What does behaviour mean?
Behaviour is the manner in which a person, animal, or thing acts, especially in relation to others or in response to specific circumstances. When applied to people, the word often carries a moral or evaluative dimension: we speak of good, bad, rude, or exemplary behaviour, judging conduct against social expectations. In science the term is strictly neutral, describing anything observable — the foraging behaviour of bees, the thermal behaviour of metals, or the behaviour of markets. Spelled 'behaviour' in Britain and most Commonwealth countries but 'behavior' in the United States, the word derives ultimately from Old English roots meaning 'to have or hold oneself', which explains its core sense: how one carries oneself. Its derivatives include behavioural (adjectival), behaviourally, and behaviourist terms tied to the psychological school of behaviourism, which insisted on studying outward actions rather than unobservable inner states. Few everyday nouns range so naturally from nursery reprimands to laboratory research reports.
The way in which a person, animal, or thing acts or conducts itself, especially toward others.
"His behaviour towards his colleagues was always courteous."
When referring to people, often carries an evaluative sense judged against social norms.
The observable activity or functioning of an organism, system, or substance, especially in scientific study.
"The study examined the feeding behaviour of humpback whales."
In scientific contexts the word is descriptive rather than evaluative.
Usually uncountable when referring to conduct in general ('bad behaviour'), but takes a plural form in scientific contexts when discussing multiple distinct patterns of action.
"The researchers catalogued several distinct mating behaviours across the species."
The word 'behaviour' contains 'haviour' — a now-obsolete English noun meaning 'having' or 'holding' — so to behave is literally to 'carry yourself' in a certain way.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of behaviour
Behaviour comes from the verb 'behave', formed in late Middle English from 'be-' plus 'haviour', a variant of 'havour' meaning possession or bearing, itself derived from the verb 'have'. Thus the original sense was literally how one 'has' or 'holds' oneself. The word became established in English by the early modern period and later gave rise to the adjective behavioural and the psychological school of behaviourism in the early twentieth century. It shares the root verb 'have' with words such as 'habit', via Latin 'habere', though these are more distant cousins than direct siblings.
Related word forms
How behaviour is actually used
Spelled with -our in British English and -or in American English ('behavior'); both are fully standard. The word carries a slightly evaluative edge when applied to people — praising someone's 'good behaviour' implies a norm from which one can depart — whereas in scientific contexts it is entirely neutral and descriptive. In formal psychology, 'behaviour' is central to behaviourism, the school that studies only observable actions rather than inner mental states.
Easily confused with behaviour
'Behavior' is simply the American spelling of the same word; 'behaviour' is the British spelling — they mean exactly the same thing.