The good news about hand washing is that 96 percent of Americans do it every time they use a public bathroom. Or, that’s what 96 percent of Americans say, anyway.
Such self-reported behavior is too good to be true, of course, so when researchers from the American Society for Microbiology want to know the dirty truth about human hygiene, they don’t just conduct phone interviews: they go hide in crowded bathrooms—Atlanta’s Turner Field, New York’s Grand Central Station, San Francisco’s Ferry Terminal—and surreptitiously take notes.
The results aren’t so reassuring. An observational study by the ASM in 2010 found that just 65 percent of dudes at Turner Field soaped up before heading back to watch the game, a lousy showing compared to the 98 percent of ladies who did so. Shoppers at a San Francisco farmers’ market had markedly better habits, washing up close to 90 percent of the time, while just four in five New Yorkers hurrying to catch a train did so. (And all those were higher than similar rates reported in a study looking at a British gas station bathroom.)
How to motivate the unwashed masses? We’ve written in the past about “normative messaging”: using descriptive norms (“Eighty-five percent of homeowners turn down the thermostat when they leave the house”) to spur humans to change their behavior. Social psychologists like Robert Cialdini have demonstrated that we care as much about doing what is popular as what is right, and we search for shortcuts to inform our decisions. As the authors of a new paper on normative messaging and hand washing put it, “When a behavior is prevalent, people assume that engaging in the behavior must be the wise thing to do and, thus, will be more likely to do it.”
The subjects of the study, which appears in Human Communication Research, were 252 male students at a large Midwestern university. To inject some humor into their messaging, the psychologists designed a poster where five men stand at urinals, their backs to the viewer. Four wear baseball caps from the home university (say, Ohio State) and one wears a rival cap (say, Michigan). “Four out of five college students wash their hands EVERY time they use the bathroom,” reads the tagline.
In a separate condition, the authors tweaked the poster to show one friendly fan and four rivals, with the tagline, ‘‘One out of five college students wash their hands EVERY time they use the bathroom.’’
Normative psychology predicted that men who saw the higher statistic (i.e. 80 percent of guys wash up) would be more likely to head for the sink than men who saw the lower figure (i.e. 20 percent).
But, oddly, when an observer hid in a closed stall and took notes, the reverse proved true: for reasons the psychologists were at a loss to explain, men who saw the low statistic washed up more often (88 percent of the time) than their classmates (81 percent). Both groups did better than control subjects, only 70 percent of whom rinsed off.
In a related line of inquiry, the psychologists tested an “observer effect” on hand washing by having the note-taker occasionally leave his stall and pretend to scrub a stain at the sink. Across all conditions, when unsuspecting subjects believed they were alone in the bathroom, just 75 percent washed their hands. When they knew they were being watched, however, the figure jumped to 86 percent.
The results suggest we still have much to learn about normative messaging. The satirical poster motivated action, but not necessarily in the way theory predicted. Most of the effect, it seems, came from being explicitly reminded to wash up, and not from subtle hints about the popularity of good hygiene. Global Handwashing Day still has its work cut out for it. In other areas, of course, from energy conservation to seatbelt use to responsible drinking, descriptive norms have proved more powerful. Do norms only work for public behavior? Are there certain bad habits that simply can’t be overcome?
In at least one regard, thoroughness of hand washing, the answer seems to be yes. When even the cleanliest men were scored against the CDC’s guidelines—use hot water, scrub for 20 seconds, turn off the faucet with a towel—the “quality was uniformly bad.”
Ladies? Try Purell.