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 Glossary 1

Glossary Of Terms A-L For Introduction to Psychology

Glossary 2 M -Z

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Abnormal - Term used to describe behavior that is rare or dysfunctional, causes personal distress, or deviates from social norms

absolute threshold - Minimum amount of energy required for conscious detection of a stimulus 50 percent of the time by the individuals tested

acquired immunodeficiency syndrome (AIDS) - Viral disease transmitted via bodily fluids such as blood and semen usually during sexual relations or by sharing needles used by a person infected with the human immunodeficiency virus (HIV); the virus attacks the body's immune system, resulting in vulnerability to infections and diseases, which eventually cause death

action potential - Reversal in electrical charge of a neuron that occurs when the neuron fires

activation-synthesis hypothesis - Explanation of dreams that suggests that they result when the cortex seeks to explain the high level of neuronal activity occurring during REM sleep

adaptation - Loss of sensitivity to a stimulus by the receptors as a result of continued presentation of that stimulus

adolescence - The years between approximately age 12 and age 20

adrenogenital syndrome - Condition caused by exposure to excessive amounts of androgens during the fetal period; can result in a genetic female with genitals resembling those of males

afferent (sensory) nerves - Nerves that carry information from the receptors to the brain and spinalcord

ageism - Viewing elderly people in a negative manner

aggression - Physical or psychological behavior that is performed with the intent of doing harm

Agonist - Drug that enhances the operation of a neurotransmitter

Agoraphobia - Avoidance of public places or situations in which escape may be difficult should the individual develop incapacitating or embarrassing symptoms of panic

Alcohol - Depressant psychoactive substance, also known as ethyl alcohol or ethanol

Algorithm - Systematic procedure for solving a problem by evaluating all possible solutions until the correct one is found

altered state of consciousness - State of consciousness that is different than normal waking consciousness

altruism - Helping behavior performed voluntarily with no anticipation of reward

Alzheimer's disease - Degenerative brain disorder that results in progressive loss of intelligence and awareness

American Sign Language (ASL) - manual language used for communication by the deaf

Amnesia - Loss of memory that occurs as a result of physical or psychological trauma

Amniocentesis - Withdrawal and analysis of amniotic fluid to detect genetic abnormalities in the fetus

Amphetamines - Stimulants that have been used to reduce appetite and treat attention deficit hyperactivity disorder and narcolepsy

Amplitude - Strength or intensity of a stimulus

anal stage - Second stage of psychosexual development, during which the focus of pleasure is the anus and conflict often occurs as efforts are made to toilet-train the child

androgen insensitivity syndrome - Failure by a male embryo to respond to male hormones

androgens - General name given to the sex hormones that predominate in males

anomalous trichromat - Person with a form of colorblindness in which one of the three primary colors (red, blue, or green) is processed incorrectly

anorexia nervosa - A potentially life-threatening eating disorder occurring primarily in adolescent and young adult females; an intense fear of becoming fat leads to self-starvation and weight loss; accompanied by a strong belief that one is fat despite objective evidence to the contrary

anoxia - Reduction or lack of oxygen

antagonist - Drug that blocks the operation of a neurotransmitter

anterograde amnesia - Inability to store new memories following a traumatic event

antianxiety drugs - Minor tranquilizers used to reduce anxiety

antigens - Foreign substances such as bacteria that trigger an immune response

antipsychotic drugs - Drugs that reduce the symptoms of schizophrenia by blocking dopamine receptors in the brain

antisocial personality disorder - Personality disorder characterized by deceitful, impulsive, reckless actions for which the individual feels no remorse

anxiety - General feeling of apprehension characterized by behavioral, cognitive, or physiological symptoms

aphasia - Loss of the ablity to speak or understand written or spoken language

apparent motion - Illusion of movement in a stationary object

apraxia - Inability to perform previously learned skilled movements

arbitrary inference - Conclusion drawn in the absence of supporting information

assertiveness training - The use of a variety of behavioral techniques, such as modeling and behavioral rehearsal, to help clients develop assertive responses

assimilation - Piaget's term for the process of incorporating information into existing schemas

ataxia - Loss of motor control

attachment - Intense, reciprocal relationship formed by two people, usually a child and an adult

attitudes - Evaluative judgments about objects, people, and thoughts, including affective, knowledge, and behavioral components

attraction - The extent to which we like other people

attribution - The process of assigning causes to events and behaviors

audition - The sense of hearing

autonomic division - Division of the peripheral nervous system involved in the control of bodily functioning

autonomous moral principles - Kohlberg's third stage of moral development (age 13 or later, if at all), in which control over moral conduct is completely internalized

autonomy versus shame and doubt - Erikson's second psychosocial crisis (1 1/2 to 3 years), in which children develop a sense of whether their behavior is under their own control or under the control of external forces

autonomy - The feeling of being able to act independently and having personal control over one's actions

availability heuristic - Heuristic in which the probability of an event is determined by how readily it comes to mind

aversion therapy - Classical conditioning technique for reducing or eliminating behavior by pairing the behavior with an unpleasant (aversive) stimulus

axon - Part of a neuron that transmits information to other neurons and to muscles and glands

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Babinski reflex - Reflex in which the infant's toes fan upward when the bottom of the foot is stroked

backward conditioning - Form of classical conditioning in which the CS comes on after the US has been presented

barbiturates - Depressant drugs that are used to induce sleep but can be deadly when combined with alcohol

Barnum effect - The tendency to accept generalized personality descriptions as accurate descriptions of oneself

basic trust versus basic mistrust - Erikson's first psychosocial crisis (birth to 1 1/2 years), in which children learn through contact with their primary caregiver whether their environment can be trusted

basilar membrane - Membrane located in the cochlea of the inner ear; movement of cochlear fluid causes it to vibrate

behavior genetics - A new field, combining psychology and biology, that studies the influences of heredity and environment on behavior

behavior modification - Using the fundamental principles of learning to change inappropriate behaviors

behavioral model - The view that psychological disorders are learned behaviors that follow the principles of classical and operant conditioning or modeling

behavioral perspective - Perspective that focuses on observable behavior and emphasizes the learned nature of behavior

bereavement - Emotional and role changes that follow death

bias - Beliefs that interfere with objectivity

binocular cues - Cues for depth perception that involve the use of both eyes

binocular disparity - The difference between the images seen by the two eyes

biofeedback - Providing information about some ongoing biological process such as muscle tension in the hope that a person will learn to adjust the process

biomedical therapies - A set of treatments for mental illness that include drugs, psychosurgery, and electroconvulsive therapy

bipolar cells -  Cells in the retina that connect the receptors to ganglion cells

bipolar disorder - Mood disorder in which the individual experiences episodes of mania and depression, which usually alternate

blind spot - Location at which the optic nerve leaves the eyeball; contains no receptors

blocking - Situation in which the conditionability of a CS is weakened when it is paired with a US that has previously been paired with another CS

brain asymmetries - Differences between the two hemispheres of the brain

brainstorming - Free expression of ideas by members of a group to solve a problem

bulimia nervosa - Eating disorder in which a victim alternately consumes large amounts of food (gorging) and then empties the stomach (purging), usually by inducing vomiting

burnout - Emotional and physical exhaustion that interferes with job performance

bystander effect - The tendency for a group of bystanders to be less likely than an individual to provide assistance to a person in trouble

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Cannon-Bard theory - Theory that the thalamus relays information simultaneously to the cortex and to the sympathetic nervous system, causing emotional feelings and physiological changes to occur at the same time

Case study - In-depth study of a single individual that can often provide suggestions for further research

Cataracts - Clouding of the lens of the eye

central deafness -Deafness resulting from damage to the auditory pathways or auditory cortex of the brain.

central nervous system (CNS) - Division of the nervous system that consists of the brain and spinal cord

cerebellum - Structure of the hindbrain that coordinates muscular movements

cesarean section - Procedure in which a baby is surgically removed from the uterus

chromosomes - Segments of genetic material located in the nucleus of each cell; human cells have 23 pairs of chromosomes, one of each pair being inherited from each parent

circadian rhythm -Internal biological changes that occur on a daily schedule

classical conditioning - Learning that occurs when two stimuli, a conditioned stimulus and an unconditioned stimulus, are paired and become associated with each other

client-centered therapy - Therapy designed to create an environment in which the client is able to find solutions to his or her problems

clinical psychology - Specialty of psychology that involves the diagnosis and treatment of psychological disorders

closure - Gestalt principle stating that organizing perceptions into whole objects is easier than perceiving separate parts independently

coactors - Other people who are present and are engaging in the same behaviors as an individual at the same time

cognitive development - Changes that occur in our thought processes throughout life

cognitive developmental theory - Explanation for the learning of gender roles that holds that cognitive factors give rise to gender identity, gender stability, and gender constancy

cognitive dissonance - Aversive state produced when an individual has two incompatible thoughts or cognitions simultaneously

cognitive model - A view that emphasizes thinking as the key element in causing psychological disorders

cognitive perspective - View that focuses on the study of how thought occurs, memory processes, and how information is organized and stored

cognitive psychology - Study of higher mental processes, such as thinking, knowing, and deciding

cognitive therapies - Therapies designed to change cognitions in order to eliminate maladaptive behaviors

cohort - Group of individuals born in the same period

collectivism - Placing group goals above individual goals

color afterimage - Perception of a color that is not really present; occurs after viewing the opposite or complementary color

commonsense view of emotions - View that emotions precede and cause bodily changes

companionate love - Long-lasting form of love that involves commitment

comparison level - General outcome expected from a particular relationship

compliance - Initiating or changing a behavior in response to a request

computerized axial tomography (CT or CAT) - Imaging technique that involves the production of a large number of X-rays interpreted by a computer

concepts - Mental categories that share common characteristics

concordance rate - Percentage of twin pairs in which both twins have a disorder that is of interest to an investigator

concrete operational stage - Piaget's third stage of cognitive development, in which the child is able to use mental representations to think about current objects and events but is not yet capable of abstract thought

conditioned response (CR) - Response elicited by a conditioned stimulus that has been paired with an unconditioned stimulus. It is similar to the unconditioned response

conditioned stimulus (CS) - Neutral stimulus that acquires the ability to elicit a conditioned response after being paired with an unconditioned stimulus

conduction deafness - Deafness due to problems associated with transmitting sounds through the outer and middle ear

cones - Visual receptors that are less prevalent than rods, have a higher threshold and higher acuity, and are able to detect color

confirmation bias - Committing to one hypothesis without adequately testing other possibilities

conflict - A state that occurs when an individual must chose between two or more competing goals

conformity - Initiating or changing a behavior in response to indirect social pressures

conjunctive eye movements - Movements of the eyes in the same direction

consciousness - A person's awareness of feelings, sensations, and thoughts at a given moment

conservation - Recognition that a physical change in a substance does not change the amount of that substance

consolidation hypothesis - Hypothesis that memories must be consolidated or "set" before they can be stored in LTM

consumer psychology - Specialty of psychology that studies consumers and the choices they make

continuous reinforcement - Reinforcement that follows every target response

control group - A comparison group in an experiment that does not receive the effect of the independent variable being manipulated

conventional role conformity - Kohlberg's second stage of moral development (ages 10 to 13), in which rules and standards are internalized and behaviors are performed in order to please others

conversion disorder - Somatoform disorder in which an individual presents sensory or motor symptoms that do not have a medical explanation

coping - Cognitive and behavioral efforts that are used to reduce the effects of stress

corpus callosum - Wide band of neural fibers that connects the two hemispheres of the brain

correlation coefficient - Number ranging between +1.00 and -1.00 that represents the degree of relationship between two variables

counseling psychology - Specialty of psychology that deals with less serious problems than those treated by clinical psychologists

creativity - The ability to produce work that is both novel and appropriate

critical period - A specific time during development when damage may occur or certain processes should take place

cross-sectional study -Research technique in which participants, often of different ages, are tested or observed during a limited time span or only once

crystallized intelligence - Intelligence that involves the ability to retrieve and use information that has been learned and stored

cumulative record - Results of a series of operant conditioning trials, shown as rate of responding

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daydreaming - A form of consciousness that involves fantasies, usually spontaneous, that occur while a person is awake

debriefing - Providing a complete explanation of research that has involved deception

decibel (db) - Unit of measure of the amount of energy producing the vibrations we perceive as sound

defense mechanism - Psychodynamic term used to describe primarily unconscious methods of reducing anxiety or guilt that results from conflicts among the id, ego, and superego

deindividuation - Phenomenon in which the presence of a group results in a loss of personal identity and a decrease in responsibility

deinstitutionalization - The policy of discharging mentally ill patients from institutions on the assumption that they can be cared for in their communities

delayed conditioning - Form of classical conditioning in which the CS comes on and stays on for a period of time before the US is presented

delusion - An obviously false belief that is difficult to change

dementia - General intellectual decline associated with old age; may be reversible when caused by medication or blood clots

dendrite - Part of a neuron that receives information from receptors and other neurons

deoxyribonucleic acid (DNA) - Chemical name for the genetic material located in the nucleus of each cell

dependent variable - Variable that shows the outcome of an experiment by revealing the effects of an independent variable

depolarization - Process in which the electrical charge of the neuron becomes less negative

depressants - Drugs that slow the activity of the central nervous system

depression - Mood disorder characterized by sadness; feelings of guilt; changes in sleep, appetite, and motor behavior; and sometimes thoughts of suicide

depth perception - The ability to perceive our world three dimensionally

developmental psychology - Study of physical and cognitive changes throughout the life span, from conception until death

diagnosis - The process of deciding whether a person has symptoms that meet established criteria of an existing classification system

dichromat - Individual who has trouble seeing one of the primary colors (red, blue, or green) due to a form of colorblindness

differential threshold - Smallest amount of stimulation that must be added to or subtracted from an existing stimulus for a person to be able to detect a change 50 percent of the time

discrimination - Behaviors that adversely affect members of a particular group

discriminative stimulus - Stimulus or signal telling the participant that responding will be reinforced

display rules - Culturally specific rules for which emotions to display, to whom, and when they can be displayed

dissociation - Splitting of conscious awareness that is believed to play a role in hypnotic pain reduction

dissociative amnesia - Dissociative disorder that involves a sudden inability to recall important personal information; often occurs in response to trauma or extreme stress

dissociative disorders - Disorders affecting a function of the mind, such as memory for events, knowledge of one's identity, or consciousness

dissociative fugue - Dissociative disorder involving amnesia and flight from the workplace or home; may involve establishing a new identity in a new location

dissociative identity disorder (multiple personality) - Dissociative disorder in which a person has two or more separate personalities, which usually alternate

divided attention - The ability to process more than one source of stimulation at the same time

dream - A succession of visual images experienced during sleep

dysfunctional - Term used to describe behaviors that adversely affect an individual's functioning

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early adulthood - Period from approximately age 20 to age 40

eclectic approach - View of psychology that combines several different approaches

efferent (motor) nerves - Nerves that carry information from the brain and spinal cord to the muscles

ego - In psychodynamic theory, the element of the mind that operates according to the reality principle and serves to satisfy the id and the superego

egocentrism - Inability to see a situation or event from another person's point of view

elaborative rehearsal - Rehearsal in which meaning is added to the material to be remembered

Electra complex - Process that occurs during the phallic stage in which a girl wishes to possess her father sexually

electroconvulsive therapy (ECT) - A biomedical treatment in which an electric current is passed through the brain to induce a seizure; most often used to treat severe depression

electroencephalograph (EEG) - Device that monitors and records electrical activity of the brain

embryo - A developing organism during the stage when the major organ systems are formed

emotions - Physiological changes and conscious feelings of pleasantness or unpleasantness, aroused by external and internal stimuli, that lead to behavioral reactions

empty nest syndrome - Period of adjustment for parents after all children have left home

encoding specificity - Theory stating that the effectiveness of memory retrieval is directly related to the similarity of the cues present when the memory was encoded and when the memory is retrieved

encoding - First stage of the memory process, in which information is transformed or coded (a transduction process) into a form that can be processed further and stored

endocrine system - System of glands that produce and secrete chemicals

endorphins - Opiatelike substances produced by the body that block pain by inhibiting the release of substance P

enuresis - Bedwetting, a sleep disorder that occurs primarily in children

epidemiologist - Scientist who studies the distribution and causes of accidents, diseases, and psychological disorders in a given population

episodic memory - Memory of one's own personal experiences

estrogens - General name given to the sex hormones that predominate in females

ethnocentrism - Belief that one's own country or culture is superior to all other countries and cultures

evolutionary perspective - Interest in the role a physiological structure or behavior plays in helping the organism adapt to the environment

experimental group - The group in an experiment that receives the effect of the independent variable being manipulated

experimental method - Research method that involves manipulating independent variables to determine how they affect dependent variables

extinction - The process of removing reinforcers, which leads to a decrease in the strength of a CR

extracellular fluids - Fluids such as blood, water, and cerebrospinal fluid that are found outside the cells of the body

extraneous variables - Variables, other that the independent variable, that can influence the outcome of an experiment

extrasensory perception (ESP) - Occurrence of behaviors or experiences that cannot be explained by information received by the senses

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facial feedback hypothesis - Hypothesis that making a certain facial expression will produce the corresponding emotion

feature analysis theory - Theory of pattern perception stating that we perceive basic elements of an object and assemble them mentally to create the complete object

fetal alcohol syndrome (FAS) - Condition found in some children born to alcoholic mothers, characterized by lower birth weight, small head circumference, and mental retardation

fetishism - Paraphilia involving sexual arousal by unusual objects or body parts

fetus - The developing baby from about the ninth week after conception until birth

figure-ground relationship - Organization of perceptual elements into a figure (the focus of attention) and a background

fixation - Cessation of further development, resulting in behaviors that are characteristic of the stage of development in which the fixation occurred

flashbulb memory - Very detailed memory of an arousing, surprising, or emotional situation

fluid intelligence - Intelligence involving the ability to see new relationships, solve new problems, form new concepts, and use new information

foot-in-the-door effect - Phenomenon in which a person who has agreed to a small request is more likely to comply with a subsequent larger request

forebrain - Major division of the brain that consists of subcortical structures and the cerebral cortex

foreclosure - Uncritical acceptance of parental values and desires; hampers the development of a unique identity

forensic psychology - Application of psychology to law and legal proceedings

formal operational stage - Final stage of intellectual development, characterized by abstract thinking; achieved during adolescence or adulthood

fovea - Indented spot in the center of the retina that contains only cones

fraternal twins - Twins who develop from two ova fertilized by two different sperm; genetically related as siblings

free association - A psychoanalytic technique in which the patient is asked to say whatever comes to mind without censoring anything

free recall - Learning procedure in which material that has been learned may be repeated in any order

frequency theory - Theory stating that the basilar membrane vibrates at different rates to create the perception of different pitches

friendship - Form of interpersonal attraction that is governed by an implicit set of rules

frustration-aggression hypothesis - The hypothesis that aggression is likely to occur when a person is frustrated

functional fixedness - Inability to see new uses for familiar objects

functionalism - Approach to psychology that focused on the functions of consciousness

fundamental attribution error - The tendency to attribute behaviors to internal causes

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ganglion cells - Cells in the retina whose axons form the optic nerve

gate control theory - Theory of pain stating that the release of substance P in the spinal cord produces the sensation of pain

gender identity disorder - Sexual disorder characterized by a person's belief that he or she was born with the wrong biological sex organs

gender roles - Behaviors considered appropriate for males and females in a given culture

gender-schema theory - Explanation for the learning of gender roles that suggests that children form schemas of masculine and feminine attributes, which influence memory, perception, and behaviors

gender - Social and psychological phenomena associated with being "feminine" or "masculine" as these concepts are defined in a given culture

general adaptation syndrome (GAS) - Typical series of responses to stressful situations that includes the alarm, resistance, and exhaustion stages

generalization - Occurrence of responses to stimuli that are similar to a CS

generalized anxiety disorder - Chronically high level of anxiety that is not attached to a specific stimulus

generativity versus stagnation - Erikson's seventh psychosocial crisis, which occurs during middle adulthood and reflects concern, or lack of concern, for the next generation

genes - Units of hereditary material that line the chromosomes and provide information concerning the form and function of each cell

genital stage - Stage of psychosexual development that begins at puberty and usually leads to normal adult sexual development

Gestalt psychology - Approach to psychology most noted for emphasizing that our perception of a whole is different from our perception of the individual stimuli

Gestalt therapy - A humanistic form of therapy developed by Fritz Perls in which therapists may frustrate and challenge clients to help them toward self-acceptance

glia cell - Type of cell found in the nervous system that forms the myelin sheath

glucostatic theory - Theory of short-term hunger regulation that stresses the importance of the level of usable blood sugar (glucose)

good continuation and direction - Gestalt principle stating that smooth, flowing figures are more readily perceived than choppy, broken figures

grasp reflex - Reflex consisting of a very strong hold on any object placed in the palm

group polarization - Phenomenon in which group decision making enhances or amplifies the original opinions of the group's members

group therapy - Therapy in which clients discuss problems in groups that may include individuals with similar problems

groupthink - The tendency to make decisions intended primarily to promote the harmony of the group

gustation - The sense of taste

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habituation - Decrease in response strength that occurs as a function of repeated stimulation

hallucinations - Sensory experiences that are not caused by stimulation of the relevant sensory organ

hallucinogen - Drugs that can cause changes in perceptions such as hallucinations

hardiness - A psychological characteristic that can reduce the impact of stressors, consisting of commitment, belief in a sense of control, and viewing change as a challenge

health psychology - Subfield of psychology that is concerned with how psychological and social variables affect health and illness

heritability - Percentage of differences among a group of people in a characteristic, such as intelligence, that is believed to be due to inherited factors

hermaphrodite - Individual who has both ovarian and testicular tissue

hertz (Hz) - Unit of measure (in cycles per second) of the frequency of a sound wave

heuristics - Educational guesses or rules of thumb for solving problems

hindbrain - Oldest of the three main divisions of the brain; its major structures are the medulla, pons, and cerebellum

homeostasis - Tendency of the body to maintain an optimum range of physiological processes

hormones - Chemicals produced by the glands of the endocrine system that are carried by the bloodstream to other organs

hospice - Institution where terminally ill patients and their families are given warm, friendly, personalized care

hostile aggression - Aggressive behavior that is performed with the specific intent of harming another person

human immunodeficiency virus (HIV) - A virus that is usually contracted through the transfer of semen, blood, or vaginal secretions and is the cause of AIDS

humanistic perspective - Approach to psychology associated with Abraham Maslow and Carl Rogers; emphasizes free will and individuals' control of their behavior

humanistic psychology - General approach to psychology, associated with Abraham Maslow and Carl Rogers, that emphasizes individuals' control of their own behavior

humanistic therapies - Therapies that emphasize the present and the ability of clients to solve their own problems when they are able to accept themselves

hyperpolarization - Process in which the electrical charge of the neuron becomes more negative

hypersomnias - Sleep disorders characterized by excessive daytime sleepiness despite a normal amount of sleep at night

hypnosis - State of heightened susceptibility to suggestions

hypochondriasis - Somatoform disorder in which a person believes that he or she has a serious disease despite repeated medical findings to the contrary

hypothesis - Prediction about future behaviors that is derived from observation and theories

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id - In psychodynamic theory, the most basic element of the personality; it is the source of the instincts and operates on the pleasure principle

identical twins - Twins who develop from one ovum fertilized by one sperm; genetically identical to each other

identity diffusion - Failure to develop an identity because of lack of goals and general apathy

identity versus identity confusion - Erikson's fifth psychosocial crisis, in which the adolescent faces the task of determining his or her identity and role in society

imagery - Process of visualizing items as they are being learned

imaginary audience - Adolescent's assumption that everyone else is concerned with his or her appearance and behavior

immune system - System that protects the body against foreign substances such as viruses and bacteria

impression formation - The process of forming an opinion about another person

incidence - Number or percentage of newly diagnosed cases of a particular disorder in a given population

inclusiveness - Gestalt principle stating that the identity of a smaller figure may be lost within a larger, more complex figure

independent variable - Variable manipulated by a researcher to determine its effects on a dependent variable

individualism - Placing one’s own goals above those of the group

industrial and organizational (I/O) psychology - Application of psychology to problems of businesses and other organizations

industry versus inferiority - Erikson's fourth psychosocial crisis, in which children begin to acquire the knowledge and skills that will enable them to become productive members of society

informed consent - Written document in which a potential subject agrees to participate in a research study after receiving information about the researcher's specific procedures

initiative versus guilt - Erikson's third psychosocial crisis, in which children begin to evaluate the consequences of their behavior

insanity - Legal ruling that a person accused of a crime is not held legally responsible for that act; defined in most states as the inability to tell the difference between right and wrong at the time the crime is committed

insight learning - Sudden grasp of a concept or the solution to a problem; typically characterized by an immediate change in behavior

insomnia - Complaints of difficulty falling asleep, staying asleep, frequent awakenings, or poor-quality sleep

instrumental aggression - Aggression that causes harm in the process of achieving another goal

integrity versus despair - Erikson's eighth psychosocial crisis, which occurs during late adulthood; integrity reflects a feeling that one's life has been worthwhile; despair reflects a desire to relive one's life

intelligence quotient (IQ) - Score that indicates how an individual compares to others on an intelligence test

intelligence - The ability to excel at a variety of tasks, especially those related to academic success

interdependence theory - Theory of interpersonal relationships that stresses the costs and rewards involved

intermittent, or partial, reinforcement - Reinforcement that does not follow every target response

interval schedule - Reinforcement schedule that is based on the passage of time and in which a single response at the end of the designated interval is reinforced; intervals may be set (fixed interval, or FI, schedule) or may vary from one reinforcement to the next (variable-interval, or VI, schedule).

intimacy versus isolation - Erikson's sixth psychosocial crisis, in which the young adult faces the task of establishing a strong commitment to others (intimacy) or having to deal with isolation

intracellular fluids - Fluids located inside the cells of the body

introspection - Structural psychologists' major method, in which participants reported the contents of their conscious experience

ions - Electrically charged particles

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James-Lange theory - Theory that physiological changes precede and cause emotions

jet lag - Temporary maladjustment that occurs when a change of time zones causes biological rhythms to be out of step with local time

just noticeable difference (jnd) - The smallest difference between two stimuli that is noticeable 50 percent of the time to the individuals tested

kinesthetic sense - System of receptors located in the muscles and joints that provides information about the location of the extremities


latchkey child - Child who is unsupervised after school

late adulthood - Period from approximately age 65 until death

latency stage - Stage of psychosexual development that extends from about age 6 until the onset of puberty and is characterized by low levels of sexual interest

latent content - According to Freud, the real meaning of a dream, connected by symbols to the manifest content

latent learning - Learning that has occurred but is not demonstrated

law of effect - Thorndike's view that reinforcers promote learning, whereas punishers lead to the unlearning of responses

law of parsimony - Principle that simple explanations of phenomena are preferred to complex explanations

learned goals (learned incentives) - Goals or incentives that are learned through the process of classical conditioning

learned helplessness - Belief that one cannot control outcomes through one's actions; usually leads to passivity and reduced motivation and may cause depression

learned motives - Motives that are learned or acquired through the process of classical conditioning

learning - A relatively permanent change in behavior that occurs as a result of experience

levels-of-processing theory - Theory stating that deeper processing of information increases the likelihood that the information will be placed in LTM

Likert scale - Questionnaire that requires individuals to indicate their degree of agreement or disagreement with a set of statements

limbic system - System of interconnected subcortical structures that regulate a variety of motivated behaviors

linguistic relativity hypothesis - Hypothesis that language directs and determines what we think

lipostatic theory - Theory of long-term hunger regulation that stresses the importance of the level of stored body fat

longitudinal study - Research technique in which the same partcipants are tested or observed repeatedly over a period of time

long-term memory (LTM) - Memory stage that has a very large capacity and the capability to store information relatively permanently

long-term potentiation - Condition in which stimulation of the hippocampus results in long-lasting neural activity

lysergic acid diethylamide (LSD) - Powerful hallucinogen derived from the ergot fungus found on rye

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