Formal vs. intuitive categorization and obsessive-compulsive symptoms

Background and objectives: Obsessive-compulsive disorder (OCD) is often characterized by rigidity regarding rules and perfectionism, which suggests a formal reasoning style. However, other characterizations suggest an overreliance on internal cues for behavior termination, which suggests a more intuitive reasoning style. We examine reasoning styles in OCD by assessing categorization preferences traditionally classified to rule-based and family resemblance categorization. Method: An initial study (n = 41) and an online replication (n = 85) were conducted. In both studies, groups scoring high and low on OCD symptoms were compared. Categorization preferences and confidence ratings were examined via a modification of a classic categorization task. The task was administered in three conditions: under time limits, with no time limits, and with explicit explanation of both categorization styles. Results: Aggregating results from both studies showed that obsessive-compulsive symptoms were associated with a reduced preference for rule-based categorization reflecting a tendency towards a more intuitive, non-formal reasoning style. This preference was apparent even when rules were explicitly described. Group differences regarding confidence were inconclusive. Limitations: Generalizing results to the clinical population requires further research, and specificity to OC symptoms should be determined. Conclusions: Challenging the expected association between OCD and rigidity and perfectionism, findings support suggestions that OCD reasoning strays from formal reasoning. This may explain some of the subjective and idiosyncratic rules adopted by individuals with OCD.