03/23/2011 08:55 am ET Updated Nov 17, 2011

From Bitter to Wrong: Conscience of a Moral Conservative

Fans of the old sitcom "Seinfeld" will recall Mr. Bookman, the well-named New York Public Library investigator who relentlessly pursues Jerry for failing to return a library book that he checked out two decades before. Jerry borrowed the book, "Tropic of Cancer," in 1971, and when Mr. Bookman finally tracks him down, the mere mention of that year sends the library cop off on a sweeping moral tirade on the degradation of civilized culture:

Yeah, '71 ... Bad year for libraries. Bad year for America. Hippies burning library cards. Abby Hoffman telling everybody to steal books. I don't judge a man by the length of his hair or the kind of music he listens to ... But you put on a pair of shoes when you walk into the New York Public Library, fella.

Mr. Bookman's angry crusade clearly goes beyond library fines. It's personal. He doesn't like Jerry, or anything he represents, which he sums up as "flashy, making the scene, flaunting convention." For him, stealing library books is not an abstract moral violation. It's an insult to all that's sacred and decent about America, and it's disgusting on the most primitive, visceral level.

Mr. Bookman is a parody, of course -- a parody of overly moralistic conservatives. But does the caricature capture some essence of conservative moral reasoning? New research suggests that may be so. Conservative and liberal minds, it appears, may be fundamentally different psychologically, with conservatives much more sensitive to everyday triggers for physical disgust, and much more likely to commingle repulsion and moral judgment.

The new work comes from three psychological scientists at the City University of New York (Kendall Eskine, Natalie Kacinik and Jesse Prinz) who started off exploring a possible connection between morality and taste -- not aesthetic taste, but actual taste, in the mouth. A recent and growing body of research is showing that thinking and judgment can be powerfully influenced by the body and its interaction with the world. Everything from cleanliness to temperature can shape the way we think and feel, and the CUNY scientists wondered if taste might similarly mold our thoughts about right and wrong.

So they did a simple test. They recruited a group of volunteers for a study of arm-hand movements, and as part of that study they asked them to very quickly pick up and drink a "shot" of beverage. In fact, the motion study was a ruse -- a cover for the actual study. For that, some of the volunteers drank water, while others drank a sweet punch, and still others a bitter herbal concoction. The idea was to see if taste influences emotions -- especially disgust -- which in turn shape moral judgment.

They measured moral judgment using several vignettes involving transgressions. One of these vignettes had to do with, yes, unreturned library books. Others focused on corrupt politicians, shoplifters, ambulance-chasing lawyers, a man eating his dead dog and second cousins having sex. In each case, the volunteers rated the acts on a continuum from "extremely morally wrong" to "not at all morally wrong." Finally, the volunteers noted whether they considered themselves politically liberal or conservative.

When they analyzed all the data, the results were unambiguous. As reported online in the journal, Psychological Science, taste dramatically influenced moral judgment, such that physical disgust resulting from the bitter drink led to much harsher moral judgments. What's more, self-identified conservatives who drank the bitter drink were much more judgmental than conservatives who drank sweet punch or water. Liberals' moral judgments were unaffected by what they drank.

Why was this effect more pronounced in people espousing conservative politics? It's not entirely clear, but one possibility is that disgust, as an emotion, is closely connected with one's sense of purity and the violation of that sensibility. Purity norms are more prevalent in conservative than in liberal morality. This also fits well with the fact that most people can't articulate the reasons for their moral positions: When pressed for rationales, most people concede that this or that act simply "feels" right or wrong, just as Jerry's overdue book upset Mr. Bookman at his very core.