A study published in the September issue of the Journal of Experimental Social Psychology found that test subjects who felt physically clean were more likely to perceive themselves as morally pure as well — and to sit in judgment of others. 

In one experiment involving 58 students, half were asked to washed their hands using an antiseptic cleaner, while the rest were not. Later, all of the students were asked to rate the morality of several societal issues, including smoking, pornography, profane language, littering and adultery. The students who had washed their hands were firmer in their judgments than those who did not.  

“Acts of cleanliness have not only the potential to shift our moral pendulum to a more virtuous self, but also license harsher moral judgment of others,” the study’s authors said.