Does Washing Your Hands Make You Less Judgmental?

By Nina Bai | December 1, 2008 3:22 pm

hand washDefense lawyers take note: Be sure to have some Purell to offer the jury before they deliver the verdict—their clean hands could help your case.

New research in Psychological Science [pdf] suggests that outer cleanliness can loosen people’s moral judgment. While many of us may have experienced the “Macbeth effect,” in which people feel the need to purify themselves after a sinful act, researchers now find that people who had first scrubbed their hands rated sinful acts less harshly.

Researchers asked 40 participants to rate morally questionable situations on a scale from one (perfectly OK) to nine (extremely wrong). The situations ranged from taking money from a found wallet, to eating the family dog to avoid starvation, to “using a kitten for sexual arousal” (seriously). The researchers prepped the participants by asking them first to unscramble sentences. One group was given sentences containing “clean” words like “pure,” “washed,” and “pristine,” while another group was given sentences with neutral words. The clean group gave lower ratings to the objectionable situations—6.7 for some kinky kitten play compared to 8.3 from the neutral group, for example.

In a follow-up experiment, researchers first elicited feelings of dirtiness and disgust in the participants. How did they do this? By making them watch clips of Trainspotting. Afterwards, one group was asked to wash their hands. That group also rated the morally objectionable situations less severely.

The researchers think the participants were transferring their physical sensations—in this case, of purity or disgust—onto their moral decisions. Previous studies have found similar body-mind connections between physical warmth and generosity as well as physical chill and social exclusion. Now, it looks like we may have a link between good hygiene and libertine habits—which should give pause to those who insist that cleanliness is next to godliness.

Related Content:
80beats: Warm Hands Give People a Friendly, Generous Outlook
80beats: Social Isolation Makes People Crave a Warm Bowl of Soup
DISCOVER: The Biology of …Hand-Washing

Image: flickr / SMercury98

CATEGORIZED UNDER: What’s Inside Your Brain?

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