Now wash your hands

It's official - men really are more dirty than women. One in four men don't wash their hands after using the toilet, compared with one out of ten women, according to figures from the American Society for Microbiology, writes David Fickling

It's enough to make you think twice about shaking hands quite so readily. Tellingly, when researchers interviewed people over the phone, only 3% or 4% of them owned up to their filthy habits.

To get around this problem, the fearless academics had to sneak around in toilets watching where people put their hands.