Washing away your sins will set your mind free: physical cleansing modulates the effect of threatened morality on executive control

The effect of threatened morality on negative emotions and on altruistic behaviour has been shown to diminish following physical cleansing (hand-washing). We hypothesised that threatened morality will broadly impair the executive control system, and that physical cleansing will moderate this detrimental effect. Thirty-seven participants were asked to write about an immoral deed they had committed, whereupon half of them were allowed to wipe their hands. Three executive control tasks—Stroop, stop-signal, and object interference—were then administered to all participants. Participants who had not wiped their hands, but not those who did, demonstrated impaired performance, compared to hand-washing controls, in all three tasks. We conclude that threatened morality has a detrimental effect on executive control, specifically on conflict monitoring and response inhibition, and that physical cleansing “frees” this system, counteracting the detrimental effects of morality threats. We discuss possible implications for obsessive–compulsive disorder, which is characterised by deficient executive control and in which both threatened morality and physical cleansing are central concerns.