in the late teens and early 20s (roughly 18 to 25) experienced by people who have the rights and psychological independence of adulthood but do not yet have the obligations and responsibilities of family life. (p. 640)
emotion
A psychological state that combines feelings, thoughts, and bodily arousal and that often has a distinctive accompanying facial expression. (p. 409)
empathic understanding
In humanistic therapy, the therapist’s understanding of the client’s psychological life from the perspective of the client. (p. 671)
empirical rule
A rule stating that in a normal distribution, roughly 68% of scores will fall within 1 standard deviation of the mean; 95% will fall within 2 standard deviations; and 99% will fall within 3 standard deviations. (p. A-8)
empirically supported therapies
Treatments whose effectiveness is established in carefully controlled experimental research. (p. 679)
encoding
The process through which information is transferred from sensory memory to short-term memory and, in the transfer, converted from physical stimulation to conceptual information (i.e., ideas). (p. 219)
endocrine system
A collection of glands that produce and secrete hormones, which carry messages from the brain to organs via the bloodstream. (p. 113)
epigenetics
The study of how environmental experience “switches on” genes, making them active in the production of proteins. (p. 136)
episodic memory
Memory for events you have experienced. (p. 229)
ethnic identity
People’s personal identification with the ethnic group to which they belong. (p. 638)
evolution
The biological process through which species develop and change across generations. (p. 140)
evolutionary psychology
Field of study that explores the evolutionary foundations of contemporary human mental abilities, preferences, and desires. (p. 142)
evolved mechanisms
Biological systems that developed over the course of evolution, thanks to their success in solving a specific problem faced repeatedly by members of a given species. (p. 141)
experience sampling method
A research procedure in which participants carry an electronic device throughout the course of a study, signaling the participant to respond at random intervals throughout the day. (p. 488)
experiment
A research design in which a variable is manipulated, with a goal of identifying the causes of events. (p. 47)
experimental conditions
The different settings in a research design, which contain different levels of the independent variable. (p. 48)
experimental design
The researcher’s plan for manipulating one or more variables in an experiment. (p. 47)
explicit measure
An assessment of psychological qualities (e.g., personality characteristics) in which test items directly inquire about the psychological quality of interest, and people’s responses are interpreted as a direct index of those qualities. (p. 589)
explicit memory
Conscious recall of previously encountered information or experience. (p. 229)
exposure and response prevention
A type of therapy for obsessive-compulsive disorder in which therapists cause clients to come into contact with the stimuli that trigger their obsessions while preventing them from engaging in their usual compulsive behavior. (p. 695)
exposure therapy
A behavior therapy technique in which therapists combat the emotions of fear and anxiety by bringing clients into direct contact with an object or situation that arouses their fear, while ensuring that no harm occurs. (p. 668)
extinction
In the study of learning, a gradual lessening of a response that occurs when a stimulus is presented repeatedly without any presentations of an unconditioned stimulus (in classical conditioning) or reinforcer (in operant conditioning). (p. 269)
extinguishing
(of emotion) In exposure therapy, the reduction in emotional response that occurs when an anticipated emotionally arousing consequence does not occur. (p. 668)
eyewitness memory
Memory for events that are personally observed (rather than being learned of second-hand, through conversation or reading). (p. 241)
Facial Action Coding System (FACS)
A method for measuring emotions that capitalizes on the link between emotional experience and facial expression; in this system, researchers code muscular movements occurring in specific parts of the face. (p. 419)
facial feedback hypothesis
The prediction that biological feedback from facial muscles directly influences emotional experience. (p. 417)
factor analysis
A statistical technique that identifies patterns in large sets of correlations. (p. 572)
false memory
The experience of “remembering” an event that, in reality, never occurred. (p. 239)
family resemblance
A category structure in which category members share many features but no single feature is absolutely necessary for membership. (p. 311)
fetishism
Sexual arousal in which stimuli that typically are not sexual in nature stir desires. (p. 465)
fight-or-flight response
A behavioral pattern in which an organism facing a threat does one of two things: attack or flee. (p. 450)
figure-ground perception
The visual system’s tendency to divide a scene into objects, or “figures,” that are the focus of attention and the background context. (p. 172)
fixation
In Freud’s theory of psychological development, a disruption in development occurring when an individual experiences either too little or too much gratification at a psychosexual stage. (p. 559)
fixed schedule of reinforcement
In operant conditioning research, a timetable for reinforcement that is consistent across trials. (p. 287)
flashbulb memory
Vivid memory of unexpected, highly emotional, and significant events. (p. 242)
flat affect
An absence of normal emotional expression; a negative symptom of schizophrenia. (p. 707)
flow
A psychological state in which your attention is directed intently on an activity for a long period of time, and you feel immersed in the activity. (p. 485)
Flynn effect
Name given to the relatively rapid rise in intelligence test scores that is evident across generations. (p. 347)
foot-in-the-door technique
A compliance strategy in which someone first makes a small request, in order to later convince people to comply with a larger request. (p. 513)
foreclosure
According to Marcia, the identity status of people who know their role in life and prospective future occupation, but feel these were imposed on them by others. (p. 637)
formal operational stage
In Piaget’s theory of child development, the stage (age 11 to adulthood) in which children can execute mental operations on both actual objects and hypothetical ones, using abstract rules. (p. 606)
fovea
A region near the center of the retina that features a dense concentration of cones. (p. 176)
framing effect
A phenomenon in decision making in which people’s decisions are affected by the way in which outcomes are described, or “framed.” (p. 335)
free association method
A method of both personality assessment and therapy devised by Freud in which psychologists encourage people to let their thoughts flow freely and say whatever comes to mind. (pp. 561, 665)
frequency
The physical property of sound waves that produces variations in pitch, based on the number of vibrations that occur during any fixed period of time. (p. 184)
frequency distribution table
A table that lists all the scores in a distribution in numeric order, as well as the frequency of each score. (p. A-2)
frequency polygon
A frequency distribution graph that uses dots connected by lines to represent frequency. (p. A-3)
frontal lobes
A part of the cerebral cortex that is particularly large in humans and enables distinctive human mental abilities such as self-reflection (i.e., thinking about oneself). (p. 96)
functional magnetic resonance imaging (fMRI)
A brain-scanning method that depicts activity in specific regions of the brain as people engage in psychological activities. (p. 67)
functionalism
A school of thought focusing on the mental activity of the mind rather than on its structure, as it interacts with the body and adapts to the environment. (p. 27)
fundamental attribution error
Pattern of thinking in which people underestimate the causal influence of situational factors on people’s behavior and overestimate the causal influence of personal factors. (p. 525)
fuzzy categories
Categories whose boundaries are ambiguous. (p. 310)
ganglion cells
Cells that form the optic nerve and pass visual information from the retina to the brain. (p. 179)
Garcia effect
See conditioned taste aversion
gate control theory of pain
The theory that the spinal cord contains a biological mechanism that acts like a gate; when closed, pain signals do not reach the brain, resulting in no experience of pain even though there is pain receptor activity. (p. 202)
gene
Any section of DNA that provides the full information needed to produce a protein. (p. 134)
gene expression
A biological process in which information in DNA becomes active in the process of producing protein molecules. (p. 135)
general adaptation syndrome (GAS)
A sequence of physiological reactions in response to stressors: alarm, resistance, and exhaustion. (p. 444)
general intelligence (g)
A measure of overall mental ability based on total performance across a number of different types of intellectual tests. (p. 344)
generalization
A learning process in which responses are elicited by stimuli that vary slightly from the stimuli encountered during acquisition of a response. (p. 267)
generalized anxiety disorder
A psychological disorder in which people experience high and persistent levels of tension, agitation, apprehension, and worry, even in the absence of a current event that provokes the feelings. (p. 689)
generative
A characteristic of language referring to the fact that linguistic rules enable speakers to produce (or “generate”) an infinite number of sentences. (p. 314)
genital stage
In Freud’s theory of psychological development, the developmental stage that starts at puberty, signaling the reawakening of sexual desire. (p. 558)
genome
The entire set of genes possessed by an organism. (p. 134)
genome-wide association study
A method in which researchers study the relation between a psychological characteristic (e.g., a psychological disorder) and hundreds or thousands of genetic variations simultaneously, in order to identify places along the human genome that are associated with the presence versus absence of the characteristic. (p. 717)
glial cells
Cells that hold neurons in place and also support their biological functioning, supplying nutrients to neurons and disposing of the brain’s biological waste matter. (p. 110)
global self-esteem
A person’s overall sense of self-worth. (p. 633)
goal
A mental representation of the aim of an activity; more simply, goals are thoughts about future outcomes that people value. (p. 475)
gonads
The organs that produce reproductive cells—ovaries in women produce ova and testes in men produce sperm. (p. 115)
group dynamics
Psychological processes involving communication, conflict, and pressure among group members. (p. 510)
group therapy
Any type of psychological therapy in which a therapist meets with two or more clients together. (p. 672)
groups
Collections of people who know and communicate with each other, have distinctive roles (e.g., a group leader), and may work together toward a common goal. (p. 506)
groupthink
A decision-making phenomenon in which group members are so motivated to avoid disagreement, and to reach a shared decision, that they do not properly evaluate the quality of the decision they are reaching. (p. 513)
gustatory cortex
The brain region in the parietal lobe that completes the processing of perceptual signals of taste. (p. 196)
gustatory system
The perceptual system that is sensitive to chemical substances and provides the sense of taste. (p. 160)
habituation
A lessening in response that occurs when a stimulus that normally evokes a reaction in an organism is presented (p. 270)
hair cells
Auditory receptor cells in the inner ear that are responsible for transduction of sound waves. (p. 188)
hallucinations
Experiences (sights, sounds, smells, tastes, or touches) of people or things that are not really there. (p. 706)
hallucinogens
Substances that profoundly alter consciousness, causing people to experience phenomena such as hallucinations and a loss of contact with reality. (p. 398)
haptic system
The perceptual system through which people acquire information about objects by touching them. (p. 160)
hedonic hunger
Hunger that arises from the anticipated pleasure of eating good food. (p. 462)
heritability
The degree to which genetic factors explain individual differences in a characteristic. (p. 129)
heuristic
A rule of thumb, that is, a simple way of accomplishing something that otherwise would be done through a more complex procedure. (p. 331)
heuristic information processing
Thinking that employs mental shortcuts or simple rules of thumb. (p. 528)
hippocampus
A limbic system structure needed for forming permanent memories and central to spatial memory (the recall of geographic layouts). (p. 91)
histogram
A frequency distribution graph in which bars are used to represent the frequency of each score. (p. A-2)
homeostatic hunger
Motivation to eat based on the body’s need for energy. (p. 461)
homeostatic processes
Processes that maintain a stable biological state in an organism. (p. 461)
homunculus problem
A problem in scientific explanation that arises if an organism’s capacity for consciousness is explained by proposing that a structure in its mind or brain is conscious. The problem is the failure to explain how consciousness arises in the mind or brain structure. (p. 370)
hormones
Chemicals that the endocrine system uses for communication; they travel through the bloodstream and carry messages to the body’s organs. (p. 114)
Human Genome Project
An international effort to map the entire sequence of molecular material in the human genetic code; initiated in 1990, the project was completed in 2003. (p. 138)
humanistic psychology
An intellectual movement which argues that everyday personal experiences—thoughts, feelings, hopes, fears, sense of self—should be psychologists’ main target of study. (p. 28)
humanistic theory
An approach to personality that focuses on people’s thoughts and feelings about themselves and the ways that interpersonal relationships shape these feelings. (p. 565)
humanistic therapy
A psychological therapy in which therapists provide clients with supportive interpersonal relationships; the quality of the relationship between therapist and client is key to the client’s growth and change. (p. 671)
hunger
A feeling of food deprivation that motivates organisms to seek food. (p. 460)
hypnosis
An altered state of consciousness characterized by the subject’s unusual responsiveness to suggestions made by the hypnotist. (p. 394)
hypnotic induction
The process of inducing a state of hypnosis in a subject, usually through procedures combining relaxation and focused attention. (p. 394)
hypothalamic–pituitary–adrenal (HPA) axis
An interconnected set of structures and hormone pathways regulating stress response. (p. 444)
hypothalamus
A limbic system structure key to the regulation of bodily states and behaviors such as eating, drinking, and sexual response. (p. 90)
hypothesis
A prediction about the result of a study. (p. 48)
iconic memory
Sensory memory of visual images. (p. 217)
id
In Freud’s psychoanalytic theory, the personality structure that motivates people to satisfy basic bodily needs. (p. 554)
ideal self
People’s perceptions of psychological qualities that they optimally would possess in the future. (p. 566)
identity
People’s overall understanding of themselves, their role in society, their strengths and weaknesses, their history, and their future potential. (p. 637)
identity achievement
According to Marcia, the identity status achieved by people who have deeply contemplated life options and are committed to a career path based on their values. (p. 637)
identity diffusion
According to Marcia, the identity status of people who feel directionless, with no firm sense of where they’re headed in life. (p. 637)
identity statuses
In Marcia’s theory, four different approaches to coping with the challenge of establishing a personal identity. (p. 637)
if…then…profile method
A method for assessing behavior in which researchers chart variations in behavior that occur when people encounter different situations. (p. 590)
immune system
A set of bodily processes that protects against germs, microorganisms, and other foreign substances that enter the body and can cause disease. (p. 446)
implementation intentions
Plans that specify exactly when and where you will work on achieving a goal. (p. 480)
implicit measure
An assessment of psychological qualities (e.g., personality characteristics) that does not rely on test takers’ direct reports of their qualities; instead, measures such as length of time taken to answer a question provide information about psychological qualities. (p. 589)
implicit memory
Task performance that is affected by previous information or experience, even if the prior material is not explicitly remembered. (p. 229)
imprinting
A phenomenon in some species in which newborns fix attention upon, and follow, the first moving object they encounter. (p. 622)
independent variable
In an experimental design, any variable that the experimenter manipulates in order to see its effect on another variable. (p. 47)
indirect sibling effects
Developmental influence in which parents’ interactions with one sibling affect treatment of a second sibling. (p. 628)
individualistic
In the study of cultural variations, a pattern of cultural beliefs and values that emphasizes individual rights to pursue happiness, speak freely, and “be yourself.” (p. 540)
inferential statistics
Mathematical techniques that enable scientists to make inferences about populations based on data collected from samples. (p. A-1)
information-processing system
A device that can acquire, store, and manipulate symbols to transform information. (p. 30)
inhibited temperament
A tendency to experience high levels of distress and fear, especially in unfamiliar situations or in the presence of unfamiliar people. (p. 620)
insight therapy
A type of psychotherapy in which therapists help clients identify and understand the root causes of their psychological symptoms. (p. 665)
insomnia
A sleep disorder involving prolonged difficulty in falling asleep or staying asleep. (p. 386)
instinct
A behavioral tendency possessed by an animal due to its biological inheritance. (p. 317)
Institutional Review Board (IRB)
A group of professionals who assess the ethics of a proposed research study. (p. 72)
integrative psychotherapy
See eclectic therapy
intelligence
The ability to acquire knowledge, to solve problems, and to use acquired knowledge to create new, valued products. (p. 342)
interference
Failure to retain information in short-term memory that occurs when material learned earlier or later prevents its retention. (p. 222)
intergroup contact
A technique for reducing prejudice in which members of different groups meet and spend time together. (p. 537)
interpersonal therapy
A therapy approach in which therapists try to identify and change interpersonal problems contributing to clients’ psychological distress, especially by reducing clients’ social isolation. (p. 682)
interval schedule of reinforcement
In operant conditioning research, a timetable for reinforcement in which the reinforcer is delivered subsequent to the first response an organism makes after a specific period of time elapses. (p. 287)
intrinsic motivation
The desire to engage in activities because they are personally interesting, challenging, and enjoyable. (p. 483)
Iowa Gambling Task
A method for studying, via a card game with monetary payoffs, the influence of emotions on decision making. (p. 412)
IQ (intelligence quotient)
A measure of overall intelligence that takes into account a person’s age. (p. 343)
iris
The colorful eye structure that surrounds the pupil and responds to low and high light levels by dilating or constricting the pupil. (p. 175)
irrational beliefs
Demanding, dogmatic thoughts that distort reality illogically and cause people to experience negative emotions. (p. 669)
James–Lange theory of emotion
A theory of how the brain and body generate emotional experience in which physiological arousal, in response to an event, is said to precede and cause a subsequent emotional response. (p. 436)
just noticeable difference (JND)
The minimal variation in a physical stimulus such as light or sound that a person can detect. (p. 172)
kinesthetic system
The perceptual system that detects information about the location of body parts. (p. 160)
knowledge representation
The format in which knowledge in long-term memory is retained, and in which elements of that knowledge are interconnected. (p. 232)
language
A communication system in which sounds have meaning and rules govern the way in which linguistic units (e.g., words) can be combined. (p. 313)
latency stage
In Freud’s theory of psychological development, the developmental stage during which sexual desires are repressed into the unconscious until puberty. (p. 558)
lateral geniculate nucleus
Cells that receive visual signals and perform “computations” on them before transmitting the same signals to the visual cortex. (p. 180)
law of effect
A principle of learning which states that when an organism performs a behavior that leads to a satisfying outcome in a given situation, it will be more likely to perform that behavior when it again encounters the same situation. (p. 282)
learned helplessness
A severe reduction in motivation that occurs when animals learn that their own behavior cannot control unpleasant outcomes. (p. 273)
learning
Any relatively long-lasting change in behavioral abilities or emotional reactions that results from experience. (p. 260)
lens
An adjustable, transparent mechanism in the eye that focuses incoming light. (p. 175)
levels of analysis
Different ways of describing and explaining any given object or event. Psychological phenomena can be studied at three levels—person, mind, and brain. (p. 14)
levels of consciousness
Variations in the degree to which people are aware, and can become aware, of the contents of their minds. (p. 555)
lexical approach
A perspective on the task of identifying personality traits which presumes that all significant individual differences among people will be represented by naturally occurring words in everyday language. (p. 572)
life story
A narrative understanding of the major events and themes of one’s life. (p. 641)
lifespan developmental psychology
The field of study that explores human psychological development from the start of life through old age. (p. 642)
limbic system
A set of brain structures just above the brain stem, including the hypothalamus, hippocampus, and amygdala, that give mammals the capacity to experience emotional reactions. (p. 90)
lithium
A mood-stabilizing drug that centrally includes the physical element lithium; the classic drug of choice for treatment of bipolar disorder. (p. 687)
lobotomy
An outmoded surgical procedure for treating mental disorders in which a surgeon would damage brain tissue in the frontal cortex. (p. 678)
long-term memory
The mental system that stores knowledge for extended periods of time. (p. 227)
long-term potentiation
An enduring increase in the efficiency of communication between brain cells. (p. 249)
loudness
The subjective experience of the intensity, or strength, of an auditory experience. (p. 183)
LSD (lysergic acid diethylamide)
A synthetic chemical that affects the firing of neurons in the brain, thereby inducing widespread biological, and thus psychological, effects. (p. 398)
major depressive disorder
A disorder in which individuals experience some (but not necessarily all) of the following symptoms: depressed mood lasting at least two weeks, loss of interest in daily activities, changes in weight and sleep, fatigue, feelings of worthlessness and hopelessness, difficulty concentrating, and thoughts of suicide. (p. 681)
mania
A period of abnormally high energy, arousal, and often positive mood that can be accompanied by reckless behavior. (p. 686)
marijuana
A drug that produces a wide range of effects that commonly include both euphoria and a relaxed, tranquil state. (p. 401)
Maslow’s hierarchy of needs
A classification of human motives according to five basic needs, with lower-level needs requiring fulfillment before moving up to higher levels. (p. 458)
mean
The average score in a distribution (or set of numbers). (pp. 58, A-4)
means–ends analysis
A strategy for solving complex problems in which, at each step toward a solution, people aim to reduce the distance between their current state of progress and the final problem-solving goal they want to achieve. (p. 337)
measurement
Any procedure in which numbers are assigned to objects or events. (p. 52)
measures of central tendency
Statistics that describe the most representative score in a distribution, including mean, median, and mode. (p. A-4)
median
The middlemost score in a distribution. (p. A-4)
medical model of psychological disorders
Framework for thinking about the causes of, and treatments for, psychological disorders in a way that mimics thinking about physical illnesses. (p. 657)
meditation
Any practice in which people focus their attention for an extended period of time, as a method for increasing their ability to concentrate. (p. 391)
medulla
A structure in the brain stem that contributes to homeostasis by regulating rates of physiological activity and that serves as the communications pathway from the brain to the rest of the body. (p. 89)
memory
The capacity to retain knowledge. (p. 215)
mental accounting
A thinking process in which people divide their assets and expenditures into distinct cognitive categories, rather than thinking about their overall costs and net assets. (p. 336)
mental age
A measure of a child’s intelligence based on both the child’s test responses and the responses of other children who have taken the same test. The child’s mental age is equivalent to the average age of other children who perform as well as that child. (p. 344)
mental imagery
Thinking that involves pictures and spatial relationships rather than words, numbers, and logical rules. (p. 339)
mental module
A proposed subsystem of the mind and nervous system that performs a specific task in response to a specific type of environmental input. (p. 142)
mental rotation
The psychological process of turning an image in one’s mind, much as a person might turn a physical object in the world. (p. 340)
mental time travel
The ability to project yourself backward or forward in time in your mind. (p. 366)
mere exposure effect
Phenomenon in which people’s attitudes toward an object become more positive simply as a result of being exposed to the object repeatedly. (p. 530)
meta-analysis
A statistical technique for combining results from multiple studies in order to identify overall patterns in the studies as a whole. (p. 59)
midbrain
A structure of the brain stem that contributes to survival in several ways, such as by generating defensive reactions to threatening events. (p. 89)
mind–body problem
A conceptual problem that arises within dualistic theories (see dualism), namely, that there is no way to explain how a nonphysical mind can influence the physical body without violating laws of science. (p. 370)
mindset
A belief about the nature of psychological attributes, such as whether intelligence is fixed or can change. (p. 482)
mirror neurons
Neurons in the motor cortex that fire not only when an organism engages in an action, but also when it observes another organism engaging in that same action. (p. 301)
mirror self-recognition test
A method for evaluating an animal’s capacity to recognize itself in which researchers determine whether the animal looking at itself in a mirror behaves in a manner indicating its recognition of a mark made on its body. (p. 366)
mnemonics
Strategies for enhancing memory, in particular by organizing information in a manner that aids recall. (p. 246)
mode
The most frequently occurring score in a distribution. (p. A-4)
modeling
A form of learning in which knowledge and skills are acquired by observing others; also known as observational learning. (pp. 297, 585)
molecular genetic methods
Biological techniques for studying specific genes and variations in those genes; researchers relate this genetic information to variations in behavior. (p. 137)
monocular cues
Depth cues that are available even when we use only one eye. (p. 163)
monozygotic (MZ) twins
Siblings who, at conception, develop from a single fertilized cell that splits; identical twins. (p. 122)
mood
A prolonged, consistent feeling state, either positive or negative. (p. 410)
mood dimensions
Universal variations in feeling states; variations that can describe the mood of any and all people. (p. 431)
mood stabilizers
Drugs designed to reduce symptoms of bipolar disorder by affecting neurotransmitters in a way that calms and steadies a patient’s mood swings. (p. 687)
mood-as-information hypothesis
A proposal about the way in which feeling states influence thinking processes; in this hypothesis, moods inform thinking directly, as if they were sources of information. (p. 435)
moral development
Growth in reasoning about personal rights, responsibilities, and social obligations regarding the welfare of others. (p. 602)
moral judgments
Decisions that involve fundamental questions of right and wrong. (p. 420)
moral stage
According to Kohlberg, a period of development during which a person’s moral reasoning is consistently organized around a single way of thinking. (p. 647)
moratorium
According to Marcia, the identity status of people who contemplate many life options but are unable to commit to any one set of goals. (p. 638)
morpheme
The smallest unit of a language that itself conveys meaning; words contain one or more morphemes. (p. 315)
motivation
The psychological and biological processes that impel people, and other organisms, into action and sustain their efforts over time. (p. 458)
motivational orientations
Broad patterns of thoughts and feelings that can affect people’s behavior across a wide variety of tasks. (p. 482)
motor cortex
A region of the cerebral cortex that sends out signals controlling the body’s muscular movements. (p. 97)
motor neurons
Nerve cells that send out signals from the spinal cord to the body’s muscles, enabling the brain to control bodily movement. (p. 112)
multiple intelligences theory
A theory proposed by Gardner claiming that people possess a number of different mental abilities, each of which is a distinct form of intelligence. (p. 351)
myelin sheath
A fatty substance that surrounds axons and acts as an electrical insulator. (p. 108)
narcissistic personality disorder
A psychological disorder characterized by self-centeredness, concern with enhancing one’s self-image, and disregard for the thoughts and feelings of others. (p. 726)
narcolepsy
A sleep disorder in which people experience sudden, extreme feelings of sleepiness during the day, even if they’ve had adequate sleep; sometimes accompanied by “microsleeps.” (p. 385)
natural selection
The process whereby features of a population of organisms change, across generations, depending on the degree to which those features are adaptive (i.e., help organisms to survive and reproduce in a given environment). (p. 141)
nature
In psychology, a biological origin of psychological characteristics. Characteristics that come from nature are those that are inherited. (p. 23)
need for achievement
A desire to succeed on challenging activities requiring skilled, competent performance. (p. 467)
need to avoid failure
A desire to avoid situations in which lack of competence might lead to failure. (p. 468)
need for belonging
A social need that motivates people to spend time with others and to become part of social groups. (p. 469)
need for control
A desire to select one’s life activities and to be able to influence events. (p. 471)
need to enhance the self
A social need to grow as a person, to live a meaningful life, and to realize your true potential. (p. 471)
need for understanding
A social need to comprehend why events occur and to predict what the future might bring. (p. 470)
negative correlation
A correlation in which higher levels of one variable co-occur with lower levels of the other variable. (p. 44; see also p. A-12)
negative reinforcement
A stimulus whose removal following a behavior raises the future likelihood of that behavior. (p. 283)
negative symptoms (of schizophrenia)
The absence, among people with schizophrenia, of desirable psychological experiences common among most others (e.g., enjoying social events). (p. 706)
negatively skewed
Description of a distribution in which the majority of scores is high, but there is one or more extreme low score in the “tail.” (p. A-5)
neo-Freudian personality theories
Theories of personality inspired by Freud that attempted to overcome limitations in his work. (p. 562)
nervous system
The complete collection of neurons that transmits signals among the parts of the body. (p. 111)
neural pruning
Elimination of connections among neurons that occurs when the connections are not needed for an organism’s functioning. (p. 152)
neurons
Brain cells, also called nerve cells, distinguished by their unique shape and ability to communicate with one another. (p. 106)
neurotransmitters
Chemical substances that travel across synapses between neurons; the primary way that neurons communicate. (p. 108)
nicotine
A stimulant found in tobacco products that increases alertness while enhancing feelings of pleasure and emotional well-being. (p. 400)
nociceptors
Specialized pain receptors that are activated by harmful stimuli such as a cut or burn. (p. 202)
non-REM sleep
Sleep stage in which brain activity differs from that of waking states, and breathing rate, heart rate, blood pressure, and body temperature are relatively low. (p. 378)
normal distribution
A distribution that is symmetrical and unimodal; the mean, mode, and median are equal. (p. A-5)
null hypothesis
A hypothesis stating that any relationship observed between variables will be due to chance. (p. A-17)
null hypothesis significance testing
A statistical procedure that calculates the probability that a research result could have occurred by chance alone. (p. A-20)
nurture
The development of abilities through experiences in the world. Abilities that come from nurture are those that are learned rather than inherited. (p. 23)
obedience
Adherence to the instructions and commands of an authority figure. (p. 514)
object permanence
The understanding that objects continue to exist even when they can no longer be seen or otherwise perceived. (p. 605)
observational learning
A form of learning in which knowledge and skills are acquired by observing others; also known as modeling. (p. 297)
observational study
A type of research in which researchers observe people’s behavior from a distance without interacting with them. (p. 62)
observer report
A research method in which researchers learn about various characteristics of a given individual by obtaining reports from other people who know that person. (p. 64)
obsessive-compulsive disorder (OCD)
A mental disorder involving both recurring, intrusive thoughts about potential danger or harm (obsessions) and repetitive actions (compulsions) taken to prevent the imagined dangers and harms. (p. 695)
obsessive-compulsive personality disorder (OCPD)
A psychological disorder characterized by perfectionism, a seeking of order and control, rigid adherence to rules for behavior, and attention to small details. (p. 727)
occipital lobe
The region of the cerebral cortex heavily involved in the processing of visual information and mental imagery; commonly called the visual cortex. (p. 95)
occlusion
A monocular depth cue in which one object in the field of vision partly blocks another from view. (p. 164)
odorant
Anything that smells; odorants include a variety of substances such as foods, pheromones, and chemical signals of cell damage and disease. (p. 190)
olfactory bulbs
Collections of cells near the front of the brain that receive signals from olfactory receptor cells and begin the process of identifying odors. (p. 192)
olfactory cortex
A neural system that completes the biological processing needed to recognize smells. (p. 192)
olfactory system
The perceptual system that detects airborne chemical substances and provides the sense of smell. (p. 160)
operant conditioning
A form of learning in which the future likelihood of performing a type of behavior is modified by consequences that follow performance of the behavior. (p. 279)
operation
In Piagetian theory, a reversible action that modifies an object or set of objects, either physically or conceptually. (p. 604)
operational definition
The specification of a procedure that can be used to measure a variable. (p. 52)
opioids
Chemical substances whose primary psychoactive effect is the reduction of pain; can also induce feelings of euphoria and ecstasy. (p. 399)
optic chiasm
The location in the brain where visual signals carried by the optic nerves cross, sending information from the left eye to the right side of the brain, and vice versa. (p. 179)
optic nerve
The biological pathway along which information leaves the eye and moves toward the brain, formed by the long fibers of ganglion cells. (p. 179)
optical flow
The continuous change in visual images that occurs when organisms move through the environment. (p. 170)
optimization
In the selection, optimization, and compensation (SOC) model of successful aging, the process of devising plans to achieve goals you set. (p. 643)
oral stage
In Freud’s theory of psychological development, the developmental stage (ages 0 to 18 months) during which children seek gratification through the mouth. (p. 558)
ovaries
The reproductive cells in women that produce ova (eggs). (p. 115)
oxytocin
Hormone that activates muscles needed for childbirth and stimulates the release of breast milk; in the brain, it may stimulate feelings of trust. (p. 473)
pancreas
The organ that releases hormones including insulin, which regulates the level of sugar in the bloodstream. (p. 115)
panic attack
An episode of extreme fear, including high levels of physical arousal, that occurs suddenly and without apparent cause. (p. 690)
panic disorder
A psychological disorder in which people experience the sudden bouts of intense terror and extreme physiological arousal known as panic attacks. (p. 690)
parallel distributed processing (PDP)
A conceptual model of knowledge representation in which long-term memory consists of simple processing units that turn on and off; concepts are represented by patterns of activation in large numbers of units. (p. 235)
parasympathetic nervous system
A component of the autonomic nervous system that maintains normal functioning of the body when one is not under threat or stress by activating digestion and waste elimination and restoring baseline heart rate and blood pressure. (p. 113)
parietal lobes
The region of the cerebral cortex that processes somatosensory information (i.e., relating the body to the environment). (p. 95)
perception
The biological process occurring when systems in the brain process sensory signals and produce awareness of sensory inputs. (p. 161)
perceptual systems
Interconnected parts of the body that deliver sensory and perceptual information; humans have six perceptual systems. (p. 160)
peripheral nervous system
That part of the nervous system found in the periphery of the body, outside of the central nervous system; it consists of the somatic nervous system and the autonomic nervous system. (p. 112)
personal agency
People’s capacity to influence their motivation, behavior, and life outcomes by setting goals and developing skills. (pp. 475, 581)
personality
The relatively consistent, observable patterns of feeling, thinking, and behaving that distinguish people from one another, and the inner psychological systems that explain these patterns. (p. 551)
personality assessment
A structured procedure for learning about an individual’s distinctive psychological qualities. (p. 553)
personality disorders
Psychological disorders that feature chronic styles of thinking, behavior, and emotion that severely lower the quality of people’s relationships, creating conflict with others. (p. 722)
personality processes
Individuals’ distinctive patterns of change in psychological experience and behavior that occur from one moment to the next. (p. 552)
personality structures
Those elements of personality that remain consistent over significant periods of time. (p. 552)
personality theory
A comprehensive scientific model of human nature and individual differences. (p. 552)
phallic stage
In Freud’s theory of psychological development, the developmental stage (3½ to 6 years) during which the source of gratification is the genitals. (p. 558)
phantom limb syndrome
The subjective conscious feeling that an amputated limb is still attached to one’s body. (p. 363)
pheromones
Chemical signals produced and secreted by one organism and detected by another organism of the same species, triggering a distinctive reaction. (p. 190)
phi phenomenon
An illusory perception of visual motion that occurs when stationary objects flash in an alternating sequence and are perceived as a single object moving back and forth. (p. 169)
phobias
Strong, persistent fears caused by situations that pose little or no actual threat. (p. 693)
photoreceptors
Receptor cells in the eye that are sensitive to stimulation by light. (p. 162)
pineal gland
An endocrine gland that produces a hormone called melatonin that influences patterns of sleeping and wakefulness. (p. 114)
pitch
The sound experience that we usually describe with the words “low” or “high” (such as a musical note or voice). (p. 184)
pituitary gland
The “master gland” of the endocrine system; it releases hormones that influence biological activity in several other glands, including those that regulate stress response, reproduction, and metabolic rate. (p. 115)
placebo effect
In drug therapies, any medical benefit not caused by biologically active properties of the drug, but by the patient’s expectation that the drug will help him. (p. 677)
plasticity
The brain’s capacity to change physically as a result of experience. (p. 84)
p-level
The probability that results are due to chance, under the null hypothesis. (p. A-20)
pons
A structure of the brain stem that carries out biological functions, including the control of breathing rate and generation of REM sleep. (p. 89)
population
The overall, large group of people of interest to a researcher conducting a study. (p. 42)
positive correlation
A correlation (statistical relation between two variables) in which higher levels of one variable co-occur with higher levels of the other variable. (p. 44; see also p. A-11)
positive psychology
An intellectual movement that emphasizes positive individual traits such as love, courage, and forgiveness rather than human frailties. (p. 29)
positive reinforcement
A stimulus whose occurrence following a behavior raises the future likelihood of that behavior. (p. 283)
positive symptoms (of schizophrenia)
Undesirable mental events experienced by people with schizophrenia but rarely by others. (p. 705)
positively skewed
Description of a distribution in which the majority of scores is low, but there is one or more extreme high score in the “tail.” (p. A-5)
positivity effect
A phenomenon in which older adults pay more attention to positive information when recalling and contemplating personal experiences. (p. 646)
postpartum depression
A depressive disorder in which some women experience symptoms akin to major depression beginning within weeks of childbirth. (p. 687)
posttraumatic stress disorder (PTSD)
A mental disorder characterized by flashbacks to previously encountered highly stressful experiences, such as military combat or sexual assault. (p. 696)
preconscious
In Freud’s analysis of levels of consciousness, regions of mind containing ideas you can easily bring to awareness. (p. 555)
predictor variable
In a correlation between two variables, the value that is used to predict the value of the other (criterion) variable. (p. A-12)
prefrontal cortex
The area of the brain immediately behind the forehead; a complex area that contributes to the ability to concentrate on facts, focus attention, manipulate information, and align behavior with social rules. (p. 97)
prejudice
A negative attitude toward individuals based on their group membership, involving disparaging thoughts and feelings about individuals in a group. (p. 534)
prenatal environment
The biological environment experienced before a person is born. (p. 149)
preoperational stage
In Piaget’s theory of child development, the stage (ages 2 to 7) in which children can use mental symbols, such as words and numbers, to think, yet still cannot perform logical operations. (p. 605)
preparedness
The ease with which associations between a stimulus and a response can be learned; as a result of a species’ experiences over the course of evolution, some stimulus–response connections are “prepared,” that is, are easy to learn. (p. 275)
pressure
In the study of auditory perception, a cue to the location of a sound source that is based on the difference in pressure on left and right ears produced by a sound wave coming from one side. (p. 186)
prevention focus
A mental approach to activities in which the mind is focused on responsibilities and obligations. (p. 485)
priming
The presentation of information (a “prime”) that activates a concept stored in memory. (p. 234)
proactive interference
A short-term memory impairment that occurs when material learned earlier impairs memory for material learned later. (p. 222)
problem solving
A thinking process in which people try to reach a solution by working through a series of steps. (p. 336)
problem space
The full set of steps it is possible to take when solving a problem. (p. 337)
procedural memory
Memory for how to perform behaviors. (p. 229)
projective test
Personality assessment tool in which items are ambiguous and psychologists are interested in the way test takers interpret the ambiguity, “projecting” elements of their own personality onto the test. (p. 561)
promotion focus
A mental approach to activities in which the mind is focused on accomplishments that one personally hopes to attain. (p. 484)
prosocial behavior
Actions that directly benefit others, such as comforting those in distress. (p. 638)
prototype
The most typical, central member of a category. (p. 311)
prototype structure
A category structure in which category membership is defined according to the resemblance of items to a central, most typical member (the prototype). (p. 311)
proximal causes
In an evolutionary analysis, events and mechanisms in the present environment that determine an organism’s responses. (p. 141)
proximal goal
A goal that specifies what should be done in the near (“proximal”) future. (p. 476)
psychiatrists
Physicians trained in the diagnosis and treatment of mental disorders, with particular emphasis on the biological basis of disorders and the use of drugs to combat them. (p. 656)
psychoactive drug
Any chemical substance that affects the nervous system in a manner that alters conscious experience. (p. 397)
psychoactive substances
Chemical substances small enough to cross the blood–brain barrier that affect psychological processes of perception, thinking, or emotion. (p. 677)
psychoanalysis
The psychotherapy strategy originally developed by Sigmund Freud; a type of insight therapy. (p. 665)
psychoanalytic theory
Freud’s theory of personality, also called psychodynamic theory. (p. 554)
psychodynamic processes
In Freud’s theory, changes in mental energy that occur as energy flows from one personality structure to another, or is directed to desired objects. (p. 557)
psychological disorders
Prolonged experiences of psychological distress or poor psychological functioning that interfere with a person’s everyday life; mental disorders. (p. 656)
psychological therapies (psychotherapies)
Interactions between a therapist and client(s) in which the therapist speaks with the client, with a goal of improving emotional state, thinking, and behavioral skills. (p. 665)
psychology
The scientific study of persons, the mind, and the brain. (p. 4)
psychopathy
A personality style defined by hostility toward others, lack of guilt, and a tendency toward dishonesty and manipulation of others. (p. 724)
psychophysics
A branch of psychology that studies relations between physical stimuli and psychological reactions. (p. 172)
psychophysiology
A field of study that provides scientific information about the relation between physiological reactions and psychological experiences. (p. 68)
psychosexual stage
In Freud’s theory of psychological development, a period during which the child focuses on obtaining sensual gratification through a particular part of the body. (p. 558)
psychotherapists
Professionals who provide psychological therapies. (p. 665)
psychotic disorders
Psychological disorders in which thoughts and actions are disorganized and thinking loses touch with reality; people see and worry about things that do not exist. (p. 705)
puberty
The time when a child reaches sexual maturity and is biologically capable of reproduction. (p. 635)
punishment
In operant conditioning, a stimulus that lowers the future likelihood of a given behavior. (p. 284)
pupil
The opening in the eye through which light passes. (p. 175)
Q-sort
An assessment procedure in which people categorize words and phrases according to how well or poorly the descriptions fit them. (p. 568)
qualitative data
Sources of scientific information that are not converted into numbers, but reported in words. (p. 51)
qualitative research methods
Any of a wide range of methods in which researchers observe, record, and summarize behavior using words rather than numbers. (p. 51)
quantitative data
Numerical data, that is, data in which scientific observations are recorded using numbers. (p. 51)
quantitative research methods
Scientific methods in which participants’ responses are described in terms of numbers. (p. 51)
questionnaire
A set of questions or statements to which participants respond by choosing response options that best characterize their own thoughts. (p. 64)
random assignment
A process in which participants are allocated to conditions of an experiment on an entirely chance basis. (p. 49)
random sample
A sample in which each individual’s inclusion, or not, is determined by a chance process. (p. 42)
range
A simple measure of the variability of a distribution; the difference between the highest and lowest scores. (p. A-7)
ratio schedule of reinforcement
In operant conditioning research, a timetable for reinforcement in which a reinforcer is administered only after an organism performs a certain number of responses. (p. 287)
reasoning
The process of drawing conclusions that are based on facts, beliefs, and experiences, combining them to reach conclusions that go beyond the information originally perceived. (p. 328)
receptor cells
Nervous system cells that are sensitive to specific types of physical stimulation from the environment and send signals to the brain when stimulated. (p. 162)
receptors
Sites on the dendrites of receiving neurons to which neurotransmitters can attach; chemically, molecules to which specific types of neurotransmitters can bind. (p. 109)
reflection
In psychotherapy, an active-listening technique in which the therapist recurringly summarizes statements made by the client, “reflecting” the content back to the client. (p. 671)
reflexes
Automatic, involuntary responses to external stimulation. (p. 112)
regulatory fit
The match between a motivational orientation and a behavioral strategy. (p. 485)
rehearsal
The strategy of repeating information to retain it in short-term memory. (p. 223)
reinforcer
In operant conditioning, any stimulus that occurs after a response and raises the future probability of that response. (p. 283)
reliability
An attribute of a measure; specifically, a measure possesses “reliability” if it produces results that are consistent from one measurement occasion to another. (p. 54)
REM (rapid eye movement) sleep
A sleep stage during which there is rapid eye movement, frequent dreams, and brain activity resembling that of waking periods. (p. 378)
representative sample
A sample in which the qualities of the individuals included match those of the overall population. (p. 42)
representativeness heuristic
A psychological process in which people judge whether a person or thing belongs to a given category by evaluating the degree to which the person or object resembles the category. (p. 332)
repression
A defense mechanism in which traumatic memories are kept in the unconscious, thereby blocked from awareness. (p. 559)
research design
Plans for the execution of scientific research projects. (p. 38)
resilience
The capacity to retain or recover psychological functioning after negative experiences. (p. 624)
reticular formation
A network of cells in the brain stem that influences bodily arousal. (p. 89)
retina
The rear wall of the eye containing nerve cells that respond to light and send signals to the brain. (p. 175)
retrieval
The access of information that has been stored in long-term memory. (p. 230)
retroactive interference
A short-term memory impairment that occurs when material learned later impairs memory for material learned earlier. (p. 222)
rods
Photoreceptors that enable vision in low illumination. (p. 177)
role
A set of behaviors that is expected of a person in a given situation. (p. 516)
Rorschach inkblot test
A projective test in which the test items are symmetrical blobs of ink that test takers are asked to interpret. (p. 561)
saccades
Rapid movements of the eyes from one position to another. (p. 177)
sample
The select subgroup of people contacted by a researcher, who uses information from the sample to draw conclusions about the population as a whole. (p. 42)
sampling error
Chance differences between sample statistics and population statistics (called parameters); for example, the difference between the mean of a population and the mean of a sample drawn from it. (p. A-17)
Sapir–Whorf hypothesis
A conception of the relation between language and thought which claims that language shapes thinking; this hypothesis implies that people who speak different languages think differently about the world around them. (p. 324)
satiety
A feeling of having eaten enough food, or being “full.” (p. 460)
savant syndrome
A syndrome characterized by mental impairment in most areas of life but exceptional performance in one domain. (p. 353)
scapegoating
Blaming members of another group when frustrated with one’s own circumstances. (p. 537)
scatterplot
A graph that displays the relation between two variables. Data points representing the measurements of the two variables “scatter” about the visual display. (p. 44; see also p. A-11)
schedule of reinforcement
In operant conditioning research, a timetable that indicates when reinforcements occur, in relation to the occurrence of behavior. (p. 287)
schema
A mental structure that makes organized, meaningful action possible. (p. 603)
schizophrenia
Psychological disorder in which people exhibit multiple psychotic symptoms. (p. 705)
schizotypal personality disorder
A psychological disorder characterized by (1) odd beliefs, eccentricity in manner or dress, and suspiciousness; and (2) few close friends, that is, social isolation resulting from these beliefs and behaviors. (p. 727)
scientific methods
A broad array of procedures through which scientists obtain information about the world. Scientific methods involve three key steps: collect evidence, record observations systematically, and record how observations were made. (p. 9)
scientific questions
Questions that can be answered by gathering evidence through scientific methods. (p. 10)
scientific theory
In science, a systematic, data-based explanation for a phenomenon or set of phenomena. (p. 70)
seasonal affective disorder
A depressive disorder in which individuals experience depressed mood during late summer and winter, periods when there is less sunlight. (p. 687)
secure attachment
The attachment style in which a child has a positive relationship with his or her mother, with a sense of security that enables the child to explore the world, confident of the mother’s comfort. (p. 623)
selection
In the selection, optimization, and compensation (SOC) model of successful aging, the process of setting personal goals for a given period of your life. (p. 643)
selection, optimization, and compensation (SOC) model
A model of successful aging that identifies three psychological processes that promote positive personal development: selection, optimization, and compensation. (p. 643)
selective attention
The capacity to choose the flow of information that enters conscious awareness. (p. 204)
selective serotonin reuptake inhibitors (SSRIs)
Pharmaceuticals designed to alleviate depression by increasing serotonin activity through interference with the biochemical process known as reabsorption or reuptake. (p. 675)
self
In humanistic theories, such as that of Rogers, an organized set of self-perceptions of our personal qualities; people’s conceptions of who they are. (p. 566)
self-actualization
A motivation to realize one’s inner potential. (pp. 459, 567)
self-consciousness
The process of thinking about oneself, that is, thinking about one’s own experiences and how one appears to others. (p. 366)
self-control
The ability to act in a manner consistent with long-term goals and values, even when one feels an impulse to act differently. (p. 633)
self-efficacy beliefs
Judgments about one’s own capabilities for performance. (p. 583)
self-esteem
A person’s overall sense of self-worth. (pp. 570, 633)
self-referent cognitions
Thoughts people have about themselves as they interact with the world and reflect on their experiences. (p. 582)
self-regulation
People’s efforts to control their own behavior and emotions. (p. 587)
self-report
Research techniques in which researchers ask participants to provide information about themselves. (p. 64)
self-representations
Beliefs about the characteristics of oneself and the ways in which one differs from other people. (p. 632)
semantic memory
Memory for factual information. (p. 228)
semantic network model
A conceptual model of knowledge representation in which long-term memory consists of a large set of individual concepts connected to one another. (p. 232)
sensation
The biological process occurring when cells at the periphery of the body detect physical stimuli. (p. 161)
sensorimotor stage
In Piaget’s theory of child development, the stage (birth to 2 years) in which a child interacts with the world through his or her sensory and motor systems. (p. 605)
sensory cortex
A region of the parietal cortex that receives sensory information from all parts of the body. (p. 96)
sensory memory
Memory that is based on the workings of sensory systems. (p. 217)
sensory neurons
Nerve cells that respond to external stimuli and send messages about the environment to the spinal cord. (p. 111)
serial position effect
The tendency to display superior recall for items positioned at the beginning or end of a list rather than in the middle. (p. 223)
set-point theories
Theoretical explanations of hunger and eating which propose that homeostatic processes control food consumption, with people being motivated to eat (or not) when their energy supplies fall below (or above) their set point. (p. 461)
sexual orientation
A person’s primary form of sexual and romantic attachment, whether to the opposite sex (heterosexual), the same sex (homosexual), or both (bisexual). (p. 147)
shading
A monocular depth cue based on the presence within a visual image of a relatively dark area that appears to have been created by blocking a source of light. (p. 164)
shaping
In operant conditioning, the learning of complex behavior through a step-by-step process in which behaviors that successively approximate a desired, final behavior are reinforced. (p. 291)
short-term memory
A memory system that enables people to keep a limited amount of information actively in mind for brief periods of time. (p. 219)
sign language
A language in which bodily movements, especially of the hands and fingers, are used to convey information. (p. 323)
single-nucleotide polymorphisms (SNPs)
Locations along the genome at which one molecule (i.e., one nucleotide) differs from one individual to another. (p. 717)
skewed distribution
An asymmetrical distribution in which the mean is no longer in the middle because it is “pulled” by extreme scores. (p. A-5)
skills
Abilities that develop through experience, including interpersonal skills. (p. 583)
skin conductance response (SCR)
A measure of electrical resistance at the skin that uses the activity of sweat glands to provide a physiological measure of anxiety. (p. 68)
Skinner box
The primary laboratory apparatus in the study of operant conditioning; it includes a device for animals to act upon (e.g., a lever to press) and a mechanism for delivering reinforcers. (p. 286)
sleep apnea
A disorder in which people suffer from brief pauses in breathing while they are asleep, causing them to wake up. (p. 386)
sleep deprivation
Going without adequate sleep, which not only makes you tired but also impairs normal conscious experiences. (p. 384)
sleep disorder
Any medical condition that disrupts normal patterns of sleep. (p. 385)
sleep laboratory
A scientific facility for studying sleep; research participants spend nights sleeping while their biological rhythms and brain activity are monitored. (p. 382)
sleep stages
The sequence of changes in REM and non-REM sleep that everyone experiences in the same order. (p. 380)
social anxiety disorder
A disorder characterized by extreme levels of anxiety and self-consciousness specifically in situations involving other people. (p. 691)
social behavior
Behavior that occurs in interaction with other people. (p. 506)
social cognition
People’s beliefs, opinions, and feelings about the individuals and groups with whom they interact socially. (p. 524)
social development
Growth in ability to function effectively in the social world, especially by controlling emotions, maintaining relationships, and establishing a personal identity. (p. 602)
social facilitation
A phenomenon in which the mere presence of other people improves people’s performance on tasks on which they are skilled. (p. 489)
social loafing
A reduction in individual motivation on group tasks in which some people expect that the group is likely to succeed without their efforts. (p. 489)
social needs
Desires that motivate people to interact with others and to achieve a meaningful role in society. (p. 469)
social neuroscience
A field of study that explores biological systems in the brain that underlie social cognition and behavior. (p. 542)
social norm
A socially shared belief about the type of behavior that is acceptable in any given setting. (p. 508)
social psychology
Branch of psychology that studies people’s thoughts, feelings, and actions as they contemplate, interact with, and are influenced by others in society. (p. 506)
social support
Loving care and personal assistance from friends and family, particularly as provided during times of stress. (p. 451)
social-cognitive theory
A theoretical approach to personality in which the core of personality consists of personal knowledge, beliefs, and skills acquired through social interaction. (p. 580)
socioemotional selectivity theory
A lifespan developmental theory of motivational processes that explains how perceptions of the amount of time remaining in life affect motivation. (p. 644)
somatic nervous system
Functionally, the part of the peripheral nervous system that provides the brain-to-periphery communications that allow(s) you to control your bodily movement. (p. 112)
sound waves
Variations in pressure that reach the ears and are converted by the auditory system into signals. (p. 182)
spatial memory
The ability to recall the layout of one’s physical environment. (p. 250)
specific phobias
Fears directed toward particular objects or situations, such as fear of flying, heights, spiders, or closed-in spaces. (p. 693)
spinal cord
A bundle of neurons and glial cells that extends from the brain stem down to the bottom of the spine; it participates in two-way communications between the brain and the body. (p. 111)
spinal nerves
Those parts of the peripheral nervous system that extend from the spinal cord to the body’s neck, torso, and limbs. (p. 112)
split brain
A surgical procedure in which the corpus callosum is cut. The resulting disruption of information transmission between cerebral hemispheres alters conscious experience. (p. 101)
spontaneous recovery
The reappearance of an extinguished conditioned response after a period of delay following extinction. (p. 269)
standard deviation
A statistic that describes the degree to which numbers vary, or deviate, from the mean. (p. 58; see also p. A-7)
standard error
A statistic that quantifies sampling error or chance differences between the sample and the population. (p. A-18)
statistical language learning
A theory of language acquisition proposing that people acquire language by learning patterns of sounds and words that they hear frequently, that is, that are statistically common. (p. 318)
statistically significant
An experimental result is said to be statistically significant if observed outcomes vary from what would be expected by chance. (p. 58; see also p. A-20)
statistics
Mathematical procedures for summarizing sets of numbers. (p. 58; see also p. A-1)
stereopsis
The perception of three-dimensional space produced by the fact that images reaching your two eyes vary slightly because your eyes are a few inches apart; a binocular depth cue. (p. 166)
stereotype
A simplified set of beliefs about the characteristics of members of a group. (p. 533)
stereotype threat
A negative emotional reaction that occurs when people recognize the possibility of their confirming a negative stereotype about their group. (p. 534)
stimulants
Psychoactive drugs that increase nervous system activity and thus enhance alertness and energy. (p. 400)
strange situation paradigm
A behavioral measure of attachment style in which researchers record a child’s responses to a sequence of events in which the mother and child interact, are separated, and reunite. (p. 624)
stress response
A coordinated series of physiological changes that prepare you for “fight or flight”; that is, to confront the stressor, or flee. (p. 444)
structuralism
A school of thought focusing on the mind’s basic components, or structures, and how they come together to create complex mental experiences. (p. 27)
subjective stress
The psychological impact of a potentially stressful event from the perspective of the individual experiencing it. (p. 442)
subjective value
The degree of personal worth that an individual places on an outcome. (p. 334)
sublimation
A defense mechanism in which an instinct toward sex or aggression is redirected to the service of a socially acceptable goal. (p. 559)
superego
In Freud’s psychoanalytic theory, the personality structure that represents society’s moral and ethical rules. (p. 555)
supertasters
People who have greater sensitivity to tastes than others. (p. 195)
suppression
Any conscious, intentional effort to prevent oneself from showing any visible sign of emotional arousal (or other such psychological states). (p. 427)
survey method
A research design in which researchers obtain descriptive information about a large group of people by studying a select subgroup of them. (p. 40)
sympathetic nervous system
A component of the autonomic nervous system that prepares organisms or action by activating biological systems required for “fight or flight” responses. (p. 112)
synapse
The small gap that separates any two neurons; chemical signals between neurons must bridge this microscopic gap. (p. 108)
synaptic vesicles
Small sacs that store and transport neurotransmitters within neurons and release neurotransmitters into synapses. (p. 108)
syntax
The set of rules determining whether a series of phrases form a sentence that is grammatically correct. (p. 315)
systematic desensitization
An exposure therapy that reduces fear by exposing clients to feared objects in a slow, gradual manner. (p. 668)
systematic information processing
Careful, detailed, step-by-step thinking. (p. 528)
tardive dyskinesia
Repetitive, uncontrollable muscular movements, typically of the face, such as odd grimacing and lip smacking; a side effect of antipsychotic medication. (p. 719)
taste buds
Bundles of taste receptors, found primarily on the tongue but also on the roof of the mouth and throat. (p. 196)
taste receptors
Cells that are stimulated by chemical substances in food, whose activation begins the process of transmitting gustatory information to the brain. (p. 196)
temperament
Biologically based emotional and behavioral tendencies on which individuals differ. (p. 618)
temperament dimension
A biologically based psychological quality possessed by all children to a greater or lesser degree, such as emotionality, activity, or sociability. (p. 619)
temporal lobe
The region of the cerebral cortex crucial to psychological functions, including hearing and memory. (p. 96)
tend-and-befriend
A coping strategy identified particularly in women in which the response to threat involves taking action to help others (tending) while maintaining a close support network (befriending). (p. 451)
terror management theory
A theory proposing that death is so terrifying that thinking about it increases feelings of identification with institutions (e.g., religions, nations) that will survive one’s death. (p. 558)
testes
The reproductive cells in men that produce sperm. (p. 115)
testosterone
Hormone that plays a role in motivating sexual desire in both men and women. (p. 466)
texture
A monocular depth cue based on markings on the surface of objects in a visual scene. (p. 164)
thalamus
A structure near the center of the brain that serves as a “relay station” for rapid connections among brain regions. (p. 103)
theory of mind
An intuitive understanding that other people have feelings and thoughts. (p. 611)
think-aloud protocol analysis
A research method in which participants verbalize their thoughts while solving a problem, which enables experimenters to record and analyze the problem-solving strategies used. (p. 338)
three-stage memory model
A conceptual depiction of the memory system in which information is said to be stored in any of three storage systems: sensory memory, short-term memory, or long-term memory. (p. 217)
thymus
An endocrine gland that produces hormones influencing the development and functioning of the immune system. (p. 115)
thyroid gland
An endocrine gland that releases hormones regulating the body’s metabolic rate. (p. 115)
timbre
The distinctive “signature” of a sound, based on variations in the complexity of sound waves. (p. 185)
timing
In the study of auditory perception, a cue to the location of a sound source that is based on the difference in time it takes a sound coming from your side to reach each ear. (p. 186)
token economy
A behavior therapy technique in which therapists reward desirable behavior with tokens that serve as reinforcers, making the behavior more likely to reoccur. (p. 668)
trait
In personality psychology, a person’s typical style of behavior and emotion. (p. 571)
trait theories
Theoretical approaches that try to identify, describe, and measure people’s personality traits. (p. 571)
transduction
A biological process in which physical stimuli activate cells in the nervous system, which then send nerve impulses to the brain, where processing gives rise to perceptual and sensory experience. (p. 162)
transference
A psychoanalytic process in which a patient unintentionally responds emotionally to a therapist as if the therapist were a significant figure from the patient’s past, such as a parent. (p. 666)
transformational grammar
The set of rules governing how components of a sentence can be shifted to create other sentences that are grammatically correct. (p. 316)
triarchic theory of intelligence
A theory of intelligence proposed by Sternberg, which says that intelligent behavior requires three distinct mental components: knowledge acquisition, executive planning, and performance. (p. 354)
triune brain
Conceptual model of brain structure distinguishing among three main parts of the human brain that evolved at different points and perform distinct functions. (p. 87)
t-statistic
A statistic used in the t-test that is the ratio of the hypothesized difference against chance differences. (p. A-19)
t-test
The statistical procedure for evaluating whether differences observed between two sample means represent true population mean differences or chance. (p. A-19)
twin method
A procedure for determining the degree to which genes account for individual differences by comparing degrees of similarity among MZ and DZ twins. (p. 128)
two-point procedure
A method to measure haptic system acuity that assesses the smallest distance at the skin at which people can perceive two separate stimuli rather than one. (p. 198)
type I error
In statistics, rejecting the null hypothesis when it is, in fact, true. (p. A-20)
typical antipsychotics
One of two major types of antipsychotic drugs, specifically, the first such drugs developed, in the 1950s. (p. 719)
umami
A taste sensation that is “savory,” triggered by high protein levels in food. (p. 194)
unconditional positive regard
A display of respect and acceptance toward others that is consistent and not dependent on their meeting behavioral requirements. (pp. 567, 671)
unconditioned response (UR)
A reaction to an unconditioned stimulus that occurs automatically, prior to any learning. (p. 262)
unconditioned stimulus (US)
A stimulus that elicits a reaction in an organism prior to any learning. (p. 262)
unconscious
In Freud’s analysis of levels of consciousness, regions of mind containing ideas you are not aware of and generally cannot become aware of even if you wanted to. (p. 555)
unimodal
Term describing a distribution having only one mode. (p. A-5)
uninhibited temperament
A tendency to experience little fear and to act in a spontaneous and sociable manner. (p. 620)
universal grammar
A set of linguistic rules that, according to Chomsky, are possessed by all humans and that enable people to understand and produce sentences. (p. 317)
validity
An attribute of a measure; specifically, a measure possesses “validity” if it measures what it is supposed to measure. (p. 54)
variability
The degree to which the scores in a distribution spread out above and below the mean. (p. A-7)
variable
Any property that fluctuates, such as from person to person or from time to time. (p. 43)
variable schedule of reinforcement
In operant conditioning research, a timetable for reinforcement that is inconsistent across trials; the delivery of reinforcers changes unpredictably. (p. 287)
ventricles
Spaces in the brain filled with a fluid that supports brain functioning but without neurons; enlarged in people with schizophrenia. (p. 713)
visual cortex
A region in the rear of the brain devoted to processing visual information. (p. 180)
visual fixations
Periods when a person’s gaze is held in one location, when most visual information is picked up. (p. 177)
visual system
The perceptual system detecting environmental information that reaches the body in the form of light. (p. 160)
Wechsler Adult Intelligence Scale (WAIS)
A popular test of intelligence that assesses verbal comprehension, perceptual reasoning, working memory, and mental processing speed. (p. 344)
Wernicke’s area
A region in the temporal lobe of the left hemisphere of the brain needed to understand language and to produce meaningful sentences. (p. 321)
wish-fulfillment theory
Freud’s proposal that dreams help us stay asleep by depicting the fulfillment of unconscious wishes, thereby releasing pent-up mental energy. (p. 388)
working memory
A set of interrelated systems that both store and manipulate information; its three components are the phonological loop, visuospatial sketchpad, and central executive. (p. 225)
x-axis
In any graph, the horizontal axis. (p. A-3)
y-axis
In any graph, the vertical axis. (p. A-3)
zone of proximal development
In Vygotsky’s theory of cognitive development, the region between a child’s current level of independent cognitive development and the level he or she can achieve only through interaction with others. (p. 612)
z-score
A statistic that tells you how far a given score is from the mean of a distribution, in standard units. (p. A-10)