In thinking about why disgust sensitivity may be associated with conservative moral values, researchers have considered the potential connection between the behavioral immune system and religion. Religious strictures and other traditions may have the hidden function of protecting us from disease, some theorize. Our urge to respect certain culinary practices, sexual prohibitions, and injunctions about washing and hygiene may not be just about achieving spiritual or symbolic purity, but may be the result of an evolutionary drive to avoid contamination.

Could a predilection toward revulsion indicate how we vote? A team led by Cornell’s David Pizarro and Yoel Inbar, at the University of Toronto, set out to answer that question by conducting an online study during the 2008 U.S. presidential contest between Barack Obama and John McCain. In the run-up to the election, the researchers assessed the contagion anxiety of 25,000 “demographically and geographically diverse” Americans and then surveyed the attitudes toward the candidates held by a random subset of the larger group. Those with the highest germ fear reported that they were more likely to vote for McCain, the Republican nominee and the more conservative candidate. Further, the actual proportion of votes that went to him in each state directly scaled with that state’s level of contagion anxiety. The researchers eventually extended studies of this kind to 121 countries and found that disgust sensitivity correlated with a conservative ethos basically everywhere there were sufficient data for analysis. As Pizarro, Inbar, and the other authors of the study write in the journal Social Psychological and Personality Science, this result suggests that disgust sensitivity “is related to conservatism across a wide variety of cultures, geographic regions and political systems.”