Everyone knows they should wash their hands after using the bathroom, but that doesn't mean everyone does it – particularly men.
According to a 2010 study, 93 percent of women scrub up after using a public restroom, while only 77 percent of men do the same.
To see if public-health messages could get men to clean up their acts, researchers infiltrated undergraduate men's bathrooms at Michigan State University. On the walls, the scientists put up posters that showed various combinations of students from MSU or other schools with variations on information about hand-washing.
A poster with one of the strongest messages, for example, showed the backs of five college-age males facing urinals. Four wore backward-facing MSU baseball caps, while one whore a cap from a rival university. At the bottom of the poster were the words: ‘‘Four out of five college students wash their hands EVERY time they use the bathroom.'' In a series of experiments, researchers entered the poster-decorated bathroom behind randomly chosen men. Then, they pretended to scrub a stain on their shirts, while observing how many men washed their hands and how thoroughly they scrubbed. They also interviewed men after bathroom use.