SCIENCE
11/17/2014 01:58 pm ET

How Feelings Of Disgust Lead To Immoral Behavior

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Nobody likes to feel disgusted. But evidence suggests that disgust is an evolutionary adaptation that protects us from potentially harmful things like rotting food or filthy environments.

A 2012 study shows a provocative link between disgust and moral behavior, finding that people make more ethical decisions in the wake of disgusting experiences. However, new research suggests that just the opposite may be true.

The research, conducted by marketing experts from Rice University, Arizona State University and Pennsylvania State University, found that people are more likely to engage in immoral behaviors like lying and cheating after experiencing disgust, and that experiences of cleanliness then eliminated these negative behavioral effects.

Because disgust involves a focus on self-preservation, it may also be a driving force behind self-interested behavior, even in cases in which it requires us to behave immorally.

“When people feel disgusted, they tend to remove themselves from a situation," Vikas Mittal, marketing professor at Rice’s Jones Graduate School of Business, said in a university statement. "Small cheating starts to occur: If I'm disgusted and more focused on myself and I need to lie a little bit to gain a small advantage, I'll do that. That's the underlying mechanism."

In the first part of the study, the researchers conducted three randomized experiments meant to evoke disgust on 600 male and female subjects. In one experiment, participants watched the toilet scene from "Trainspotting." In another, they evaluated consumer products like antidiarrheal medicine, diapers, feminine care pads, cat litter and adult incontinence products. In a third experiment, participants wrote about their most disgusting memory.

Next, the subjects were tested on their willingness to lie and cheat for financial gain. The researchers found that subjects who had experienced disgust were significantly more willing to engage in self-serving behaviors than those who had not experienced disgust.

Participants were then asked to evaluate cleaning products like disinfectant and body wash. Those who evaluated the cleaning products after feeling disgust were less willing to engage in immoral behaviors than the disgusted group who did not evaluate the cleaning products. After evaluating the cleaning products, the disgusted subjects' willingness to engage in unethical behavior was on par with that of a control group that did not experience disgust.

"At the basic level, if you have environments that are cleaner, if you have workplaces that are cleaner, people should be less likely to feel disgusted," Mittal said in the statement. "If there is less likelihood to feel disgusted, there will be a lower likelihood that people need to be self-focused and there will be a higher likelihood for people to cooperate with each other."

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