McGraw-Hill OnlineMcGraw-Hill Higher EducationLearning Center
Student Center | Instructor Center | Information Center | Home
Career Opportunities
Glossary
Internet Guide
Study Skills Primer
Statistics Primer
Grade Summit
PowerWeb
Feedback
Help Center


Psychology 5/e Book Cover
Psychology, 5/e
Lester M. Sdorow, Arcadia University
Cheryl A. Rickabaugh, University of Redlands


Glossary


absolute threshold  The minimum amount of stimulation that an individual can detect through a given sense.
accommodation  

1. The cognitive process that revises existing schemas to incorporate new information.

2. The process by which the lens of the eye increases its curvature to focus light from close objects or decreases its curvature to focus light from more distant objects.


achievement motive  The desire for mastery, excellence, and accomplishment.
achievement test  A test that measures knowledge of a particular subject.
acronym  A mnemonic device that involves forming a term from the first letters of a series of words that are to be recalled.
action potential  A series of changes in the electrical charge across the axonal membrane that occurs after the axon has reached its firing threshold.
activation-synthesis theory  The theory that dreams are the by-products of the mind's attempt to make sense of the spontaneous changes in physiological activity generated by the brain stem during REM sleep.
acupuncture  A pain-relieving technique that relies on the insertion of fine needles into various sites on the body.
adaptation-level theory  The theory that happiness depends on comparing one's present circumstances with one's past circumstances.
adolescence  The transition period lasting from the onset of puberty to the beginning of adulthood.
adrenal glands  Endocrine glands that secrete hormones that regulate the excretion of minerals and the body's response to stress.
adulthood  The period beginning when the individual assumes responsibility for her or his own life.
age regression  A hypnotic state in which the individual apparently behaves as she or he did as a child.
aggression  Verbal or physical behavior aimed at harming another person.
agoraphobia  A fear of being in public, usually because the person fears the embarrassment of a panic attack.
algorithm  A problem-solving rule or procedure that, when followed step by step, assures that a correct solution will be found.
all-or-none law  The principle that once a neuron reaches its firing threshold, a neural impulse travels at full strength along the entire length of its axon.
altruism  The helping of others without the expectation of a reward.
Alzheimer's disease  A brain disorder characterized by difficulty in forming new memories and by general mental deterioration.
amphetamines  Stimulants used to maintain alertness and wakefulness.
amygdala  A limbic system structure that evaluates information from the immediate environment, contributing to feelings of fear, anger, or relief.
anal stage  In Freud's theory, the stage of personality development, between ages 1 and 3, during which the child gains pleasure from defecation and faces a conflict over toilet training.
analysis of dreams  In psychoanalysis, the process by which the therapist interprets the symbolic, manifest content of dreams to reveal their true, latent content to the client.
analysis of free associations  In psychoanalysis, the process by which the therapist interprets the underlying meaning of the client's uncensored reports of anything that comes to mind.
analysis of resistances  In psychoanalysis, the process by which the therapist interprets client behaviors that interfere with therapeutic progress toward uncovering unconscious conflicts.
analysis of transference  In psychoanalysis, the process by which the therapist interprets the feelings expressed by the client toward the therapist as being indicative of the feelings typically expressed by the client toward important people in his or her personal life.
analysis of variance  A statistical technique used to determine whether the difference between two or more sets of scores is statistically significant.
analytic introspection  A research method in which highly trained participants report the contents of their conscious mental experiences.
anorexia nervosa  An eating disorder marked by self-starvation.
antianxiety drugs  Psychoactive drugs that are used to treat anxiety disorders.
antidepressant drugs  Psychoactive drugs that are used to treat major depression.
antimania drugs  Psychoactive drugs, most notably lithium carbonate, that are used to treat bipolar disorder.
antipsychotic drugs  Psychoactive drugs that are used to treat schizophrenia.
antisocial personality disorder  A personality disorder marked by impulsive, manipulative, often criminal behavior, without any feelings of guilt in the perpetrator.
anxiety disorder  A psychological disorder marked by persistent anxiety that disrupts everyday functioning.
applied research  Research aimed at improving the quality of life and solving practical problems.
aptitude test  A test designed to predict a person's potential to benefit from instruction in a particular academic or vocational setting.
archetypes  In Jung's theory, inherited images that are passed down from our prehistoric ancestors and that reveal themselves as universal symbols in art, dreams, and religion.
archival research  The systematic examination of collections of letters, manuscripts, tape recordings, video recordings, or other records.
arousal motive  The motive to maintain an optimal level of physiological activation.
artificial intelligence (AI)  The field that integrates computer science and cognitive psychology in studying information processing through the design of computer programs that appear to exhibit intelligence.
assertiveness training  A form of social-skills training that teaches clients to express their feelings constructively.
assimilation  The cognitive process that interprets new information in light of existing schemas.
association areas  Regions of the cerebral cortex that integrate information from the primary cortical areas and other brain areas.
atherosclerosis  The narrowing of arteries caused by the accumulation of cholesterol deposits.
attention  The process by which the individual focuses awareness on certain contents of consciousness while ignoring others.
attitude  An evaluation, containing cognitive, emotional, and behavioral components, of an idea, event, object, or person.
audition  The sense of hearing.
auditory cortex  The area of the temporal lobes that processes sounds.
auditory nerve  The nerve that conducts impulses from the cochlea to the brain.
authoritative parenting  An effective style of parenting, in which the parent is warm and loving, yet sets well-defined limits that he or she enforces in an appropriate manner.
autism  An often severe developmental disorder that includes deficiencies in social relationships, disordered communication, and repetitive and restricted patterns of behavior.
automatic processing  Information processing that requires less conscious awareness and mental effort, and that does not interfere with the performance of other ongoing activities.
autonomic nervous system  The division of the peripheral nervous system that controls automatic, involuntary physiological processes.
autonomy versus shame and doubt  Erikson's developmental stage in which success is achieved by gaining a degree of independence from one's parents.
availability heuristic  In decision making, the tendency to estimate the probability of an event by how easily relevant instances of it come to mind.
aversion therapy  A form of behavior therapy that inhibits maladaptive behavior by pairing a stimulus that normally elicits a maladaptive response with an unpleasant stimulus.
avoidance learning  Learning to prevent the occurrence of an aversive stimulus by giving an appropriate response to a warning stimulus.
axon  The part of the neuron that conducts neural impulses to glands, muscles, or other neurons.
axonal conduction  The transmission of a neural impulse along the length of an axon.
barbiturates  Depressants used to induce sleep or anesthesia.
basal metabolic rate  The rate at which the body burns calories just to keep itself alive.
basic research  Research aimed at finding answers to questions out of theoretical interest or intellectual curiosity.
basilar membrane  A membrane running the length of the cochlea that contains the auditory receptor (hair) cells.
behavioral contingencies  Relationships between behaviors and their consequences, such as positive reinforcement, negative reinforcement, extinction, and punishment.
behavioral genetics  The study of the effects of heredity and life experiences on behavior.
behavioral neuroscience  The field that studies the physiological bases of human and animal behavior and mental processes.
behavioral perspective  The psychological viewpoint, descended from behaviorism, that stresses the importance of studying the effects of learning and environmental factors on overt behavior.
behavioral preparedness  The degree to which members of a species are innately prepared to learn particular behaviors.
behaviorism  The early school of psychology that rejected the study of mental processes in favor of the study of overt behavior.
behavior therapy  The therapeutic application of the principles of learning to change maladaptive behaviors.
binocular cues  Depth perception cues that require input from the two eyes.
biofeedback  A form of operant conditioning that enables an individual to learn to control a normally involuntary physiological process or to gain better control of a normally voluntary one when provided with visual or auditory information indicating the state of that response.
biological rhythms  Repeating cycles of physiological changes.
biopsychological perspective  The psychological viewpoint that stresses the relationship of physiological factors to behavior and mental processes.
bipolar disorder  A mood disorder marked by periods of mania alternating with longer periods of major depression.
blocking  The process by which a neutral stimulus paired with a conditioned stimulus that already elicits a conditioned response fails to become a conditioned stimulus.
borderline personality disorder (BPD)  A personality disorder marked by impulsivity, unstable moods, an inconsistent sense of identity, and difficulty maintaining intimate relationships.
brain  The structure of the central nervous system that is located in the skull and plays important roles in sensation, movement, and information processing.
brightness constancy  The perceptual process that makes an object maintain a particular level of brightness despite changes in the amount of light reflected from it.
Broca's area  The region of the frontal lobe responsible for the production of speech.
bulimia nervosa  An eating disorder marked by binging and purging.
bystander intervention  The act of helping someone who is in immediate need of aid.
caffeine  A stimulant used to increase mental alertness.
cannabis sativa  A hallucinogen derived from the hemp plant and ingested in the form of marijuana or hashish.
Cannon-Bard theory  The theory that an emotion is produced when an event or object is perceived by the thalamus, which conveys this information simultaneously to the cerebral cortex and the skeletal muscles and autonomic nervous system.
case study  An in-depth study of an individual.
catatonic schizophrenia  A type of schizophrenia marked by unusual motor behavior, such as bizarre actions, extreme agitation, or immobile stupor.
catharsis  In psychoanalysis, the release of repressed emotional energy as a consequence of insight into the unconscious causes of one's psychological problems.
causal attribution  The cognitive process by which we infer the causes of both our own and other people's social behavior.
causation  An effect of one or more variables on another variable.
central nervous system  The division of the nervous system consisting of the brain and the spinal cord.
cerebellum  A brain stem structure that controls the timing of well-learned movements.
cerebral cortex  The outer covering of the brain.
cerebral hemispheres  The left and right halves of the cerebrum.
cerebral palsy  A movement disorder caused by brain damage and that is sometimes accompanied by mental retardation.
chaining  An operant conditioning procedure used to establish a desired sequence of behaviors by positively reinforcing each behavior in the sequence.
childhood  The period that extends from birth until the onset of puberty.
circadian rhythms  24-hour cycles of physiological changes, most notably the sleep-wake cycle.
clairvoyance  The alleged ability to perceive objects or events without any sensory contact with them.
classical conditioning  A form of learning in which a neutral stimulus comes to elicit a response after being associated with a stimulus that already elicits that response.
clinical psychology  The field that applies psychological principles to the prevention, diagnosis, and treatment of psychological disorders.
cocaine  A stimulant used to induce mental alertness and euphoria.
cochlea  The spiral, fluid-filled structure of the inner ear that contains the receptor cells for hearing.
coefficient of correlation  A statistic that assesses the degree of association between two or more variables.
cognitive appraisal  The subjective interpretation of the severity of a stressor.
cognitive-appraisal theory  The theory that one's emotion at a given time depends on one's interpretation of the situation one is in.
cognitive dissonance theory  Leon Festinger's theory that attitude change is motivated by the desire to relieve the unpleasant state of arousal caused when one holds cognitions and/ or behaviors that are inconsistent with each other.
cognitive-evaluation theory  The theory that a person's intrinsic motivation will increase when a reward is perceived as a source of information but will decrease when a reward is perceived as an attempt to exert control.
cognitive neuroscience  The study of the neurological bases of cognitive processes.
cognitive perspective  The psychological viewpoint that favors the study of how the mind organizes perceptions, processes information, and interprets experiences.
cognitive psychology  The psychological viewpoint that favors the study of how the mind organizes perceptions, processes information, and interprets experiences.
cognitive therapy  A type of therapy, developed by Aaron Beck, that aims at eliminating exaggerated negative beliefs about oneself, the world, or the future.
cohort  A group of people of the same age group.
collective efficacy  People's perception that with collaborative effort the group will obtain its desired outcome.
collective unconscious  In Jung's theory, the unconscious mind that is shared by all human beings and that contains archetypal images passed down from our prehistoric ancestors.
color afterimage  A visual image that persists after the removal of a visual stimulus.
color blindness  The inability to distinguish between certain colors, most often red and green.
companionate love  Love characterized by feelings of affection and commitment to a relationship with another person.
comparative psychology  The field that studies similarities and differences in the physiology, behaviors, and abilities of different species of animals, including human beings.
computed tomography (CT)  A brain-scanning technique that relies on X rays to construct computer-generated images of the brain or body.
computer-assisted instruction  The use of computer programs to provide programmed instruction.
concept  A category of objects, events, qualities, or relations that share certain features.
concrete operational stage  The Piagetian stage, extending from 7 to 11 years of age, during which the child learns to reason logically about objects that are physically present.
conditioned response (CR)  In classical conditioning, the learned response given to a particular conditioned stimulus.
conditioned stimulus (CS)  In classical conditioning, a neutral stimulus that comes to elicit a particular conditioned response after being paired with a particular unconditioned stimulus that already elicits that response.
conditioned taste aversion  A taste aversion induced by pairing a taste with gastrointestinal distress.
conduction deafness  Hearing loss usually caused by blockage of the auditory canal, damage to the eardrum, or deterioration of the ossicles of the middle ear.
cones  Receptor cells of the retina that play an important role in daylight vision and color vision.
conformity  Behaving in accordance with group expectations with little or no overt pressure to do so.
confounding variable  A variable whose unwanted effect on the dependent variable might be confused with that of the independent variable.
conscious mind  The level of consciousness that includes the mental experiences that we are aware of at a given moment.
consciousness  Awareness of one's own mental activity, including thoughts, feelings, and sensations.
conservation  The realization that changing the form of a substance does not change its amount.
constructive recall  The distortion of memories by adding, dropping, or changing details to fit a schema.
context-dependent memory  The tendency for recall to be best when the environmental context present during the encoding of a memory is also present during attempts at retrieving it.
continuous schedule of reinforcement  A schedule of reinforcement that provides reinforcement for each instance of a desired response.
control group  The participants in an experiment who are not exposed to the experimental condition of interest.
controlled processing  Information processing that involves conscious awareness and mental effort, and that interferes with the performance of other ongoing activities.
conventional level  In Kohlberg's theory, the level of moral reasoning characterized by concern with upholding laws and conventional values and by favoring obedience to authority.
convergent thinking  The cognitive process that focuses on finding conventional solutions to problems.
cornea  The round, transparent area in the front of the sclera that allows light to enter the eye.
corpus callosum  A thick bundle of axons that provides a means of communication between the cerebral hemispheres, which is severed in so-called split-brain surgery.
correlation  The degree of relationship between two or more variables.
correlational research  Research that studies the degree of relationship between two or more variables.
correlational statistics  Statistics that determine the relationship between two variables.
counseling psychology  The field that applies psychological principles to help individuals deal with problems of daily living, generally less serious ones than those treated by clinical psychologists.
counterconditioning  A behavior therapy technique that applies the principles of classical conditioning to replace unpleasant emotional responses to stimuli with more pleasant ones.
creativity  A form of problem solving that generates novel, socially valued solutions to problems.
critical period  A period in childhood when experience with language produces optimal language acquisition.
cross-cultural psychology  An approach that tries to determine the extent to which research findings about human psychology hold true across cultures.
cross-sectional research  A research design in which groups of participants of different ages are compared at the same point in time.
crystallized intelligence  The form of intelligence that reflects knowledge acquired through schooling and in everyday life.
cultural-familial retardation  Mental retardation apparently caused by social or cultural deprivation.
cultural psychology  An approach that studies how cultural factors affect human behavior and mental experience.
dark adaptation  The process by which the eyes become more sensitive to light when under low illumination.
debriefing  A procedure, after the completion of a research study, that informs participants of the purpose of the study and aims to remove any physical or psychological distress caused by participation.
decay theory  The theory that forgetting occurs because memories naturally fade over time.
decision making  A form of problem solving in which one tries to make the best choice from among alternative judgments or courses of action.
declarative memory  The long-term memory system that contains memories of facts.
deep structure  The underlying meaning of a statement.
defense mechanism  In Freud's theory, a process that distorts reality to prevent the individual from being overwhelmed by anxiety.
deindividuation  The process by which group members become less aware of themselves as individuals and less concerned about being socially evaluated.
deinstitutionalization  The movement toward treating people with psychological disorders in community settings instead of mental hospitals.
dendrites  The branchlike structures of the neuron that receive neural impulses.
dependent variable  A variable showing the effect of the independent variable.
depressants  Psychoactive drugs that inhibit activity in the central nervous system.
depth perception  The perception of the relative distance of objects.
descriptive research  Research that involves the recording of behaviors that have been observed systematically.
descriptive statistics  Statistics that summarize research data.
determinism  The assumption that every event has physical, potentially measurable, causes.
developmental psychology  The field that studies physical, perceptual, cognitive, and psychosocial changes across the life span.
diathesis-stress viewpoint  The assumption that psychological disorders are consequences of the interaction of a biological, inherited predisposition (diathesis) and exposure to stressful life experiences.
difference threshold  The minimum amount of change in stimulation that can be detected.
differential psychology  The field of psychology that studies individual differences in physical, personality, and intellectual characteristics.
discriminative stimulus  In operant conditioning, a stimulus that indicates the likelihood that a particular response will be reinforced.
disorganized schizophrenia  A type of schizophrenia marked by severe personality deterioration and extremely bizarre behavior.
disparagement theory  The theory that humor is amusing when it makes one feel superior to other people.
displacement  

1. In psychoanalytic theory, the defense mechanism that involves expressing feelings toward a person who is less threatening than the person who is the true target of those feelings.

2. The characteristic of language marked by the ability to refer to objects and events that are not present.


dissociation  A state in which the mind is split into two or more independent streams of consciousness.
dissociative amnesia  The inability to recall personally significant memories.
dissociative disorder  A psychological disorder in which thoughts, feelings, and memories become separated from conscious awareness.
dissociative fugue  Memory loss characteristic of dissociative amnesia as well as the loss of one's identity and fleeing from one's prior life.
dissociative identity disorder  A dissociative disorder, more commonly known as multiple personality disorder, in which the person has two or more distinct personalities that alternate with one another.
distributed practice  Spreading out the memorization of information or the learning of a motor skill over several sessions.
divergent thinking  The cognitive process by which an individual freely considers a variety of potential solutions to artistic, literary, scientific, or practical problems.
double-blind technique  A procedure that controls experimenter bias and participant bias by preventing experimenters and participants from knowing which participants have been assigned to particular conditions.
Down syndrome  A form of mental retardation, associated with certain physical deformities, that is caused by an extra, third chromosome on the 21st pair.
dream  A storylike sequence of visual images, usually occurring during REM sleep.
drive  A state of psychological tension induced by a need.
drive-reduction theory  The theory that behavior is motivated by the need to reduce drives such as sex or hunger.
echoic memory  Auditory sensory memory, which lasts up to 4 or more seconds.
educational psychology  The field that applies psychological principles to help improve curriculum, teaching methods, and administrative procedures.
ego  In Freud's theory, the part of the personality that helps the individual adapt to external reality by making compromises between the id, the superego, and the environment.
egocentrism  The inability to perceive reality from the perspective of another person.
elaboration likelihood model  A theory of persuasion that considers the extent to which messages take a central route or a peripheral route.
elaborative rehearsal  Actively organizing new information to make it more meaningful, and integrating it with information already stored in long-term memory.
Electra complex  A term used by some psychoanalysts, but not by Freud, to refer to the Oedipus complex in girls.
electroconvulsive therapy (ECT)  A biopsychological therapy that uses brief electric currents to induce brain seizures in victims of major depression.
electroencephalograph (EEG)  A device used to record patterns of electrical activity produced by neuronal activity in the brain.
embryonic stage  The prenatal period that lasts from the end of the second week through the eighth week.
emotion  A motivated state marked by physiological arousal, expressive behavior, and cognitive experience.
empiricism  The philosophical position that true knowledge comes through the senses.
encoding  The conversion of information into a form that can be stored in memory.
encoding specificity  The principle that recall will be best when cues that were associated with the encoding of a memory are also present during attempts at retrieving it.
endocrine system  Glands that secrete hormones into the bloodstream.
endorphins  Neurotransmitters that play a role in pleasure, pain relief, and other functions.
engineering psychology  The field that applies psychological principles to the design of equipment and instruments.
engram  A memory trace in the brain.
entactogens  A new category of psychoactive drugs that have unique effects intermediate to those associated with hallucinogens and stimulants.
environmental psychology  The field that applies psychological principles to help improve the physical environment, including the design of buildings and the reduction of noise.
episodic memory  The subsystem of declarative memory that contains memories of personal experiences tied to particular times and places.
escape learning  Learning to perform a behavior that terminates an aversive stimulus, as in negative reinforcement.
ethnic psychology  The field that employs culturally appropriate methods to describe the experience of members of groups that historically have been underrepresented in psychology.
ethology  The study of animal behavior in the natural environment.
ethyl alcohol  A depressant found in beverages and commonly used to reduce social inhibitions.
eugenics  The practice of encouraging supposedly superior people to reproduce, while preventing supposedly inferior people from reproducing.
evolutionary psychology  The study of the evolution of behavior through natural selection.
existential psychology  A branch of humanistic psychology that studies how individuals respond to the basic philosophical issues of life, such as death, meaning, freedom, and isolation.
experimental group  The participants in an experiment who are exposed to the experimental condition of interest.
experimental method  Research that manipulates one or more variables, while controlling other factors, to determine the effects on one or more other variables.
experimental psychology  The field primarily concerned with laboratory research on basic psychological processes, including perception, learning, memory, thinking, language, motivation, and emotion.
experimenter bias effect  The tendency of experimenters to let their expectancies alter the way they treat their participants.
explanatory style  The tendency to explain events optimistically or pessimistically.
explicit memory  Conscious recollection of general information or personal experiences.
external validity  The extent to which the results of a research study can be generalized to other people, animals, or settings.
extinction  

1. In classical conditioning, the gradual disappearance of the conditioned response when the conditioned stimulus is repeatedly presented without being paired with the unconditioned stimulus.

2. In operant conditioning, the gradual disappearance of a response that is no longer followed by a reinforcer.


extrasensory perception (ESP)  The alleged ability to perceive events without the use of sensory receptors.
extravert  A person who is socially outgoing and prefers to pay attention to the external environment.
extrinsic motivation  The desire to perform a behavior in order to obtain an external reward, such as praise, grades, or money.
eyewitness testimony  Witnesses' recollections about events, most notably about criminal activity.
facial-feedback theory  The theory that particular facial expressions induce particular emotional experiences.
factor analysis  A statistical technique that determines the degree of correlation between performances on various tasks to determine the extent to which they reflect particular underlying characteristics, which are known as factors.
family therapy  A form of group therapy that encourages the constructive expression of feelings and the establishment of rules that family members agree to follow.
feature-detector theory  The theory that we construct perceptions of stimuli from activity in neurons of the brain that are sensitive to specific features of those stimuli.
fetal alcohol syndrome  A disorder, marked by physical defects and mental retardation, that can afflict the offspring of women who drink alcohol during pregnancy.
fetal stage  The prenatal period that lasts from the end of the eighth week through birth.
fight-or-flight response  A state of physiological arousal that enables us to meet sudden threats by either confronting them or running away from them.
figure-ground perception  The distinguishing of an object (the figure) from its surroundings (the ground).
fixation  In Freud's theory, the failure to mature beyond a particular stage of psychosexual development.
fixed-interval schedule of reinforcement  A partial schedule of reinforcement that provides reinforcement for the first desired response made after a set length of time.
fixed-ratio schedule of reinforcement  A partial schedule of reinforcement that provides reinforcement after a set number of desired responses.
flashbulb memory  A vivid, long-lasting memory of a surprising, important, emotionally arousing event.
flooding  An extinction procedure in which a phobic client is exposed to a stimulus that evokes intense anxiety.
fluid intelligence  The form of intelligence that reflects reasoning ability, memory capacity, and speed of information processing.
foot-in-the-door technique  Increasing the likelihood that someone will comply with a request by first getting him or her to comply with a smaller one.
forensic psychology  The field that applies psychological principles to improve the legal system, including the work of police and juries.
forgetting  The failure to retrieve information from memory.
forgetting curve  A graph showing that forgetting is initially rapid and then slows.
formal operational stage  The Piagetian stage, beginning at about age 11, marked by the ability to use abstract reasoning and to solve problems by testing hypotheses.
fovea  A small area at the center of the retina that contains only cones and provides the most acute vision.
framing effects  In decision making, biases introduced into the decision-making process by presenting an issue or situation in a certain manner.
frequency histogram  A graph that displays the frequency of scores as bars.
frequency polygon  A graph that displays the frequency of scores by connecting points representing them above each score.
frequency theory  The theory of pitch perception that assumes that the basilar membrane vibrates as a whole in direct proportion to the frequency of the sound waves striking the eardrum.
frontal lobe  A lobe of the cerebral cortex responsible for motor control and higher mental processes.
frustration-aggression hypothesis  The assumption that frustration causes aggression.
functional fixedness  The inability to realize that a problem can be solved by using a familiar object in an unusual way.
functionalism  The early school of psychology that studied how the conscious mind helps the individual adapt to the environment.
fundamental attribution error  The bias to attribute other people's behavior to dispositional factors.
gate-control theory  The theory that pain impulses can be blocked by the closing of a neuronal gate in the spinal cord.
gender roles  The behaviors that are considered appropriate for females or males in a given culture.
gender schema theory  A theory of gender-role development that combines aspects of social learning theory and the cognitive perspective.
general adaptation syndrome  As first identified by Hans Selye, the body's stress response, which includes the stages of alarm, resistance, and exhaustion.
generalized anxiety disorder  An anxiety disorder marked by a persistent state of anxiety that exists independently of any particular stressful situation.
generativity  The characteristic of language marked by the ability to combine words in novel, meaningful ways.
generativity versus stagnation  Erikson's developmental stage in which success is achieved by becoming less self-absorbed and more concerned with the well-being of others.
genital stage  In Freud's theory, the last stage of personality development, associated with puberty, during which the individual develops erotic attachments to others.
genotype  An individual's genetic inheritance.
germinal stage  The prenatal period that lasts from conception through the second week.
Gestalt psychology  The early school of psychology that claimed that we perceive and think about wholes rather than simply combinations of separate elements.
Gestalt therapy  A type of humanistic therapy, developed by Fritz Perls, that encourages clients to become aware of their true feelings and to take responsibility for their own actions.
glial cell  A kind of cell that provides a physical support structure for the neurons, supplies them with nutrition, removes neuronal metabolic waste materials, facilitates the transmission of messages by neurons, and helps regenerate damaged neurons in the peripheral nervous system.
gonads  The male and female sex glands.
grammar  The set of rules that governs the proper use and combination of language symbols.
group  A collection of two or more persons who interact and have mutual influence on each other.
groupthink  The tendency of small, cohesive groups to place unanimity ahead of critical thinking in making decisions.
Guilty Knowledge Test  A method that assesses lying by measuring physiological arousal in response to information that is relevant to a transgression and physiological arousal in response to information that is irrelevant to that transgression.
gustation  The sense of taste, which detects molecules of substances dissolved in the saliva.
hallucinogens  Psychoactive drugs that induce extreme alterations in consciousness, including visual hallucinations, a sense of timelessness, and feelings of depersonalization.
health psychology  The field that applies psychological principles to the prevention and treatment of physical illness.
heritability  The proportion of variability in a trait across a population attributable to genetic differences among members of the population.
heuristic  A general principle that guides problem solving, though it does not guarantee a correct solution.
hidden observer  Ernest Hilgard's term for the part of the hypnotized person's consciousness that is not under the control of the hypnotist but is aware of what is taking place.
hierarchy of needs  Abraham Maslow's arrangement of needs in the order of their motivational priority, ranging from physiological needs to the needs for self-actualization and transcendence.
higher-order conditioning  In classical conditioning, the establishment of a conditioned response to a neutral stimulus that has been paired with an existing conditioned stimulus.
hippocampus  A limbic system structure that contributes to the formation of memories.
holophrastic speech  The use of single words to represent whole phrases or sentences.
homeostasis  A steady state of physiological equilibrium.
hormones  Chemicals, secreted by endocrine glands, that play a role in a variety of functions, including synaptic transmission.
humanistic perspective  The psychological viewpoint that holds that the proper subject matter of psychology is the individual's subjective mental experience of the world.
hypermnesia  The hypnotic enhancement of recall.
hyperopia  Visual farsightedness, which is caused by a shortened eyeball.
hypnosis  An induced state of consciousness in which one person responds to suggestions by another person for alterations in perception, thinking, and behavior.
hypothalamus  A limbic system structure that, through its effects on the pituitary gland and the autonomic nervous system, helps to regulate aspects of motivation and emotion, including eating, drinking, sexual behavior, body temperature, and stress responses.
hypothesis  A testable prediction about the relationship between two or more events or characteristics.
iconic memory  Visual sensory memory, which lasts up to about a second.
id  In Freud's theory, the part of the personality that contains inborn biological drives and that seeks immediate gratification.
identity versus role confusion  Erikson's developmental stage in which success is achieved by establishing a sense of personal identity.
implicit memory  Recollection of previous experiences demonstrated through behavior, rather than through conscious, intentional remembering.
incentive  An external stimulus that pulls an individual toward a goal.
incongruity theory  The theory that humor is amusing when it brings together incompatible ideas in a surprising outcome that violates one's expectations.
independent variable  A variable manipulated by the experimenter to determine its effect on another, dependent, variable.
industrial/ organizational psychology  The field that applies psychological principles to improve productivity in businesses, industries, and government agencies.
industry versus inferiority  Erikson's developmental stage in which success is achieved by developing a sense of competency.
infancy  The period that extends from birth through 2 years of age.
inferential statistics  Statistics used to determine whether changes in a dependent variable are caused by an independent variable.
information-processing model  The view that the processing of memories involves encoding, storage, and retrieval.
initiative versus guilt  Erikson's developmental stage in which success is achieved by behaving in a spontaneous but socially appropriate way.
insanity  A legal term attesting that a person is not responsible for his or her own actions, including criminal behavior.
insight  An approach to problem solving that depends on mental manipulation of information rather than overt trial and error, and produces sudden solutions to problems.
insomnia  Chronic difficulty in either falling asleep or staying asleep.
instinct  A complex, inherited behavior pattern characteristic of a species.
instinctive drift  The reversion of animals to behaviors characteristic of their species even when being reinforced for performing other behaviors.
instrumental conditioning  A form of learning in which a behavior becomes more or less probable, depending on its consequences.
integrity versus despair  Erikson's developmental stage in which success is achieved by reflecting back on one's life and finding that it has been meaningful.
intelligence  The global capacity to act purposefully, to think rationally, and to deal effectively with the environment.
intelligence quotient (IQ)  1. Originally, the ratio of mental age to chronological age; that is, MA/ CA 3 100. 2. Today, the score on an intelligence test, calculated by comparing a person's performance to norms for her or his age group.
intelligence test  A test that assesses overall mental ability.
interference theory  The theory that forgetting results from some memories interfering with the ability to remember other memories.
internal validity  The extent to which changes in a dependent variable can be attributed to one or more independent variables rather than to a confounding variable.
interneuron  A neuron that conveys messages between neurons in the brain or spinal cord.
intimacy versus isolation  Erikson's developmental stage in which success is achieved by establishing a relationship with a strong sense of emotional attachment and personal commitment.
intrinsic motivation  The desire to perform a behavior for its own sake.
introvert  A person who is socially reserved and prefers to pay attention to his or her private mental experiences.
in vivo desensitization  A form of counterconditioning that trains the client to maintain a state of relaxation in the presence of anxiety-inducing stimuli.
iris  The donut-shaped band of muscles behind the cornea that gives the eye its color and controls the size of the pupil.
James-Lange theory  The theory that specific patterns of physiological changes evoke specific emotional experiences.
just noticeable difference (jnd)  Weber and Fechner's term for the difference threshold.
kinesthetic sense  The sense that provides information about the position of the joints, the degree of tension in the muscles, and the movement of the arms and legs.
language  A formal system of communication involving symbols --whether spoken, written, or gestured-- and rules for combining them.
latency stage  In Freud's theory, the stage, between age 5 and puberty, during which there is little psychosexual development.
latent content  Sigmund Freud's term for the true, though disguised, meaning of a dream.
latent learning  Learning that occurs without the reinforcement of overt behavior.
law of effect  Edward Thorndike's principle that a behavior followed by a satisfying state of affairs is strengthened and a behavior followed by an annoying state of affairs is weakened.
learned helplessness  A feeling of futility caused by the belief that one has little or no control over events in one's life, which can make one stop trying and become depressed.
learning  A relatively permanent change in knowledge or behavior resulting from experience.
lens  The transparent structure behind the pupil that focuses light onto the retina.
levels of processing theory  The theory that the "depth" at which we process information determines how well it is encoded, stored, and retrieved.
libido  Freud's term for the sexual energy of the id.
limbic system  A group of brain structures that, through their influence on emotion, motivation, and memory, promote the survival of the individual and, as a result, the continuation of the species.
line graph  A graph used to plot data showing the relationship between independent and dependent variables in an experiment.
linguistic relativity hypothesis  Whorf's hypothesis that one's perception of the world is molded by one's language.
link method  A mnemonic device that involves connecting, in sequence, images of items to be memorized, to make them easier to recall.
logical concept  A concept formed by identifying the specific features possessed by all things that the concept applies to.
longitudinal research  A research design in which the same group of participants is tested or observed repeatedly over a period of time.
long-term memory  The stage of memory that can store a virtually unlimited amount of information relatively permanently.
long-term potentiation  A phenomenon related to the facilitation of neural impulses, in which synaptic transmission of impulses is made more efficient by brief electrical stimulation of specific neural pathways.
loudness perception  The subjective experience of the intensity of a sound, which corresponds most closely to the amplitude of the sound waves composing it.
LSD  A hallucinogen derived from a fungus that grows on rye grain.
lucid dreaming  The ability to be aware that one is dreaming and to direct one's dreams.
magnetic resonance imaging (MRI)  A brain-scanning technique that relies on strong magnetic fields to construct computer-generated images of the brain or body.
maintenance rehearsal  Repeating information to oneself to keep it in short-term memory.
major depression  A mood disorder marked by depression so intense and prolonged that the person may be unable to function in everyday life.
mania  A mood disorder marked by euphoria, hyperactivity, grandiose ideas, annoying talkativeness, unrealistic optimism, and inflated self-esteem.
manifest content  Sigmund Freud's term for the verbally reported dream.
massed practice  Cramming the memorization of information or the learning of a motor skill into one session.
maturation  The sequential unfolding of inherited predispositions in physical and motor development.
mean  The arithmetic average of a set of scores.
measurement  The use of numbers to represent events or characteristics.
measure of central tendency  A statistic that represents the "typical" score in a set of scores.
measure of variability  A statistic describing the degree of dispersion in a set of scores.
median  The middle score in a set of scores that have been ordered from lowest to highest.
medulla  A brain stem structure that regulates breathing, heart rate, blood pressure, and other life functions.
memory  The process by which information is acquired, stored in the brain, later retrieved, and eventually possibly forgotten.
menarche  The beginning of menstruation, usually occurring between the ages of 11 and 13.
mental giftedness  Intellectual superiority marked by an IQ above 130 and exceptionally high scores on achievement tests in specific subjects, such as mathematics.
mental retardation  Intellectual deficiency marked by an IQ below 70 and difficulties performing in everyday life.
mental set  A tendency to use a particular problem-solving strategy that has succeeded in the past but that may interfere with solving a problem requiring a new strategy.
mental telepathy  The alleged ability to perceive the thoughts of others without any sensory contact with them.
meta-analysis  A technique that combines the results of many similar studies to determine the effect size of a particular kind of independent variable.
method of loci  A mnemonic device in which items to be recalled are associated with landmarks in a familiar place and then recalled during a mental walk from one landmark to another.
method of savings  The assessment of memory by comparing the time or number of trials needed to memorize a given amount of information and the time or number of trials needed to memorize it again at a later time.
mnemonic devices  Techniques for organizing information to be memorized to make it easier to remember.
mode  The score that occurs most frequently in a set of scores.
monocular cues  Depth perception cues that require input from only one eye.
mood disorder  A psychological disorder marked by prolonged periods of extreme depression or elation, often unrelated to the person's current situation.
moon illusion  The misperception that the moon is larger when it is at the horizon than when it is overhead.
moral therapy  An approach to therapy, developed by Philippe Pinel, that provided mental patients with humane treatment.
morphemes  The smallest meaningful units of language.
motivation  The psychological process that arouses, directs, and maintains behavior toward a goal.
motor cortex  The area of the frontal lobes that controls specific voluntary body movements.
motor neuron  A neuron that sends messages from the central nervous system to smooth muscles, cardiac muscle, or skeletal muscles.
myelin  A white fatty substance that forms sheaths around certain axons and increases the speed of neural impulses.
myopia  Visual nearsightedness, which is caused by an elongated eyeball.
narcolepsy  A condition in which an awake person suffers from repeated, sudden, and irresistible REM sleep attacks.
nativism  The philosophical position that heredity provides individuals with inborn knowledge and abilities.
natural concept  A concept, typically formed through everyday experience, whose members possess some, but not all, of a common set of features.
naturalistic observation  The recording of the behavior of people or animals in their natural environments, with little or no intervention by the researcher.
need  A motivated state caused by physiological deprivation, such as a lack of food or water.
negative correlation  A correlation in which variables tend to change values in opposite directions.
negative reinforcement  In operant conditioning, an increase in the probability of a behavior that is followed by the removal of an aversive stimulus.
negative skew  A graph that has scores bunching up toward the positive end of the horizontal axis.
negative state relief theory  The theory that we engage in prosocial behavior to relieve our own state of emotional distress at another's plight.
neodissociation theory  The theory that hypnosis induces a dissociated state of consciousness.
nerve  A bundle of axons that conveys information to or from the central nervous system.
nerve deafness  Hearing loss caused by damage to the hair cells of the basilar membrane, the axons of the auditory nerve, or the neurons of the auditory cortex.
nervous system  The chief means of communication in the body.
neuron  A cell specialized for the transmission of information in the nervous system.
neurotransmitters  Chemicals secreted by neurons that provide the means of synaptic transmission.
nicotine  A stimulant used to regulate physical and mental arousal.
nightmare  A frightening dream occurring during REM sleep.
night terror  A frightening NREM experience, common in childhood, in which the individual may suddenly sit up, let out a bloodcurdling scream, speak incoherently, and quickly fall back to sleep, yet usually fails to recall it on awakening.
norm  A score, based on the test performances of large numbers of participants, that is used as a standard for assessing the performances of test takers.
normal curve  A bell-shaped graph representing a hypothetical frequency distribution for a given characteristic.
NREM sleep  The stages of sleep not associated with rapid eye movements and marked by relatively little dreaming.
null hypothesis  The prediction that the independent variable will have no effect on the dependent variable in an experiment.
obedience  Following orders given by an authority.
obesity  A body weight more than 20 percent above the norm for one's height and build.
object permanence  The realization that objects exist even when they are no longer visible.
observational learning  Learning a behavior by observing the consequences that others receive for performing it.
obsessive-compulsive disorder  An anxiety disorder in which the person has recurrent, intrusive thoughts (obsessions) and recurrent urges to perform ritualistic actions (compulsions).
occipital lobe  A lobe of the cerebral cortex responsible for processing vision.
Oedipus complex  In Freud's theory, a conflict, during the phallic stage, between the child's sexual desire for the parent of the opposite sex and fear of punishment from the same-sex parent.
olfaction  The sense of smell, which detects molecules carried in the air.
operant conditioning  B. F. Skinner's term for instrumental conditioning, a form of learning in which a behavior becomes more or less probable, depending on its consequences.
operational definition  The definition of behaviors or qualities in terms of the procedures used to measure or produce them.
opiates  Depressants, derived from opium, used to relieve pain or to induce a euphoric state of consciousness.
opponent-process theory  

1. The theory that color vision depends on red-green, blue-yellow, and black-white opponent processes in the brain.

2. The theory that the brain counteracts a strong positive or negative emotion by evoking an opposite emotional response.


optic chiasm  The point under the frontal lobes at which some axons from each of the optic nerves cross over to the opposite side of the brain.
optic nerve  The nerve, formed from the axons of ganglion cells, that carries visual impulses from the retina to the brain.
oral stage  In Freud's theory, the stage of personality development, between birth and age 1 year, during which the infant gains pleasure from oral activities and faces a conflict over weaning.
otolith organs  The vestibular organs that detect horizontal or vertical linear movement of the head.
ovaries  The female gonads, which secrete hormones that regulate the development of the female reproductive system and secondary sex characteristics.
overextension  The tendency to apply a word to more objects or actions than it actually represents.
overjustification theory  The theory that an extrinsic reward will decrease intrinsic motivation when a person attributes her or his performance to that reward.
overlearning  Studying material beyond the point of initial mastery.
overregularization  The application of a grammatical rule without making necessary exceptions to it.
panic disorder  An anxiety disorder marked by sudden, unexpected attacks of overwhelming anxiety, often associated with the fear of dying or "losing one's mind."
paranoid schizophrenia  A type of schizophrenia marked by hallucinations, delusions, suspiciousness, and argumentativeness.
parapsychology  The study of extrasensory perception, psychokinesis, and related phenomena.
parasympathetic nervous system  The division of the autonomic nervous system that calms the body and performs maintenance functions.
parietal lobe  A lobe of the cerebral cortex responsible for processing bodily sensations and perceiving spatial relations.
Parkinson's disease  A degenerative disease of the dopamine pathway, which causes marked disturbances in motor behavior.
partial schedule of reinforcement  A schedule of reinforcement that reinforces some, but not all, instances of a desired response.
participant bias  The tendency of people who know they are participants in a study to behave differently than they normally would.
participant modeling  A form of social-learning therapy in which the client learns to perform more adaptive behaviors by first observing the therapist model the desired behaviors.
passionate love  Love characterized by intense emotional arousal and sexual feelings.
Pearson's product-moment correlation (Pearson's ®)  Perhaps the most commonly used correlational statistic.
pegword method  A mnemonic device that involves associating items to be recalled with objects that rhyme with the numbers 1, 2, 3, and so on, to make the items easier to recall.
perceived control  The degree to which a person feels in control over life's stressors.
perception  The process that organizes sensations into meaningful patterns.
perception without awareness  The unconscious perception of stimuli that normally exceed the absolute threshold but fall outside our focus of attention.
peripheral nervous system  The division of the nervous system that conveys sensory information to the central nervous system and motor commands from the central nervous system to the skeletal muscles and internal organs.
personality  An individual's unique, relatively consistent pattern of thinking, feeling, and behaving.
personality disorder  A psychological disorder characterized by enduring, inflexible, maladaptive patterns of behavior.
personality psychology  The field that focuses on factors accounting for the differences in behavior and enduring personal characteristics among individuals.
personal unconscious  In Jung's theory, the individual's own unconscious mind, which contains repressed memories.
person-centered therapy  A type of humanistic therapy, developed by Carl Rogers, that helps clients find their own answers to their problems.
person perception  The process of making judgments about the personal characteristics of others.
persuasion  The attempt to influence the attitudes of other people.
phallic stage  In Freud's theory, the stage of personality development, between ages 3 and 5, during which the child gains pleasure from the genitals and must resolve the Oedipus complex.
phase advance  Shortening the sleep-wake cycle, as occurs when traveling from west to east.
phase delay  Lengthening the sleep-wake cycle, as occurs when traveling from east to west.
phenomenological psychology  A branch of humanistic psychology primarily concerned with the study of subjective mental experience.
phenotype  The overt expression of an individual's genotype (genetic inheritance) in their appearance or behavior.
phenylketonuria (PKU)  A hereditary enzyme deficiency that, if left untreated in the infant, causes mental retardation.
pheromone  An odorous chemical secreted by an animal that affects the behavior of other animals.
phi phenomenon  Apparent motion caused by the presentation of different visual stimuli in rapid succession.
phobia  An anxiety disorder marked by excessive or inappropriate fear.
phoneme  The smallest unit of sound in a language.
phonology  The study of the sounds that compose languages.
photopigments  Chemicals, including rhodopsin and iodopsin, that enable the rods and cones to generate neural impulses.
phrenology  A discredited technique for determining intellectual abilities and personality traits by examining the bumps and depressions of the skull.
physiological reactivity  The extent to which a person displays increases in heart rate, blood pressure, stress hormone secretion, and other physiological activity in response to stressors.
pie graph  A graph that represents data as percentages of a pie.
pineal gland  An endocrine gland that secretes a hormone that has a general tranquilizing effect on the body and that helps regulate biological rhythms.
pitch perception  The subjective experience of the highness or lowness of a sound, which corresponds most closely to the frequency of the sound waves that compose it.
pituitary gland  An endocrine gland that regulates many of the other endocrine glands by secreting hormones that affect the secretion of their hormones.
placebo  An inactive substance that might induce some of the effects of the drug for which it has been substituted.
place theory  The theory of pitch perception that assumes that hair cells at particular points on the basilar membrane are maximally responsive to sound waves of particular frequencies.
pleasure principle  The process by which the id seeks immediate gratification of its impulses.
polygraph test  The "lie detector" test, which assesses lying by measuring changing patterns of physiological arousal in response to particular questions.
pons  A brain stem structure that regulates the sleep-wake cycle.
population  A group of individuals who share certain characteristics.
positive correlation  A correlation in which variables tend to change values in the same direction.
positive reinforcement  In operant conditioning, an increase in the probability of a behavior that is followed by a desirable consequence.
positive skew  A graph that has scores bunching up toward the negative end of the horizontal axis.
positron-emission tomography (PET)  A brain-scanning technique that produces color-coded pictures showing the relative activity of different brain areas.
postconventional level  In Kohlberg's theory, the level of moral reasoning characterized by concern with obeying mutually agreed upon laws and by the need to uphold human dignity.
posthypnotic suggestions  Suggestions directing people to carry out particular behaviors or to have particular experiences after leaving hypnosis.
posttraumatic stress disorder  A syndrome of physical and psychological symptoms that appears as a delayed response after exposure to an extremely emotionally distressing event.
pragmatics  The relationship between language and its social context.
precognition  The alleged ability to perceive events in the future.
preconscious mind  The level of consciousness that contains feelings and memories that we are unaware of at the moment but can become aware of at will.
preconventional level  In Kohlberg's theory, the level of moral reasoning characterized by concern with the consequences that behavior has for oneself.
prejudice  A positive or negative attitude toward a person based on her or his membership in a particular group.
Premack principle  The principle that a more probable behavior can be used as a reinforcer for a less probable one.
preoperational stage  The Piagetian stage, extending from 2 to 7 years of age, during which the child's use of language becomes more sophisticated but the child has difficulty with the logical mental manipulation of information.
primary cortical areas  Regions of the cerebral cortex that serve motor or sensory functions.
primary reinforcer  In operant conditioning, an unlearned reinforcer, which satisfies a biological need such as air, food, or water.
proactive interference  The process by which old memories interfere with the ability to remember new memories.
problem solving  The thought process by which an individual overcomes obstacles to reach a goal.
procedural memory  The long-term memory system that contains memories of how to perform particular actions.
programmed instruction  A step-by-step approach, based on operant conditioning, in which the learner proceeds at his or her own pace through more and more difficult material and receives immediate knowledge of the results of each response.
progressive relaxation  A stress-management procedure that involves the successive tensing and relaxing of each of the major muscle groups of the body.
projection  In psychoanalytic theory, the defense mechanism that involves attributing one's own undesirable feelings to other people.
projective test  A Freudian personality test based on the assumption that individuals project their unconscious feelings when responding to ambiguous stimuli.
prosocial behavior  Behavior that helps others in need.
prosopagnosia  A form of visual agnosia in which an individual can identify details of faces but cannot recognize faces as wholes.
prototype  The best representative of a concept.
psychiatry  The field of medicine that diagnoses and treats psychological disorders by using medical or psychological forms of therapy.
psychic determinism  The Freudian assumption that all human behavior is influenced by unconscious motives.
psychoactive drugs  Chemicals that induce changes in mood, thinking, perception, and behavior by affecting neuronal activity in the brain.
psychoanalysis  

1. The early school of psychology that emphasized the importance of unconscious causes of behavior.

2. A type of psychotherapy, developed by Sigmund Freud, aimed at uncovering the unconscious causes of psychological disorders.


psychoanalytic perspective  The psychological viewpoint that is descended from psychoanalysis but places less emphasis on biological motives and more emphasis on the importance of interpersonal relationships.
psychokinesis (PK)  The alleged ability to control objects with the mind alone.
psychological hardiness  A personality characteristic marked by feelings of commitment, challenge, and control that promotes resistance to stress.
psychological test  A formal sample of a person's behavior, whether written or performed.
psychology  The science of behavior and mental processes.
psychoneuroimmunology  The interdisciplinary field that studies the relationship between psychological factors and physical illness.
psychopathology  The study of psychological disorders.
psychophysics  The study of the relationship between the physical characteristics of stimuli and the conscious psychological experiences that are associated with them.
psychosurgery  The treatment of psychological disorders by destroying brain tissue.
psychotherapy  The treatment of psychological disorders through psychological means generally involving verbal interaction with a professional therapist.
puberty  The period of rapid physical change that occurs during adolescence, including the development of the ability to reproduce sexually.
punishment  In operant conditioning, the process by which an aversive stimulus decreases the probability of a response that precedes it.
pupil  The opening at the center of the iris that controls how much light enters the eye.
random assignment  The assignment of participants to experimental and control conditions so that each participant is as likely to be assigned to one condition as to another.
random sampling  The selection of a sample from a population so that each member of the population has an equal chance of being included.
range  A statistic representing the difference between the highest and lowest scores in a set of scores.
rational-emotive behavior therapy (R-E-B-T)  A type of cognitive therapy, developed by Albert Ellis, that treats psychological disorders by forcing the client to give up irrational beliefs.
rationalism  The philosophical position that true knowledge comes through correct reasoning.
rationalization  Giving socially acceptable reasons for one's inappropriate behavior.
reaction formation  In psychoanalytic theory, the defense mechanism that involves a tendency to act in a manner opposite to one's true feelings.
reality principle  The process by which the ego directs the individual to express sexual and aggressive impulses in socially acceptable ways.
reciprocal determinism  Bandura's belief that personality traits, environmental factors, and overt behavior affect each other.
reflex  An automatic, involuntary motor response to sensory stimulation.
regression  In psychoanalytic theory, the defense mechanism that involves reverting to immature behaviors that have relieved anxiety in the past.
release theory  The theory that humor relieves anxiety caused by sexual or aggressive energy.
reliability  The extent to which a test gives consistent results.
REM sleep  The stage of sleep associated with rapid eye movements, an active brain-wave pattern, and vivid dreams.
replication  The repetition of a research study, usually with some alterations in its methods or setting, to determine whether the principles derived from that study hold up under similar circumstances.
representativeness heuristic  In decision making, the assumption that a small sample is representative of its population.
repression  In psychoanalytic theory, the defense mechanism that involves banishing threatening thoughts, feelings, and memories into the unconscious mind.
resting potential  The electrical charge of a neuron when it is not firing a neural impulse.
reticular formation  A diffuse network of neurons, extending through the brain stem, that helps maintain vigilance and an optimal level of brain arousal.
retina  The light-sensitive inner membrane of the eye that contains the receptor cells for vision.
retrieval  The recovery of information from memory.
retroactive interference  The process by which new memories interfere with the ability to remember old memories.
rods  Receptor cells of the retina that play an important role in night vision and peripheral vision.
sample  A group of participants selected from a population.
savant syndrome  The presence, in person with below-average general intelligence, of a talent --typically in art, music, or calculating-- developed beyond the person's level of functioning in other areas.
scatter plot  A graph of a correlational relationship.
schema  A cognitive structure that guides people's perception and information processing that incorporates the characteristics of particular persons, objects, events, procedures, or situations.
schema theory  The theory that long-term memories are stored as parts of schemas, which are cognitive structures that organize knowledge about events or objects.
schizophrenia  A class of psychological disorders characterized by grossly impaired social, emotional, cognitive, and perceptual functioning.
school psychology  The field that applies psychological principles to help improve the academic performance and social behavior of students in elementary, middle, and high schools.
scientific method  A source of knowledge based on the assumption that knowledge comes from the objective, systematic observation and measurement of particular variables and the events they affect.
scientific paradigm  A model that determines the appropriate goals, methods, and subject matter of a science.
sclera  The tough, white outer membrane of the eye.
seasonal affective disorder (SAD)  A mood disorder in which severe depression arises during a particular season, usually the winter.
secondary reinforcer  In operant conditioning, a neutral stimulus that becomes reinforcing after being associated with a primary reinforcer.
self-actualization  In Maslow's theory, the individual's predisposition to try to fulfill her or his potentials.
self-efficacy  In Bandura's theory, a person's belief that she or he can perform behaviors that are necessary to bring about a desired outcome.
self-fulfilling prophecy  The tendency for one person's expectations to influence another person to behave in accordance with them.
self-perception theory  The theory that we infer our attitudes from our behavior in the same way that we infer other people's attitudes from their behavior.
self-serving bias  The tendency to make dispositional attributions for one's successes and situational attributions for one's failures.
semanticity  The characteristic of language marked by the use of symbols to convey thoughts in a meaningful way.
semantic memory  The subsystem of declarative memory that contains general information about the world.
semantic network theory  The theory that memories are stored as nodes interconnected by links that represent their relationships.
semantics  The study of how language conveys meaning.
semicircular canals  The curved vestibular organs of the inner ear that detect rotary movements of the head in any direction.
sensation  The process that detects stimuli from the body or surroundings.
sensation seeking  The extent to which an individual seeks sensory stimulation.
sensorimotor stage  The Piagetian stage, from birth through the second year, during which the infant learns to coordinate sensory experiences and motor behaviors.
sensory adaptation  The tendency of the sensory receptors to respond less and less to a constant stimulus.
sensory memory  The stage of memory that briefly, for at most a few seconds, stores exact replicas of sensations.
sensory neuron  A neuron that sends messages from sensory receptors to the central nervous system.
sensory receptors  Specialized cells that detect stimuli and convert their energy into neural impulses.
sensory transduction  The process by which sensory receptors convert stimuli into neural impulses.
serial-position effect  The superiority of immediate recall for items at the beginning and end of a list.
set point  A specific body weight that the brain tries to maintain through the regulation of diet, activity, and metabolism.
sex-linked traits  Traits controlled by genes located on the sex chromosomes.
sexual orientation  A person's pattern of erotic attraction to persons of the same sex, opposite sex, or both sexes.
sexual response cycle  During sexual activity, the phases of excitement, plateau, orgasm, and resolution.
shape constancy  The perceptual process that makes an object appear to maintain its normal shape regardless of the angle from which it is viewed.
shaping  An operant conditioning procedure that involves the positive reinforcement of successive approximations of an initially improbable behavior to eventually bring about that behavior.
short-term memory  The stage of memory that can store a few items of unrehearsed information for up to about 20 seconds.
signal-detection theory  The theory holding that the detection of a stimulus depends on both the intensity of the stimulus and the physical and psychological state of the individual.
single photon emission computed tomography (SPECT)  A brain-imaging technique that creates images of cerebral blood flow.
size constancy  The perceptual process that makes an object appear to remain the same size despite changes in the size of the image it casts on the retina.
skepticism  An attitude that doubts all claims not supported by solid research evidence.
Skinner box  An enclosure that contains a bar or key that can be pressed to obtain food or water, and that is used to study operant conditioning in rats, pigeons, or other small animals.
skin senses  The senses of touch, temperature, and pain.
sleep apnea  A condition in which a person awakens repeatedly in order to breathe.
smooth pursuit movements  Eye movements that track objects.
social attachment  A strong emotional relationship between an infant and a caregiver.
social clock  The typical or expected timing of major life events in a given culture.
social cognition  The process of perceiving, interpreting, and predicting social behavior.
social-comparison theory  The theory that happiness is the result of estimating that one's life circumstances are more favorable than those of others.
social-cultural perspective  The psychological viewpoint that favors the scientific study of human behavior in its social-cultural context.
social facilitation  The improvement in a person's task performance when in the presence of other people.
social learning theory  A theory of learning that assumes that people learn behaviors mainly through observation and mental processing of information.
social loafing  A decrease in the individual effort exerted by group members when working together on a task.
social phobia  A phobia of situations that involve public scrutiny.
social psychology  The field that studies how the actual, imagined, or implied presence of other people affects one another's thoughts, feelings, and behaviors.
social schema  A cognitive structure comprising the presumed characteristics of a role, an event, a person, or a group.
social-skills training  A form of behavioral group therapy that improves the client's social relationships by enhancing her or his interpersonal skills.
social support  The availability of support from other people, whether tangible or intangible.
sociobiology  The study of the hereditary basis of human and animal social behavior.
soma  The cell body, the neuron's control center.
somatic nervous system  The division of the peripheral nervous system that sends messages from the sensory organs to the central nervous system and messages from the central nervous system to the skeletal muscles.
somatosensory cortex  The area of the parietal lobes that processes information from sensory receptors in the skin.
sound localization  The process by which the individual determines the location of a sound.
specific phobia  An anxiety disorder marked by an intense, irrational fear of a specific object or situation.
spermarche  The first ejaculation, usually occurring between the ages of 13 and 15.
spinal cord  The structure of the central nervous system that is located in the spine and plays a role in bodily reflexes and in communicating information between the brain and the peripheral nervous system.
split-brain research  Research on hemispheric specialization that studies individuals in whom the corpus callosum has been severed.
spontaneous recovery  

1. In classical conditioning, the reappearance after a period of time of a conditioned response that has been subjected to extinction.

2. In operant conditioning, the reappearance after a period of time of a behavior that has been subjected to extinction.


spontaneous remission  The improvement of some persons with psychological disorders without their undergoing formal therapy.
sport psychology  The field that applies psychological principles to help amateur and professional athletes improve their performance.
SQ3R method  A study technique in which the student surveys, questions, reads, recites, and reviews course material.
standard deviation  A statistic representing the degree of dispersion of a set of scores around their mean.
standardization  1. A procedure assuring that a test is administered and scored in a consistent manner. 2. A procedure for establishing test norms by giving a test to large samples of people who are representative of those for whom the test is designed.
state-dependent memory  The tendency for recall to be best when one's emotional or physiological state is the same during the recall of a memory as it was during the encoding of that memory.
statistical significance  A low probability (usually less than 5 percent) that the results of a research study are due to chance factors rather than to the independent variable.
statistics  Mathematical techniques used to summarize research data or to determine whether the data support the researcher's hypothesis.
stereotype  A social schema that incorporates characteristics, which can be positive or negative, supposedly shared by almost all members of a group.
stimulants  Psychoactive drugs that increase central nervous system activity.
stimulus discrimination  In classical conditioning, giving a conditioned response to the conditioned stimulus but not to stimuli similar to it.
stimulus generalization  In classical conditioning, giving a conditioned response to stimuli similar to the conditioned stimulus.
storage  The retention of information in memory.
stress  The physiological response of the body to physical and psychological demands.
stressor  A physical or psychological demand that induces physiological adjustment.
structuralism  The early school of psychology that sought to identify the components of the conscious mind.
sublimation  In psychoanalytic theory, the defense mechanism that involves expressing sexual or aggressive impulses through indirect, socially acceptable outlets.
subliminal perception  The unconscious perception of stimuli that are too weak to exceed the absolute threshold for detection.
subliminal psychodynamic activation  The use of subliminal messages to stimulate unconscious fantasies.
superconducting quantum interference device (SQUID)  A brain-imaging technique that uses changes in magnetic fields to trace pathways of brain activity associated with processes such as hearing or movement.
superego  In Freud's theory, the part of the personality that acts as a moral guide telling us what we should and should not do.
surface structure  The word arrangements used to express thoughts.
survey  A set of questions related to a particular topic of interest administered to a sample of people through an interview or questionnaire.
sympathetic nervous system  The division of the autonomic nervous system that arouses the body to prepare it for action.
synapse  The junction between a neuron and a gland, muscle, sensory organ, or another neuron.
synaptic transmission  The conveying of a neural impulse between a neuron and a gland, muscle, sensory organ, or another neuron.
synesthesia  The process in which an individual experiences sensations in one sensory modality that are characteristic of another.
syntax  The rules that govern the acceptable arrangement of words in phrases and sentences.
systematic desensitization  A form of counterconditioning that trains the client to maintain a state of relaxation in the presence of imagined anxiety-inducing stimuli.
taste buds  Structures lining the grooves of the tongue that contain the taste receptor cells.
telegraphic speech  Speech marked by reliance on nouns and verbs, while omitting other parts of speech, including articles and prepositions.
temperament  A person's characteristic emotional state, first apparent in early infancy and possibly inborn.
temporal lobe  A lobe of the cerebral cortex responsible for processing hearing.
teratogen  A noxious substance, such as a virus or drug, that can cause prenatal defects.
test  A statistical technique used to determine whether the difference between two sets of scores is statistically significant.
testes  The male gonads, which secrete hormones that regulate the development of the male reproductive system and secondary sex characteristics.
thalamus  A brain stem structure that acts as a sensory relay station for taste, body, visual, and auditory sensations.
theory  An integrated set of statements that summarizes and explains research findings, and from which research hypotheses can be derived.
theory of multiple intelligences  Howard Gardner's theory of intelligence, which assumes that the brain has evolved separate systems for seven kinds of intelligence.
thinking  The mental manipulation of words and images, as in concept formation, problem solving, and decision making.
timbre  The subjective experience that identifies a particular sound and corresponds most closely to the mixture of sound waves composing it.
tip-of-the-tongue phenomenon  The inability to recall information that one knows has been stored in long-term memory.
token economy  An operant conditioning procedure that uses tokens as positive reinforcers in programs designed to promote desirable behaviors, with the tokens later used to purchase desired items or privileges.
trait  A relatively enduring, cross-situationally consistent personality characteristic that is inferred from a person's behavior.
transactional analysis (TA)  A form of psychoanalytic group therapy, developed by Eric Berne, that helps clients change their immature or inappropriate ways of relating to other people.
transcutaneous electrical nerve stimulation (TENS)  The use of electrical stimulation of sites on the body to provide pain relief, apparently by stimulating the release of endorphins.
transformational grammar  The rules by which languages generate surface structures from deep structures, and deep structures from surface structures.
transitive inference  The application of previously learned relationships to infer new relationships.
trephining  An ancient technique in which sharp stones were used to chip holes in the skull, possibly to let out evil spirits that supposedly caused abnormal behavior.
trial and error  An approach to problem solving in which the individual tries one possible solution after another until one works.
triarchic theory of intelligence  Robert Sternberg's theory of intelligence, which assumes that there are three main kinds of intelligence: componential, experiential, and contextual.
trichromatic theory  The theory that color vision depends on the relative degree of stimulation of red, green, and blue receptors.
trust versus mistrust  Erikson's developmental stage in which success is achieved by having a secure social attachment with a caregiver.
two-factor theory  The theory that emotional experience is the outcome of physiological arousal and the attribution of a cause for that arousal.
tympanic membrane  The eardrum; a membrane separating the outer from the middle ear that vibrates in response to sound waves that strike it.
Type A behavior  A syndrome --marked by impatience, hostility, and extreme competitiveness-- that is associated with the development of coronary heart disease.
unconditioned response (UCR)  In classical conditioning, an unlearned, automatic response to a particular unconditioned stimulus.
unconditioned stimulus (UCS)  In classical conditioning, a stimulus that automatically elicits a particular unconditioned response.
unconscious mind  The level of consciousness that contains thoughts, feelings, and memories that influence us without our awareness and that we cannot become aware of at will.
underextension  The tendency to apply a word to fewer objects or actions than it actually represents.
unilateral neglect  A disorder, caused by damage to a parietal lobe, in which the individual acts as though the side of her or his world opposite to the damaged lobe does not exist.
validity  The extent to which a test measures what it is supposed to measure.
variability hypothesis  The theory that men, as a group, are more variable than women.
variable  An event, behavior, condition, or characteristic that has two or more values.
variable-interval schedule of reinforcement  A partial schedule of reinforcement that provides reinforcement for the first desired response made after varying, unpredictable lengths of time.
variable-ratio schedule of reinforcement  A partial schedule of reinforcement that provides reinforcement after varying, unpredictable numbers of desired responses.
variance  A measure based on the average deviation of a set of scores from their group mean.
vestibular sense  The sense that provides information about the head's position in space and helps in the maintenance of balance.
visible spectrum  The portion of the electromagnetic spectrum that we commonly call light.
vision  The sense that detects objects by the light reflected from them into the eyes.
visual agnosia  A condition in which an individual can see objects and identify their features but cannot recognize the objects.
visual cortex  The area of the occipital lobes that processes visual input.
visual illusion  A misperception of physical reality usually caused by the misapplication of visual cues.
volley theory  The theory of pitch perception that assumes that sound waves of particular frequencies induce auditory neurons to fire in volleys, with one volley following another.
Wada test  A technique in which a cerebral hemisphere is anesthetized to assess hemispheric specialization.
Weber's law  The principle that the amount of change in stimulation needed to produce a just noticeable difference is a constant proportion of the original stimulus.
Wernicke's area  The region of the temporal lobe that controls the meaningfulness of speech.
Yerkes-Dodson law  The principle that the relationship between arousal and performance is best represented by an inverted U-shaped curve.