Dickerson et al., 1992: Prompting hypocritical feelings about length of showers reduced shower time among female swimmers
Female swimmers exiting a pool were led to feel hypocritical about the length of their showers by both (a) agreeing to help out with campus conservation efforts by signing their name to a flyer saying “Please conserver water. Take shorter showers,” and (b) responding to survey items asking, for instance, “When you take showers, do you ALWAYS make them as short as possible, or do you sometimes linger longer than necessary?” This reduced shower time relative to a condition in which swimmers did neither (a) nor (b). Swimmers who did either (a) or (b) did not differ from either the hypocrisy or the control group. Additionally, whereas 35% of swimmers in the control group turned off the shower while shampooing or soaping up, 70% of those who did (a), (b), or both did.