behaviouralismPronunciation: /bɪˈheɪvjərəlɪz(ə)m/ (US behavioralism)Definition of behaviouralism noun [mass noun] the methods and principles of the scientific study of animal (and human) behaviour. advocacy of or adherence to a behavioural approach to social phenomena. Derivatives behaviouralist noun & adjective behaviouralism in other Oxford dictionaries Definition of behaviouralism in the US English dictionary