60秒科学:洗洗手再做决定吧！（在线收听）

We’ve all agonized over difficult decisions. Go to college or backpack around Europe? Buy or rent? Apple pie or death by chocolate?

Well, agonize no more—because a study in the journal Science suggests that simply washing your hands after making a tough choice can keep you from second-guessing.

Washing your hands of a situation is a powerful metaphor. But scientists got to wondering, could it be something more? Previous studies had shown that washing can remove the guilt people feel about past misdeeds. But is that because the brain somehow links physical and moral cleanliness? Or because ablution washes away the past?

To find out, psychologists removed any moral implications from a forced decision. They asked students to choose between things like a pair of CDs or two flavors of jam.

They found that subjects who washed their hands right after making their choice didn't look back. They made peace with their picks and moved on—whereas those who didn't have access to soap spent more time trying to justify which jam they took home.

So if you want to avoid rethinking the past, lather and rinse. And if necessary, repeat