Glossary of Psychological Terms
Definitions of terms used in psychology, psychometric testing and occupational assessment, organised alphabetically.
Habit
A learned response to a given situation, performed so regularly that it appears virtually automatic — closely enough resembling innate behaviour that habits are sometimes mistakenly regarded as instincts.
Hallucinogen
A drug, such as LSD or mescaline, capable of inducing hallucinations — perceptual experiences with no corresponding external stimulus.
Hawthorne effect
The finding that simply paying attention to workers improves their performance, first identified in studies at the Hawthorne Works of the Western Electric Company in Illinois during the 1920s. Researchers varied conditions such as lighting, rest breaks, working hours and pay systems; each change increased productivity — as, eventually, did reverting to the original conditions. The investigators concluded that it was not the specific environmental changes that mattered, but workers' perception that management was taking an interest in them and their work — a striking example of social facilitation.
Hebephrenia
An older term for a form of schizophrenia characterised by giggling, silliness, and displays of emotion inappropriate to the situation; now generally subsumed under broader schizophrenia diagnostic categories.
Heredity
The biological transmission of physical and, to a debated degree, psychological characteristics from parents to their offspring via genes.
Heuristic
Originally, a method or idea in teaching that stimulates further thinking and discovery; now used more broadly for any mental rule of thumb or shortcut that helps a person make a decision or solve a problem quickly, often at some cost to accuracy.
Higher mental processes
A general term for thinking — including learning, memory, reasoning and imagination — as distinct from more basic sensory processes.
Horopter
In binocular vision, when both eyes are fixed on the same point, the horopter is the set of all points in space whose images fall on corresponding locations on both retinas, and which are therefore perceived as a single, fused image rather than as double vision.
Human communication
The exchange of information between people by any means — verbal, through speech and writing, or non-verbal, through gesture, expression and tone. The study of the field draws on psychology, social science, linguistics, computer science and logic.
Human engineering
See ergonomics — the study of the interaction between people and the tools, machines and environments they work with.
Human factors
See ergonomics.
Human performance factors
The American term for ergonomics.
Humanistic psychology
A school of psychology emphasising the qualities that distinguish human beings from other animals — creativity, humour, play and psychological growth. Sometimes called the “third force” in psychology, positioned as an alternative to both behaviourism and psychoanalysis. Its leading figures include Gordon Allport, Abraham Maslow and Carl Rogers.
Huntington's chorea
Also called Huntington's disease: a hereditary, progressive neurodegenerative disorder affecting muscle coordination and leading to cognitive decline and dementia, typically becoming apparent in middle age. It is the most common genetic cause of chorea — involuntary, writhing movements — and occurs considerably more often in people of Western European descent than in those of Asian or African descent.
Hydrocephalus
A condition involving an excessive build-up of cerebrospinal fluid within the skull, resulting in an enlarged skull and, without treatment, underdeveloped brain tissue.
Hydrophobia
Literally, “fear of water”: the medical term for a symptom of rabies in humans, in which attempting to swallow triggers throat spasms. Despite the name, the fear involved is a direct physiological symptom of the disease, not a psychologically abnormal phobia.
Hyperthyroidism
A condition of excessive hormone secretion by the thyroid gland, which can produce heightened physical activity, restlessness and emotional excitability.
Hypnagogic images
Vivid, often hallucinatory images and sensations experienced during the transitional period of falling asleep.
Hypnogenic
Describing anything that helps induce a state of hypnosis.
Hypnosis
An induced state of heightened suggestibility to a hypnotist's instructions. Though the typical hypnotic trance outwardly resembles sleep, EEG recordings show it is a distinct physiological state. Despite centuries of interest, the underlying mechanism of hypnosis remains poorly understood, though it is a clearly real and, in the right circumstances, powerful phenomenon — as far back as the mid-nineteenth century, surgeons James Braid and James Esdaile reportedly performed battlefield surgery using hypnosis as the sole anaesthetic, a practice that ended with the introduction of chloroform.
Hypnotherapy
The therapeutic use of hypnosis within psychotherapy, for purposes such as pain management, habit change or accessing suppressed memories.
Hypochondria
A neurotic, excessive preoccupation or worry about having a serious illness, often persisting even after a physician has thoroughly evaluated a person and found no underlying medical cause — or, where illness is present, worrying far beyond what the actual severity warrants. Many people with hypochondria fixate on a particular set of symptoms, such as gastrointestinal complaints, heart palpitations or muscle fatigue, as the focus of their anxiety.
Hypothalamus
A small but critical region at the base of the brain responsible for regulating many basic bodily processes, including temperature, hunger, thirst and the release of hormones via the pituitary gland.
Hypothesis
A proposed explanation for an observed pattern of data, put forward in a form that can be tested through further observation or experiment.
Hypothetical construct
A theoretical concept, invented by a researcher or theorist to make sense of an observed phenomenon, without necessarily being directly observable itself — an ordinary and essential part of scientific progress, applying as much to a physicist's “atom” as to a psychologist's “personality.”
Hysteria
From the Greek word for “womb,” reflecting the historically mistaken belief that the emotional disturbances it describes were exclusively female and caused by disorders of the uterus. There is no full consensus on hysteria's defining symptoms, though most authorities treat dissociation as a central feature; conversion hysteria is its most striking recognised form. Psychoanalysis treats all hysteria as a form of neurosis arising from unconscious conflict. See also: battle fatigue, sometimes described as a male-presenting form of hysteria.
Hysterical paralysis
See conversion hysteria — the loss of motor function in a limb or body part with no identifiable physical cause, understood as a physical expression of underlying psychological conflict.
