Responsibility, probability, and severity of harm: An experimental investigation of cognitive factors associated with checking-related OCD.

The cognitive model of compulsive checking (Rachman, 2002) proposes that perceptions of responsibility, seriousness of harm and probability of harm interact to promote checking behaviour. We examined these factors in an ecologically valid experimental paradigm. Two groups of participants (participants with OCD who compulsively check and undergraduate controls) were assigned to a high or low responsibility condition, and then checked objects representing: (a) high seriousness of harm (stove burners), (b) low seriousness of harm (light bulbs), (c) high probability of harm (functional burners and bulbs), and (d) low probability of harm (non-functional burners and bulbs). In general, a diagnosis of OCD, as well as conditions of increased severity/likelihood of harm, and to a lesser degree, increased responsibility, led to a greater period of time spent checking. Implications for the cognitive-behavioural model of and treatment for compulsive checking are discussed.