Soaping up your hands may do more than just get rid of germs. It may wash away the inner confusion you feel right after being forced to make a choice between two appealing choices, according to a new study. 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（良心）by rubbing invisible bloodstains from her hands. A few years ago, scientists asked people to describe a past wrong act. If people were then given a chance to clean their hands, they later expressed less guilt than people who hadn't cleaned.
This finding fascinated W. S. Lee, a researcher. “Anything from the past, any kind of negative emotional experiences, might be washed away,” says Lee.
He decided to test hand washing's effect on one kind of bad feeling: the tension we feel after being forced to choose between two attractive choices, because picking one choice makes us feel that we've lose the other. People usually try to calm this inner conflict by later exaggerating（夸大）the positive aspects of their choice.
He had students rank 10 different music CDs. Then be offered students one CD as a gift. Some students then use liquid soap. Others only looked at the soap or sniffed（噢）it. “Actually, you do not need water and soap,” says Lee.
Later, the students again had to rank all the music. People who didn't wash their hands had the normal response — they scored their take-home CD higher. Suggesting that they now saw it as even more attractive than before. But this wasn't true for the hand washers. They ranked the music about the same. “they feel no need at all to justify the choice,” say Lee.
But the implications of it just aren't clear. Schwarz says it's too soon to know whether people should head for a sink after making a tough choice. He says washing may help decision-makers by cleaning away mental disorder, but perhaps if they don't go through the usual post-decision process of justifying their choice, they might feel more sorrow in the long run.
