The purpose of these studies was to provide the first experimental tests of a new
cognitive theory of compulsive checking by Rachman (2002). The first part of this theory
concerns the impact of hypothesized "multipliers" of checking, perceived responsibility,
probability, and severity of harm. Study 1 assessed the impact of these multipliers on a
variety of checking-related outcomes. Fifty undergraduate students, 31 participants with
anxiety disorders other than obsessive-compulsive disorder (OCD), and 29 participants with
OCD responded to a series of vignettes describing situations that implied the possibility of
harm. Participants provided ratings of their likely emotional and behavioural responses in
these situations. It was hypothesized that the multipliers would make significant independent
and combined contributions to checking-related outcomes. The findings of Study 1 offered
strong support for part one of the theory and highlighted its explanatory power across the
continuum of anxiety and checking behaviour.
Study 2 provided the first exploratory test of the self-perpetuating mechanism
described in part two of Rachman's theory as an explanation for repeated checking. It was
hypothesized that repeated checking would be associated with increases in perceived
responsibility, probability and severity of harm, and with decreased confidence in memory,
consistent with the proposed self-perpetuating mechanism. Study 2 also explored the
universality of this mechanism by testing both individuals who routinely check and those
who do not, and by including both high and low relevance items. Forty-four undergraduate
students and 20 individuals with OCD and primary checking compulsions completed a
telephone checking experiment from their homes. Participants performed a series of four
checking tasks under the telephone guidance of an experimenter. Two of the tasks involved a
single check of the items (high relevance vs. low relevance) and two of the tasks involved
repeated checking. Contrary to hypotheses, ratings of responsibility, probability and severityThe purpose of these studies was to provide the first experimental tests of a new
cognitive theory of compulsive checking by Rachman (2002). The first part of this theory
concerns the impact of hypothesized "multipliers" of checking, perceived responsibility,
probability, and severity of harm. Study 1 assessed the impact of these multipliers on a
variety of checking-related outcomes. Fifty undergraduate students, 31 participants with
anxiety disorders other than obsessive-compulsive disorder (OCD), and 29 participants with
OCD responded to a series of vignettes describing situations that implied the possibility of
harm. Participants provided ratings of their likely emotional and behavioural responses in
these situations. It was hypothesized that the multipliers would make significant independent
and combined contributions to checking-related outcomes. The findings of Study 1 offered
strong support for part one of the theory and highlighted its explanatory power across the
continuum of anxiety and checking behaviour.
Study 2 provided the first exploratory test of the self-perpetuating mechanism
described in part two of Rachman's theory as an explanation for repeated checking. It was
hypothesized that repeated checking would be associated with increases in perceived
responsibility, probability and severity of harm, and with decreased confidence in memory,
consistent with the proposed self-perpetuating mechanism. Study 2 also explored the
universality of this mechanism by testing both individuals who routinely check and those
who do not, and by including both high and low relevance items. Forty-four undergraduate
students and 20 individuals with OCD and primary checking compulsions completed a
telephone checking experiment from their homes. Participants performed a series of four
checking tasks under the telephone guidance of an experimenter. Two of the tasks involved a
single check of the items (high relevance vs. low relevance) and two of the tasks involved
repeated checking. Contrary to hypotheses, ratings of responsibility, probability and severity decreased significantly and memory confidence increased significantly from pre- to post-check
across both the single and repeated check conditions and both samples. The findings of
Study 2 were not consistent with the operation of a self-perpetuating mechanism.
Implications of the findings of these studies for this new cognitive theory of compulsive
checking are discussed.Arts, Faculty ofPsychology, Department ofGraduat
