ABSTRACT
The behaviourism of John Watson and B. F. Skinner arose, in part, as a reaction to the relatively introspective, non-empirical approach Freud took toward psychology (e.g. Watson, 1913). The principles of operant and respondent (or classical) conditioning relied solely on directly observable variables, and both Skinner and Watson placed primary emphasis on pragmatics. In other words, rather than ``explaining'' behaviour at multiple levels of analysis, their parsimonious theories of behaviour largely sought to enhance the degree to which one could predict what organisms would do under particular circumstances and control or systematically change those behaviours using operant and respondent principles (e.g. Smith, 1992). Perhaps not surprisingly, exposure-based behavioural treatments for problems like anxiety and fear proved to be relatively brief and effective from early on (e.g. Jones, 1924; Wolpe, 1958), with operant approaches to the treatment of depression (e.g. Ferster, 1973) and a variety of developmental disabilities (e.g. Baer, Wolf, & Risley, 1968) arising as similarly effective treatments later on. This tide of empirically supported behavioural momentum eventually came to be known as the ``First Wave'' of behaviour therapy (Hayes, 2004a).
