In fall quarter 2007, researchers posted messages in the bathrooms of two DU undergraduate residence halls. The messages said things like, “Poo on you, wash your hands” or “You just peed, wash your hands,” and contained vivid graphics and photos. The messages resulted in increased handwashing among females by 26 percent and among males by 8 percent.
Most human cognition is implicit, and we’re really not as amenable to rational appeals we like to think we are. Remember this research?:
We examined the effect of an image of a pair of eyes on contributions to an honesty box used to collect money for drinks in a university coffee room. People paid nearly three times as much for their drinks when eyes were displayed rather than a control image. This finding provides the first evidence from a naturalistic setting of the importance of cues of being watched, and hence reputational concerns, on human cooperative behaviour.