By: Nell Greenfieldboyce, NPR
Friday, May 07, 2010

Soaping up your hands may do more than just get rid of germs. It may scrub away the inner turmoil you feel right after being forced to make a choice between two appealing options.

That's according to a new study on the psychological effects of hand washing in the journal Science. The study builds on past research into a phenomenon known as "the Macbeth effect."

It turns out that Shakespeare was really onto something when he imagined Lady Macbeth trying to clean her conscience by rubbing invisible bloodstains from her hands. A few years ago, scientists asked people to describe a past unethical act. If people were then given a chance to clean their hands, they later expressed less guilt and shame than people who hadn't cleansed.

This finding fascinated Spike W. S. Lee, a psychology researcher at the University of Michigan, Ann Arbor. He wondered if hand washing could restore more than just a sense of moral purity. After all, "cleanliness is next to godliness," but people also often talk about "starting over with a clean slate."

To listen to an interview with Spike W. S. Lee on American Association for the Advancement of Science website click here, please note his interview starts about 9 minutes into the 37 minutes show.

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To read the entire news release, see NPR's website at http://www.npr.org/templates/story/story.php?storyId=126558837.