The paper examines the influence of behaviourism on vocational education and training in Britain in the period between the Second World War and the mid-1970s. By the 1970s, behaviourism provided deeply-rooted underlying curricular and pedagogic principles that were widely accepted by VET professionals in the UK. Insofar as behaviourist ideas were debated, critics focused on the rigidity with which they were applied in practice, rather than on the ideas themselves. The paper explores the context within which behaviourist ideas came to dominate the VET profession, outlining their operationalisation as "programmed instruction" (later as "programmed learning"), and showing how their advocacy and adoption helped to underpin the emergence of a professional community of VET scholars and practitioners. The paper draws largely on contemporary evidence, including professional journals, textbooks and official records, as well as archival materials. It concludes by challenging simplistic dismissal of programmed instruction as mechanistic, utilitarian and reductionist.