Wash your hands for happiness

Handwashing makes people more at ease with decisions.

Lady Macbeth may have been on to something, according to a team of psychologists who have found that handwashing has both physical and emotional benefits, and helps people to feel more at ease about decisions they have made. The study, which was carried out at the University of Michigan in the US, showed that those who washed their hands after making a difficult decision felt happier about their choice than those who didn't. Hand washing, they say, is a way of drawing a line under something in psychological terms, and of removing doubts about whether you have done the wrong thing.

The study involved a group of students who had to choose 10 of their favourite CDs from a selection of 30 and rank them in order of preference. Half of them went to wash their hands afterwards. Those people, said the researchers, did not feel the need to justify their decision when they ranked them for a second time. "The results show that as much as washing can cleanse us from traces of past immoral behaviour, it can also cleanse us from traces of past decisions, reducing the need to justify them," said Professor Norbert Schwarz, the co-writer of the study.

Such a pyschological tic evidently did not help Lady Macbeth that much in the end; but it may prove useful for newlyweds, whose lasting happiness apparently rests on whether or not both parties take a trip to the bathroom after the ceremony.