Glossary of Psychological Terms
Definitions of terms used in psychology, psychometric testing and occupational assessment, organised alphabetically.
Abnormal
Deviation from statistical, social or ideal norms of behaviour, especially where the deviation causes distress or impairment. From the Latin abnormis, “deviating from a rule.” What counts as abnormal is contested in clinical psychology: some definitions rely on statistical rarity (more than two standard deviations from the mean), others on social judgement, and others on functional impairment. See also: abnormal psychology, deviance, psychopathology.
Abnormal psychology
The branch of psychology concerned with unusual patterns of behaviour, emotion and thought, whether or not they meet the threshold for a diagnosable mental disorder. Historically termed psychopathology. Draws on behavioural, cognitive, biological and psychodynamic models to explain and treat such patterns. See also: clinical psychology, mental disorder.
Adrenalin
Also called epinephrine. A hormone released by the adrenal medulla in response to stress or perceived threat, producing the “fight-or-flight” response: increased heart rate, blood pressure and blood glucose. The name derives from the Latin ad- (“near”) and ren (“kidney”), reflecting the adrenal gland’s location. See also: cortisol, sympathetic nervous system, stress response.
Aesthesiometer
An instrument used to measure tactile sensitivity, typically by determining the minimum distance at which two points of contact on the skin can be perceived as separate (the two-point discrimination threshold). From the Greek aisthesis (“sensation”) and metron (“measure”). Used in early psychophysics by researchers such as Weber and Fechner, and still used in clinical neurology.
Aetiology
Also spelled etiology. The study of causation — in psychology, the biological, psychological and social factors contributing to a disorder or condition. From the Greek aitia (“cause”) and logos (“study of”). Modern clinical practice generally favours a multifactorial or biopsychosocial account of aetiology rather than a single cause. See also: biopsychosocial model.
Affect
The observable expression of a feeling or emotional state — facial expression, tone of voice, gesture — as distinct from the subjective experience of emotion itself or the longer-lasting background state of mood, though the three terms are often used loosely. Clinicians describe affect along dimensions such as flat, blunted, labile or appropriate. From the Latin afficere, “to influence.”
Affiliation
The need or tendency to seek out, form and maintain relationships and group membership. Identified by Henry Murray as one of the psychogenic needs and echoed in Maslow’s need to belong. In organisational psychology, affiliative motivation is studied in relation to teamwork, workplace belonging and retention.
After-image
A visual sensation that persists briefly after the stimulus producing it has been removed — for example, the lingering impression left after staring at a bright light. A classic topic in sensory and perceptual psychology, explained by adaptation in retinal photoreceptors. Afterimages can be positive (same brightness/colour) or negative (reversed).
Age-grading
The process by which a society assigns roles, expectations, rights and responsibilities to individuals according to their age — for instance, distinguishing child, adolescent, adult and elder. Studied within developmental and social psychology and sociology, and closely related to the concepts of age norms and the life-course perspective.
Ageing
The biological, psychological and social process of growing older across the lifespan, encompassing physical change, cognitive change and shifts in social role and status. Studied specifically within gerontology. See also: cognitive ageing, successful ageing.
Ageism
Prejudice or discrimination against individuals or groups on the basis of their age, most commonly directed at older people, expressed through stereotyping, exclusion or unequal treatment. The term was coined by physician Robert Butler in 1969, drawn by analogy with racism and sexism. Relevant to workplace psychology in relation to recruitment and promotion bias.
Alexia
An acquired inability to read, caused by damage to the brain (most often the left hemisphere), as distinct from dyslexia, which is developmental in origin. From the Greek a- (“without”) and lexis (“word, speech”). Subtypes include pure alexia and alexia with agraphia (loss of the ability to write). Studied within neuropsychology.
Anxiety
A term used with many shades of meaning across different areas of psychology. It is generally held to be an unpleasant emotional state resulting from stress or conflict, characterised by fear and apprehension. Where the fear and apprehension are vague, not attached to a specific object, or appear excessive, the anxiety is considered neurotic. Spielberger’s distinction between state anxiety (a temporary response to a situation) and trait anxiety (a stable disposition) is widely used in assessment; persistent, excessive anxiety without a clear external trigger may be diagnosed clinically as generalised anxiety disorder.
Aphasia
A language impairment caused by brain damage — typically stroke or injury to the language areas of the left hemisphere — affecting the production and/or comprehension of speech. Broca’s aphasia (also called expressive aphasia) chiefly affects production; Wernicke’s aphasia (receptive aphasia) chiefly affects comprehension. From the Greek a- (“without”) and phasis (“speech”).
Apollonian
A term describing restraint, rationality, order and moderation, contrasted with the Dionysian (passionate, impulsive, excessive). Originating in Nietzsche’s The Birth of Tragedy, the distinction was later adopted by anthropologist Ruth Benedict to classify cultural patterns of behaviour, and is sometimes applied loosely within personality typologies.
Apparent movement
The perception of motion in a stimulus that is not, in fact, moving — for example, the stroboscopic or phi phenomenon that underlies cinema and sequential flashing lights. A foundational observation in Gestalt psychology, first studied systematically by Max Wertheimer in 1912.
Apperception
The process by which new sensory information is interpreted and given meaning in light of prior knowledge and experience, as distinct from mere perception, which is passive registration of a stimulus. The concept, drawn from Wundt and Herbart, gives its name to the Thematic Apperception Test (TAT), which asks respondents to interpret ambiguous scenes.
Applied psychology
The branch of psychology concerned with applying psychological theory and methods to practical, real-world problems — in organisational, clinical, educational, forensic and sporting settings — as distinct from “pure” or experimental psychology, which is primarily concerned with theory. Industrial-organisational psychology and clinical psychology are both forms of applied psychology.
Appraisal
The process of evaluating the significance of a situation for one’s own wellbeing. Central to Lazarus and Folkman’s cognitive appraisal theory of stress, which distinguishes primary appraisal (is this situation a threat?) from secondary appraisal (do I have the resources to cope with it?). In a workplace context, “appraisal” more commonly refers to formal performance appraisal.
Approach-approach conflict
A decisional conflict arising when a person must choose between two equally attractive or desirable options. One of Kurt Lewin’s three classic types of motivational conflict; typically the easiest to resolve, since either outcome is positive.
Approach-avoidance conflict
A conflict arising when a single goal or object has both attractive and unattractive qualities, producing simultaneous impulses to approach and to avoid it. A Lewinian conflict type associated with ambivalence and vacillating, back-and-forth behaviour as a person nears and then retreats from the goal.
Avoidance
Behaviour aimed at preventing or escaping an aversive stimulus, situation or feeling. Central to learning theory, where avoidance responses are maintained by negative reinforcement (the removal of discomfort), and to clinical models of anxiety disorders, in which avoidance temporarily reduces fear but prevents the extinction of that fear over time.
Avoidance-avoidance conflict
A conflict between two equally undesirable options, where both must be avoided but a choice cannot be deferred indefinitely — colloquially, choosing the “lesser of two evils.” The third of Lewin’s classic conflict types, and typically associated with high indecision, procrastination and psychological discomfort.
Awareness
Conscious perception or knowledge of internal states, such as thoughts and feelings, or of the external environment. A foundational construct across psychology, from basic perception research through to mindfulness-based clinical interventions, and generally distinguished from unconscious or automatic processing.
