With influenza season in full course, it’s good to have scientific researchers on top of a major factor relating to flu spread — handwashing.

A study by British researchers asks who is doing it and why?

This matters greatly in designing a program to change behavior — think swine flu’s spread — and the London School of Hygiene and Tropical Medicine understands that. It released the results of a study published in the American Journal of Public Health to coincide with today’s second annual Global Handwashing Day.

Researchers did reconnaissance on 250,000 people who used restrooms at a service station in England from July through September.

The subjects were greeted by messages on LED screens at the entrance to the restrooms that encouraged handwashing, using suggestions from various “behavior domains” such as knowledge of risk (Water doesn’t kill germs, soap does), status/identity (Don’t be a dope, wash with soap), disgust (Soap it off or eat it later) and norms/affiliation (Is the person next to you washing with soap?).

The effects of the messages on behavior were measured in incidences of handwashing captured through soap-dispensing sensors, with the results stored on a computer.

We would give this study an A for ingenuity as well as thoroughness. So, what washed up?

Handwashing rates between men surveyed (108,000 restroom uses) and women (90,000 restroom uses) varied widely, with women twice as likely to wash their hands (64 percent) as men (32 percent). Are we surprised? (Only that men used the bathroom more …)

Motivation varied between the genders, with women more motivated by knowledge activat ion, positive control and knowledge of risk and men more motivated by disgust.

Even researchers were a little taken aback.

They noted that women “have a higher disgust sensitivity than men” but speculated that women do respond to disgust, however, they respond more strongly to knowledge-based messages or the mention of germs than to disgust-based messages. Hmmmm.

There was some common ground — a message both genders seemed to respond to and at higher incidence than other messages: “Is the person next to you washing with soap?” Researchers found handwashing increased when more than one person was in the restroom, with a slightly higher increase among the men.

Overall finding: Call it what you may — peer pressure, shame, wanting to be part of the norm — people wash their hands more when under some sort of surveillance — from their fellow humans.

So, although the United St

ates is not among the 73 countries around the world participating in Global Handwashing Day, Americans might tip their hats to the British, who have identified social factors likely to be effective in increasing that all-important handwashing.

And remember, President Obama has asked us to do it. He won’t be watching, but someone else may be.

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