Liberals and conservatives are often disgusted with one another. No surprise there.
But conservatives are literally the more easily disgusted of the two when it comes to such squeamish things as maggots, questionable toilet seats and the prospect of eating monkey meat. Such sensitivity, it seems, plays a role in their ideology and moral values.
Two joint studies released Friday from psychologists at Cornell, Harvard and Yale universities determined that conservatives are more fastidious about the creepier, smellier side of life — reflective of a hard-wired instinct for safety and self-preservation.
"It raises questions about the role of disgust — an emotion that likely evolved in humans to keep them safe from potentially hazardous or disease-carrying environments — in contemporary judgments of morality and purity," said study leader David Pizarro, an assistant professor of psychology at Cornell who led the study.
"People have pointed out for a long time that a lot of our moral values seem driven by emotion, and, in particular, disgust appears to be one of those emotions that seems to be recruited for moral judgments."
Freddy Gray, literary editor of American Conservative Magazine, finds the whole idea "extraordinarily funny."
"You can try to read profound things into these findings, but you'd risk being a pseudo-intellectual if you try to ascribe to the notion that conservatives are as uncomfortable about bugs as they are about abortion," Mr. Gray said.
"I don't think these findings about the psychological and squeamish impulses of conservatives should be taken seriously," he said. "Oh, and pardon me, I have to put down the phone because I see a spider crawling nearby. You can quote me on that."
Mr. Gray was having a little fun with the researchers, perhaps — but the team was quite serious.
The researchers surveyed 181 adults from politically mixed "swing states," offering them the "Disgust Sensitivity Scale," a personality ratings system initially developed by behavioral psychologists at the University of Virginia.
It poses all sorts of uncomfortable possibilities to participants — gauging their reactions on a scale of 1-5 to vomit, graveyards, preserved body parts, squashed earthworms and monkey meat.
The researchers surveyed the degree of ideological beliefs of the same test group, to reveal "a correlation between being more easily disgusted and political conservatism," the study said.
"Disgust really is about protecting yourself from disease; it didn't really evolve for the purpose of human morality," Mr. Pizarro said. "It clearly has become central to morality, but because of its origins in contamination and avoidance, we should be wary about its influences."
In another study, the researchers offered the disgust scale to 91 Cornell undergraduates, also asking them where they stood on gay marriage, abortion, gun control, labor unions, tax cuts and affirmative action.
"Participants who rated higher in disgust sensitivity were more likely to oppose gay marriage and abortion, issues that are related to notions of morality or purity," the study found. Squeamish people were also more likely to disapprove of gays and lesbians in general.
The findings revealed complex emotions, indeed.
"Conservatives have argued that there is inherent wisdom in repugnance; that feeling disgusted about something — gay sex between consenting adults, for example — is cause enough to judge it wrong or immoral, even lacking a concrete reason," Mr. Pizarro said.
"Liberals tend to disagree, and are more likely to base judgments on whether an action or a thing causes actual harm."
He speculated that the link between disgust and moral judgment could help explain stark differences in values among Americans — and be of interest to canny political strategists. He added that the findings "could offer strategies for persuading some to change their views."
The research was published in Cognition and Emotion and Emotion, two academic journals, and funded solely by Cornell University.
The inner leanings of conservatives and liberals, meanwhile, have drawn interest in other circles. In a study of 170 employees and students released in September, New York University psychologist John T. Jost found that conservatives favor tidy offices and living spaces, while liberals are more comfortable with cluttered desks and splashy colors.
"The findings reported here add to a growing body of literature suggesting that ideological differences are more than 'skin deep.' … As a general rule, liberals are more open-minded in their pursuit of creativity, novelty and diversity, whereas conservatives lead lives that are more orderly, conventional and better-organized," the study said.