This study tests explanations of why some people experience intrusive thoughts as problematic, and others experience them as benign. Six-hundred and ninety non-clinical participants completed questionnaires. Results provide support for the hypothesis that the interaction between three variables (i.e., shame-proneness, thought action fusion-morality beliefs and obsessions) predicts compulsions. The relationship between obsessions and compulsions was stronger as a function of shame-proneness and thought action fusion-morality beliefs, such that the highest levels of compulsions were found for those who had the highest levels on all three predictors. No support was found for the hypothesis that the relationship of these three predictors with compulsions is mediated by intrusion-related self-inferences, nor for the hypothesis that another interaction between three variables (i.e., guilt-proneness, TAF-likelihood beliefs, and obsessions) also predicts compulsions. These results are consistent with the ideas that shame and thought action fusion beliefs play a role in the development of obsessive compulsive disorders.