RENEE MONTAGNE, Host:
Lady Macbeth famously tried to clean her conscience by rubbing invisible blood stains off her hands. Well, Shakespeare was on to something. Hand washing can ease psychological turmoil. NPR's Nell Greenfieldboyce reports that soaping up may help us feel better about choices we've made.
NELL GREENFIELDBOYCE: A few years ago, scientists discovered the Macbeth effect. Hand cleaning seemed to ease the guilt people felt after being asked to recall something unethical they'd done in the past. This fascinated Spike Lee. He's a psychology researcher at the University of Michigan, who wondered if hand washing could influence emotions beyond a sense of moral purity. After all, people have this idea of starting over with a clean slate.
SPIKE LEE: Maybe there's a broader phenomenon here. Anything from the past, any kind of negative emotional experiences, might be washed away.
GREENFIELDBOYCE: Lee says psychologists know that people usually try to soothe this inner conflict by later exaggerating the positive aspects of whatever it is they chose.
LEE: In other words, after they make the choice, they will like a chosen option more than before the choice.
GREENFIELDBOYCE: As the researchers had suspected, those left with dirty hands later gave their chosen CD a higher score than they had on the initial ranking. But the hand washers didn't.
LEE: They feel no need at all to justify the choice.
GREENFIELDBOYCE: In the journal Science, the researchers report that they saw the same effect in a similar experiment that let people use antiseptic wipes.
NORBERT SCHWARZ: Apparently you do not need water and soap.
GREENFIELDBOYCE: Norbert Schwarz says, on the one hand - so to speak - washing may help decision makers by rinsing away mental turmoil, but on the other hand...
SCHWARZ: We may not do you a favor when you wash your hands and you're not doing that cognitive work to make your decisions appear in the best possible light.
GREENFIELDBOYCE: Nell Greenfieldboyce, NPR News.
MONTAGNE: So we thought we'd end the week on a more hopeful note - this classic sung by Johnny Cash.
(SOUNDBITE OF SONG, "BRIDGE OVER TROUBLED WATER")
JOHNNY CASH: (Singing) When times get rough and friends just can't be found, like a bridge over troubled water I will lay me down. Like a bridge over troubled water, I will lay me down. When you're down and out...
MONTAGNE: This is NPR News.
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