be ‧ hav ‧ iour ‧ is ‧ m BrE AmE British English , behaviorism American English /bɪˈheɪvjərɪz ə m/ noun [uncountable]
[ Word Family: noun : BEHAVIOUR/BEHAVIOR , MISBEHAVIOUR/MISBEHAVIOR , BEHAVIOURISM/BEHAVIORISM , BEHAVIOURIST/BEHAVIORIST ; verb : ↑ behave , ↑ misbehave ; adverb : BEHAVIOURALLY/BEHAVIORALLY ; adjective : BEHAVIOURAL/BEHAVIORAL ]
the belief that the scientific study of the mind should be based only on people’s behaviour, not on what they say about their thoughts and feelings
—behaviourist noun [countable]