Glossary of Psychological Terms
Definitions of terms used in psychology, psychometric testing and occupational assessment, organised alphabetically.
CA (Chronological age)
A person's actual age since birth, used alongside mental age (the age level at which a person is performing on a cognitive test) in the traditional formula for computing an IQ score (mental age divided by chronological age, multiplied by 100).
CAI
An abbreviation for computer assisted instruction — see that entry.
California F Scale
A personality measure of traits associated with authoritarianism, developed in the 1940s and comprised of subscales including conventionalism, authoritarian submission and aggression, anti-intraception, superstition and stereotypy, power and toughness, destructiveness and cynicism, projectivity, and preoccupation with sex. Also known simply as the F-Scale, it remains historically significant in social psychology's study of prejudice, even though its methodology has since been criticised.
California Infant Scale
An early measure of infant development, now more commonly known by its later name, the Bayley Scales of Infant Development.
Cannon-Bard theory
A theory of emotion, proposed by Walter Cannon and Philip Bard, holding that emotional experience and physiological arousal occur simultaneously and independently, both triggered by activity in the thalamus, rather than one causing the other. It was developed partly as a challenge to the earlier James-Lange theory, which held that physiological arousal precedes and causes the subjective experience of emotion.
CAT
An abbreviation for the Children's Apperception Test — see that entry.
Catalepsy
A state of muscular rigidity associated with severe psychological disturbance or a hypnotic trance, in which a person's body or limbs, if placed in a particular position, will maintain that position for an unusually long period of time.
Cataplexy
A sudden loss of muscle tone or immobility brought on by strong emotion such as fear, shock or laughter, not to be confused with catalepsy, which is a distinct condition involving sustained rigidity rather than sudden collapse.
Catatonic
Descriptive of a psychotic state generally considered a form of schizophrenia, characterised by dramatic swings in behaviour between rigid, frozen states (including catalepsy) and, at times, extremes of excitement and agitated activity.
Catharsis
An ancient Greek term originally describing the purging of emotion achieved by watching it enacted on stage. In psychotherapy, particularly psychoanalysis, it describes the release of emotional tension that occurs when a conflict is worked through or an insight is achieved; the term is also used more loosely in everyday language to describe any emotional release.
Cathexis
A term used mainly in psychoanalysis for the psychic energy a person invests in another person, place, idea or object. The emotions attached to the object of cathexis may be strongly reactivated whenever that object is encountered again.
Cautious shift
A form of group polarisation in which people arrive at more cautious decisions under the influence of a group than they would individually; the opposite of the risky shift, in which group discussion pushes decisions toward greater risk.
Censorship
In psychoanalysis, the regulatory process by which repressed material in the unconscious is prevented from reaching consciousness if it would be too threatening to the ego. This censorship is thought to relax during sleep, allowing repressed material to surface in disguised form as dreams.
Central nervous system
The part of the nervous system protected by bone — the brain and spinal cord — which integrates sensory information and coordinates the activity of the rest of the body, as distinct from the peripheral nervous system.
Central organising trait
A term from Gordon Allport's trait theory of personality for a trait so pervasive that it is associated with many other traits and behaviours across a person's life — descriptions such as “warm” or “cold” are often cited as examples of such organising traits.
Central tendency
A statistical concept referring to the typical or central value of a set of scores — commonly the mean, median or mode — fundamental to summarising and reporting psychometric test results. See also: bell-shaped curve.
Centring
In Gestalt psychology, a term for the ideal, seamless integration of an organism with its environment, in which perception and action fit together without internal conflict or distortion.
Cephalocaudal
Literally “head to tail”: describes the pattern of physical maturation in humans and animals in which development proceeds from the head downward, with head and upper-body structures maturing before those lower in the body. Compare with proximodistal development, which proceeds from the body's centre outward.
Cerebellum
A structure at the back of the brain, near the top of the spinal cord, primarily involved in maintaining muscle tone and coordinating movement, posture and balance.
Cerebral cortex
The outer layer of grey matter covering most of the brain, thought to be primarily responsible for higher mental processes such as learning, memory, thinking and language.
Cerebral dominance
The tendency for one cerebral hemisphere to be more dominant than the other in regulating certain behaviours — typically the left hemisphere in right-handed people and the right hemisphere in left-handed people, particularly with respect to language function.
Cerebral hemispheres
The two symmetrical halves — left and right — of the cerebrum. The right hemisphere primarily controls the left side of the body and the left hemisphere the right side. See also: split-brain technique, a research method used to study each hemisphere's functions separately.
Cerebrum
The largest and most developed division of the brain in vertebrates, especially in humans, thought to be central to processing sensory information and to all higher-order cognitive activity.
CFF
An abbreviation for critical flicker frequency — see that entry.
Change agent
A person who acts as a catalyst for change in a direction considered desirable — in social psychology, someone who raises the consciousness of a disadvantaged group toward recognising and challenging its own exploitation; in organisational contexts, a manager or external consultant whose role is specifically to design and manage organisational change.
Character armour
A concept from psychoanalyst Wilhelm Reich describing the powerful defensive front an individual builds to protect the ego, coming to dominate the whole personality — for example, disguising underlying hatred as love within a marriage. Reich regarded dismantling this armour as a central task of psychoanalysis. See also: reaction formation.
Character disorder
A behavioural disorder marked by emotional immaturity and a broad inability to cope with the demands of adult life, often expressed through social problems such as substance dependence or criminal behaviour. Some clinicians place antisocial personality within this broader category.
Charcot, Jean Martin (1825-1893)
A French physician and early psychotherapist whose use of hypnosis to probe his patients' underlying problems led him to conclude that neuroses had sexual origins — a conclusion he never made public, out of deference to Victorian sensibilities. One of his students, Sigmund Freud, adopted both his methods and his conclusions, but did make them public, laying groundwork for psychoanalysis.
Charisma
From the Greek word for “gift,” originally referring to a gift of divine grace. An elusive personal quality, often described as personal magnetism, considered by some social scientists an essential ingredient of effective leadership and by others to be largely a matter of perception and social construction rather than an intrinsic trait.
Chi square
A simple, widely used statistical test in psychology and the social sciences for determining whether observed results differ from those expected by chance alone, particularly with categorical data.
Child development
The study of the growing child across physiological, mental, emotional and social dimensions; considered the central concern of developmental psychology.
Child's theory of mind
A phrase describing the mental processes by which children construct their understanding of the world, and of other people's mental states, as they grow. See also: cognitive development.
Childhood
Typically defined, biologically, as the period of human development between birth (or infancy) and puberty, around age 12. Marking this period off from others, and expecting distinct behaviour during it, gives childhood a particular psychological significance beyond biology alone — it is not a fixed, universal phenomenon, varying considerably across cultures and historical periods, and in some societies barely existing as a distinct category. See also: ageism.
Childhood amnesia
The near-universal inability of adults to recall specific autobiographical memories from early childhood, typically before around age three to four; also called infantile amnesia.
Children's Apperception Test
A version of the Thematic Apperception Test, adapted with child-friendly imagery (often animal figures) for use with children, designed to elicit projective responses revealing underlying attitudes and conflicts.
Choice shift
The American term for group polarisation — the tendency for group discussion to shift individual decisions toward a more extreme position, in either a risky or a cautious direction, than members held before deliberating.
Chromosomes
The structures within a cell's nucleus that carry genes, the units of hereditary information passed from parent to offspring.
Chronobiology
The scientific study of biorhythms — the body's internal biological cycles, including the roughly 24-hour circadian rhythm governing sleep, temperature and hormone levels.
Chunking
A memory strategy that groups individual items of information into larger, more meaningful units (“chunks”) to make them easier to retain. Working memory is generally thought to hold around seven, plus or minus two, chunks at a time; increasing how much information fits into each chunk increases the total amount that can be remembered.
Circadian rhythms
From the Latin for “about a day,” these are the biorhythms that operate on a roughly 24-hour cycle, including sleep-wake patterns and fluctuations in body temperature and blood pressure.
Clairvoyance
The purported ability to perceive objects or events without using the ordinary senses — a form of claimed extrasensory perception studied (without reliable scientific support) within parapsychology.
Clang association
A response in a word association test based on the sound of a word rather than its meaning — for example, responding to “master” with “faster.” Clang associations are of particular clinical interest when they appear in disordered speech.
Classical conditioning
A basic form of learning by association, established through the experimental procedures Ivan Pavlov developed in the early twentieth century. It involves repeatedly pairing a conditioned stimulus (such as the sound of a bell) with an unconditioned stimulus (such as food), so that the conditioned stimulus alone eventually elicits a conditioned response (salivation) resembling the original unconditioned response.
Claustrophobia
A phobia involving intense, irrational fear of confined or enclosed spaces.
Clever Hans
The name of a German horse once believed to perform advanced arithmetic. In fact, Hans was responding to subtle, unconscious cues from his trainer signalling when to start and stop pawing the ground. The case became a classic cautionary example in psychology of unintentional experimenter influence on behaviour, and is invoked alongside experimenter bias and the Rosenthal effect whenever apparent animal or human abilities may actually reflect responses to unnoticed cues.
Client
The term used, in place of “patient,” for someone who seeks counselling or psychotherapy from a practitioner working within a humanistic or non-directive approach, emphasising the person's active role in their own treatment.
Client-centred therapy
A form of psychotherapy developed by Carl Rogers, based on unconditional acceptance and regard for the client. Rather than being diagnosed and prescribed treatment, the client is encouraged to draw on their own psychological resources to work through problems as they themselves understand them. See also: non-directive therapy.
Clinical psychologist
A practitioner of clinical psychology, typically holding a doctoral qualification in the field, who may work in hospitals, clinics or private practice, and may also train as a psychoanalyst or other type of psychotherapist.
Clinical psychology
The branch of psychology concerned with applying psychological theory and research to the diagnosis and treatment of emotional, mental and behavioural disorders. Distinguished from psychiatry, which is a medical specialty.
Clustering
A memory strategy closely related to chunking, in which related items are grouped together to aid recall.
CNS
An abbreviation for central nervous system — see that entry.
Co-twin control
An experimental design used with identical twins, in which one twin (the subject) receives a particular treatment or intervention while the other (the control) does not, allowing researchers to study the effects of environment while genetics are held constant.
Coacting group
A sociological term for a set of people who share the same goal but work toward it independently, without communicating or interacting with one another.
Cocktail party phenomenon
The perceptual ability to attend to one conversation among many simultaneous ones — for instance, at a noisy party — while filtering out competing voices and background noise. Widely used as the classic model for studying selective attention in hearing.
Cognition
A broad term covering all the mental processes by which people become aware of, and gain knowledge about, the world — including perception, memory, reasoning and language.
Cognitive development
The way mental structures and processes change over time, increasing in complexity from birth through adulthood; a central concern of Jean Piaget's stage theory of child development.
Cognitive dissonance
A theory of psychological consistency proposed by Leon Festinger, holding that people have a strong drive toward consonance between their beliefs, attitudes and behaviour; when two cognitions conflict, or behaviour clashes with a belief, the resulting tension motivates a person to reduce it — often by changing an attitude rather than admitting inconsistency. A foundational concept in social psychology.
Cognitive ergonomics
The branch of ergonomics concerned with the interaction between people and the computer-based information technology they use, focused on mental workload, usability and error rather than purely physical design.
Cognitive learning theory
A school of thought opposing the strict behaviourist view of a direct stimulus-response link, arguing instead that complex learning involves the active restructuring and reorganising of knowledge by the mind. Contrast with behaviourism.
Cognitive map
A term from learning theorist Edward Tolman for an internal mental representation of how to reach a goal or solve a problem. Tolman's studies of rats in mazes suggested the animals learned an overall spatial map of the maze rather than a fixed sequence of movements.
Cognitive overload
A state in which a person is receiving more information than their mental processing capacity can handle effectively.
Cognitive psychology
The branch of psychology concerned with cognition — particularly perception, learning, memory and thinking — as distinct from behaviourist approaches that avoid reference to internal mental states.
Cognitive revolution
A term for the major shift in psychology, prominent from the 1970s, away from strict behaviourism and toward cognitive psychology's focus on internal mental processes, spurred by developments in computing and information technology and closely tied to the broader emergence of cognitive science.
Cognitive science
The interdisciplinary field studying the mind, drawing together cognitive psychology, artificial intelligence, linguistics, neuroscience and philosophy.
Cognitive therapy
A form of psychotherapy grounded in cognitive psychology, which treats the way people interpret and make sense of their experiences as central to their distress; therapy focuses on identifying unhelpful beliefs and expectations and replacing negative thought patterns with more constructive ones. Often combined with behaviour therapy as cognitive-behavioural therapy (CBT).
Cohort effect
A cohort is a group of people who have lived through the same period and share common historical experiences, most often defined by birth year. Cohorts born decades apart may be shaped in systematically different ways by the prevailing zeitgeist and social conditions of their era, adding depth to findings from both cross-sectional and longitudinal research.
Cold emotion
A psychological state produced by an injection of adrenalin, in which a person experiences the physiological changes typical of emotion — increased heart rate, tension — but reports feeling that an emotion should be occurring without actually experiencing one, illustrating the gap between physiological arousal and subjective emotional experience.
Collective mind
Either (1) the idea that a group possesses mental attributes over and above those of its individual members, or (2) the idea that a group shares common mental processes leading it to take concerted, unified action.
Collective unconscious
A central concept in Carl Jung's analytical psychology, referring to the part of the unconscious shared by all human beings and inherited across generations, containing universal symbols and themes (archetypes). Jung pointed to recurring similarities between dream imagery and mythological symbolism across widely separated cultures as evidence; most psychologists outside the Jungian tradition regard the concept as more mystical than empirical.
Colour blindness
A partial or total inability to distinguish certain colours. Total colour blindness is rare, but partial colour blindness — especially difficulty distinguishing red from green — is relatively common, affecting an estimated 8 to 10 per cent of males (it is much rarer in females, since the relevant genes are X-linked).
Colour constancy
The tendency to perceive an object as having the same colour even as the colour of the light illuminating it changes.
Colour contrast
The perceptual tendency for the difference between two colours to appear intensified when they are placed next to each other.
Colour vision
The process by which the eye discriminates between different wavelengths of light, giving the brain the information it needs to perceive what we experience as distinct colours.
Combat fatigue
An earlier term for the psychological exhaustion and stress reactions of soldiers under prolonged combat conditions; see also: battle fatigue.
Communicator credibility
In social psychology, the degree to which the source of a persuasive message is perceived as believable, generally thought to depend on whether the communicator is seen as both expert and trustworthy.
Community psychology
An approach combining applied clinical and social psychology, aiming to support the wellbeing of psychologically distressed people by intervening in their social environment and drawing on community resources, rather than treating individuals in isolation.
Comparative psychology
The branch of psychology that compares different species, including humans, to understand the similarities and differences in their mental processes and behaviour.
Compensation
A defence mechanism, central to the work of Alfred Adler, in which a person who perceives themselves lacking in some respect tries to make up for it by developing, sometimes to an exaggerated degree, some other characteristic — for example, a person who feels physically small compensating through psychological dominance or aggression. See also: inferiority complex.
Completion test
A type of mental test requiring a respondent to supply a missing letter, word or phrase; first devised by German psychologist Hermann Ebbinghaus in the late nineteenth century.
Complex
In psychoanalysis, a cluster of repressed, emotionally charged ideas that conflict with other, conscious aspects of the personality.
Compliance
In social psychology, a form of yielding to group or authority pressure in which outward behaviour changes without any accompanying change in underlying attitude or belief.
Compulsion
An overwhelming, largely unconscious urge to engage in a behaviour that typically runs contrary to a person's conscious wishes. Compare with obsession, which refers to the intrusive thought rather than the compelled action; the two frequently occur together, as in obsessive-compulsive disorder.
Computer assisted instruction
A method of programmed learning in which a computer functions as a teaching machine, presenting material and adapting to a learner's responses.
Conation
A somewhat old-fashioned term for the general category of mental activity involving impulse, desire, will and striving — sometimes grouped with affect and cognition as a threefold division of psychological life.
Concept formation
A distinctly human mental ability, closely tied to language, that allows people to abstract the essential features of individual objects or experiences and classify them under higher-order categories and rules.
Concrete operations
The third of Jean Piaget's stages of cognitive development, spanning roughly ages 7 to 11, in which children become capable of logical thought about concrete objects and situations, though abstract reasoning remains difficult. Its central achievement is the concept of conservation.
Concrete thinking
Thinking rigidly tied to immediate, tangible experience rather than abstraction, often resulting from brain damage; also used more loosely to describe a person who struggles to see general patterns beyond specific details.
Conditioned response
A response produced solely through the process of conditioning, rather than occurring naturally or automatically. See also: classical conditioning, Pavlov.
Conditioned stimulus
A stimulus that originally has no particular effect on behaviour but, through repeated pairing with an unconditioned stimulus during classical conditioning, comes to reliably elicit a conditioned response.
Conditioning
A process of learning, in humans or animals, in which a given stimulus comes to produce a response other than its normal or automatic one. In Pavlov's classical conditioning, a dog learned to salivate at the sound of a bell, not only at the sight of food; B. F. Skinner later developed operant conditioning, in which the consequences of an animal's own behaviour — reinforcement or punishment — shape increasingly complex behaviour.
Confabulation
The unintentional filling in of memory gaps with plausible but untrue details, without any intent to deceive; occurs in people with memory impairment from brain damage, who typically do not recognise their own confabulated accounts as false.
Confirmation bias
The widespread tendency to notice, seek out, or give greater weight to information that confirms one's existing beliefs, while overlooking or discounting contradictory evidence.
Congenital
Describing a condition or characteristic present at birth, which is not necessarily inherited genetically or innate — it may, for instance, result from factors during pregnancy or birth itself.
Connectionism
A theory within cognitive science, opposed to the older, computer-like information-processing model of the mind, proposing instead that the brain operates as a network capable of performing many operations simultaneously (in parallel) and of learning from experience, unlike the sequential processing of a traditional computer.
Conscious
Being aware of one's environment; in psychoanalysis, specifically those aspects of psychological functioning of which the ego is aware, as distinct from unconscious material.
Consciousness
Awareness of oneself across every aspect of one's existence — thoughts, sensations, environment and identity — one of the most persistently debated concepts in psychology and philosophy of mind.
Consensual validation
Checking one's own perception of something against other people's perceptions, as a way of judging whether what one perceives is accurate or illusory.
Conservation
In Piaget's theory, the key achievement of the concrete operations stage (roughly ages 7 to 11): the understanding that a quantity remains the same (is conserved) even when its outward appearance changes — for example, recognising that the amount of water is unchanged when poured from a tall thin glass into a short wide one.
Consolidation
The idea that after new information is learned, physiological changes occur in the brain over time that help fix it more durably in memory.
Constant object of love
A concept from psychoanalyst Margaret Mahler describing a form of emotional object constancy in which a young child comes to perceive the mother as a stable, constant object of love regardless of momentary absence or frustration.
Construct validity
A measure of how well an item or scale within a psychological test actually assesses the underlying concept, trait or ability it is intended to measure. A core concern in the design of reliable psychometric instruments.
Consumer psychology
The study of people as buyers and users of goods and services. It began in the 1960s with largely psychoanalytic interpretations of product choice, but has since become dominated by cognitive and social psychological approaches, particularly in the study of advertising and marketing effectiveness.
Contagion theory of crowds
A theory in sociology and social psychology, related to the older idea of the group mind, proposing that being part of a crowd assimilates individuals into an overriding psychological unity, altering their usual, individual responses. Compare with: collective mind.
Contamination
In experimental psychology, the distorting effect of factors outside the intended experimental design, most significantly the conscious or unconscious assumptions and expectations of the experimenter. See also: experimenter bias, Rosenthal effect.
Content analysis
A research method for systematically analysing material — text, media, interview transcripts — either to identify categories or themes that emerge from it, or to test a hypothesis against pre-established categories.
Continuity
A principle from Gestalt psychology holding that the brain tends to perceive stimuli that follow each other closely and regularly, in time or space, as belonging together and forming a single, continuous pattern.
Contour
The outline or boundary of an object, considered essential to how it is perceived and distinguished from its background.
Control group
In an experiment, a group of participants as similar as possible to the experimental group, used for comparison. The control group experiences the same conditions as the experimental group except for exposure to the variable under study.
Conventional stage
In Lawrence Kohlberg's theory of moral development, the second of three broad levels, and the one at which most adults' moral reasoning settles. At this stage, people judge right and wrong largely in terms of social approval, conformity and respect for authority, rather than either simple self-interest or independently reasoned universal principles.
Convergent thinking
Thinking that follows conventional, logical lines toward a single best answer to a problem. Contrast with divergent thinking, which generates multiple possible solutions.
Conversion hysteria
A form of hysteria, especially prominent in the early history of psychoanalysis, in which psychological conflict is converted into serious physical symptoms such as paralysis or sensory loss, without an identifiable physical cause. Such dramatic presentations are now rare outside contexts like combat trauma, though related somatising and psychosomatic conditions persist.
Correlation
The statistical relationship, or degree of association, between two variables.
Correlation coefficient
A statistic (commonly denoted r) that measures the strength and direction of the relationship between two variables, ranging from 0 (no relationship) to +1.00 (perfect positive relationship) to –1.00 (perfect negative relationship).
Counter-transference
In psychoanalysis, the analyst's own transference reactions onto the patient; used more broadly to describe any of the analyst's personal feelings, positive or negative, toward the patient during treatment.
Counterculture
A way of life or set of values deliberately opposed to, and distinguished from, the dominant culture of a society.
Cretinism
An older clinical term for the mental and physical developmental impairment caused by untreated thyroid hormone deficiency in early infancy, now generally referred to as congenital hypothyroidism.
Criterion group
A group of people with known characteristics, achievements or behaviours, used as a benchmark against which other individuals' scores on a psychological test are compared and interpreted.
Critical flicker frequency
The frequency at which a flickering light stops appearing to flicker and is instead perceived as a steady, continuous light.
Critical period
A developmental window during which an organism is thought to be optimally receptive to acquiring a particular skill or to certain environmental influences, after which that learning becomes much harder or impossible. See also: imprinting.
Cross-sectional research
A research design that studies a large, diverse group of people at a single point in time, as opposed to following the same people over time. Compare with longitudinal research, and see also: cohort effect.
Crowding behaviour
The study of how animals or humans respond to being in crowded conditions, an area prone to overgeneralisation across species — for instance, treating aggression seen in crowded rats as evidence that human violence in dense urban settings is similarly instinctive. There is little solid evidence that human behaviour in crowded conditions is driven by simple instinct, and such crowding-based explanations for complex social phenomena are generally considered overly simplistic.
Cultural determinism
The view that the dominant influences shaping personality and behaviour patterns are cultural rather than genetically inherited. See also: culture.
Cultural lag
The continued use of outdated practices or ways of doing things even after more effective alternatives are available — a social-level parallel to individual decentring, or difficulty updating one's frame of reference.
Cultural relativism
The view that judgements about different ways of life, or about universal values such as truth, beauty and goodness, cannot be made in absolute terms but only within the context of a particular culture.
Culture
In the anthropological sense, the shared beliefs, values, attitudes and expectations about appropriate behaviour held by members of a social group. To a psychologist, the largely unquestioned assumptions people within a culture hold about the world, human nature, and what counts as right, wrong and normal are often the more psychologically significant layer.
Culture-free tests
Psychological tests designed to eliminate the influence or advantage of particular cultural experience, so that they could, in principle, be administered anywhere with equal validity. Despite this goal, no test yet devised has been shown to be entirely free of cultural influence.
Curiosity
The tendency, seen in humans and many animals, to explore and investigate the environment for its own sake, independent of any specific reward.
Cybernetics
From a Greek term related to “steersman,” cybernetics was introduced in 1948 by engineer Norbert Wiener as the study of regulatory and control mechanisms, such as thermostats, in machines, animals and organisations. It gave rise to the influential analogy of the brain as a computing system and to models of psychological processes as systems of messages governed by feedback.
