Clean hands, but a foul mouth!

Lady Macbeth is history’s most famous washer, hands down. Plagued by guilt for plotting her king’s murder, she scrubs and scours her palms and knuckles to get rid of imagined blood stains. But all the scrubbing can’t cleanse her impure heart.

Or mind, as psychological scientists like to think of it. Researchers have discovered in the past few years that moral purity is no mere metaphor–that we all physically embody both our malevolent thoughts and our repentance. Soap and water can literally salve our guilt, and soften our moral judgments of others, while moral transgressions can send us searching for wash cloths and disinfectants.

Research now suggests that our bodies’ version of morality may be even more precise than we thought. A new study by Spike W.S. Lee and Norbert Schwarz, cognitive psychologists at the University of Michigan, suggests that while some of us may indeed have guilty hands in the manner of Lady Macbeth, others of us might be impure of mouth–depending on the precise form of the immoral act. And of course, dirty hands and foul mouths require different kinds of moral purification.

The experiment started with this imaginary scenario: You are an associate in a large law firm, competing with a colleague for promotion. You find an important legal document that your colleague has lost, which creates this dilemma: Do you return the document, helping your competitor and hurting your own chances for promotion? Or do you keep the discovery to yourself?

All of the volunteers actually contacted their imaginary colleague and left a message, half by voicemail and half by email. In addition, half lied and half told the truth, so that there were in all four kinds of messages: spoken lies, spoken truthfulness, honest writing and dishonest writing. The idea was to implicate either the mouth or the hands in ethical and unethical acts.

Then, under the pretense that they were participating in a marketing study, all the volunteers rated the desirability of a whole array of consumer products–and how much they were willing to pay for each. Among the products–and the only ones that really mattered to the study–were mouthwash and hand sanitizers. The scientists recorded who was in the market for what.

The results? As reported online in the journal Psychological Science, the “lawyers” who had lied by voicemail were much more interested in mouthwash than were those who left dishonest email messages. Those who lied by email–a particularly craven form of dishonesty–were drawn to the hand sanitizers. Out, out damn spot. What’s more, those who did the right thing–sending an email alerting their colleague about the lost document–actually wanted the hand sanitizers less than any of the others–as it they didn’t want to wash away the good essences they acquired from their virtuous actions.

This is the first study to explore the physical embodiment of virtue, but interestingly, the volunteers did not view mouthwash in the same way. That is, they did not appear worried about washing away the residue of their virtuous spoken words. The scientists think this may have to do with language itself: In natural parlance, the metaphor “clean hands” is common and accessible, but “clean mouth” is not. So it may be that the mixing of dirt and turpitude begins with the metaphor, rather than the other way around.