The earliest description of behavioral treatment of obsessive-compulsive disorder (OCD) was by Vic Meyer (1966), in a paper titled Modification of expectations in cases with obsessional rituals. This work formed the nucleus of what came to be known as exposure and response prevention (ERP) (Rachman and Hodgson, 1980). This cognitive emphasis in the earliest description of behavioral treatment reflects a recurring theme throughout the theoretical, experimental, and clinical development of this line of psychological treatment. However, the importance of cognitive factors was reflected in a more diffuse understanding of their likely significance rather than a specific recognition of their nature. For example, Marks in 1981 pointed out that:

In 1976, Rachman and colleagues had more systematically identified a similar phenomenon as an intriguing observation during experiments on the “spontaneous decay” of compulsive urges. In this ground-breaking series of experiments, the researchers both predicted and demonstrated that behavioral rituals were associated with an immediate reduction in discomfort and urge to ritualize further rather than an increase (as predicted by other theories current at that time). A subsequent reduction of discomfort and the urge to wash in people who did not engage in their ritual over the longer term was also noted.