The Paradoxical Effect of Repeated Body Checking on Subjective Uncertainty

Body checking is considered a behavioral expression of the core psychopathology of eating disorders (EDs), namely, overvaluation of body weight and shape. Compulsive checking is motivated by a desire to increase a sense of certainty regarding feared outcomes. Paradoxically, studies showed that repeated checking acts to reduce certainty, forming a vicious cycle. No previous study examined whether the same principle applies for body checking. This study filled this gap by examining the causal effect of repeated body checking on memory certainty regarding checked body parts.

In a laboratory-based study, 77 female participants without an ED checked the size and shape of six body parts. Their objective memory regarding which body part was last checked, and subjective certainty about this memory were assessed. Then, one group of participants continued to engage in repeated body checking, and another group repeatedly checked a neutral object. Finally, all participants completed the six body parts checking procedure again, and their objective memory and memory certainty were re-assessed.

In both checking groups, objective memory regarding the last body part checked was unaffected by the type of checking performed. Importantly, certainty about memory dropped considerably only among those in the repeated body-checking group.

The findings provide the first empirical evidence of a paradoxical effect demonstrating that repeated body checking reduces certainty about checked body parts. The study implies that repeated body checking reduces the quality of information obtained through checking and, as such, could potentially motivate further checking.