Conservatives aren't just disgusted by hippies and liberals - they're more likely to be disgusted by everything else too.
Political scientists have measured people's physiological reactions when looking at a series of pleasant and unpleasant images, and found the conservatives are much more likely to be revolted by the nasty ones.
Those who said they were against gay marriage showed the strongest reactions to the pictures, which included people eating worms and bloody wounds.
"This is one more piece of evidence that we, quite literally, have gut feelings about politics," University of Nebraska-Lincoln political science professor Kevin Smith. "Our political attitudes and behaviors are reflected in our biology."
The finding echoes previous research, which has found that people who respond strongly to threatening images were more likely to support defense spending, capital punishment, patriotism and the Iraq War.
"The proper interpretation of the findings [in the current study] is not that biology causes politics or that politics causes biology, but that certain political orientations at some unspecified point become housed in our biology, with meaningful political consequences," the authors write.
But most people are reluctant to accept that there's a physiological element, they say: "Most are proud of their political orientations, believe them to be rational responses to the world around them, and are reluctant to concede that subconscious predispositions play any role in shaping them."
Rather optimistically, the authors suggest that if people were more prepared to accept this, the world would be a more peaceful place.
"After all, if political differences are traceable in part to the fact that people vary in the way they physically experience the world, certitude that any particular world-view is 'correct' may abate, lessening the hubris that fuels political conflict," they say.