The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 13 No. 4 • August 2010

Reducing Uncertainty in Decisionmaking By Hand Washing
(We Aren’t Making This Up, Honest ...)

Cognitive dissonance is a state of lingering uncertainty about a decision that has been made where one had to choose one of two or more choices. This has been studied extensively in the context of experimental setups where people are given the choice of two similarly attractive options, such as say a vacation to two places you’d love to visit where you have to choose one. The result of a decision is cognitive dissonance as there is generally some lingering doubt about whether you should have made the other attractive choice. Studies have shown that the way people handle this cognitive dissonance is to downgrade the desirability of the rejected choice following the decision not to choose it.1 This mental manipulation justifies the choice made and eliminates the unpleasant lingering uncertainty.

Researchers studied the possibility that hand washing could reduce cognitive dissonance in the subjects of their experiment.1 The participants were 40 undergraduates who thought they were involved in a consumer survey. They were asked to pick out 10 CD covers that they would like to own out of a selection of 30. Then they were asked to rank order the CDs they chose as to preference. The subjects were next given the opportunity to choose either of their choice number 5 or 6 as a gift for participating in the “survey.” That was followed by having the subjects “evaluate” a liquid soap, either by examining it or by washing their hands with it. After all this, the researchers had the subjects again rank the top 10 CDs, “allegedly because the sponsor wanted to know what people think about the CDs after leaving the store.”1 The results showed that the people who just examined the soap increased their preference for the chosen CD over the rejected alternative whereas the people who washed their hands did not, suggesting that cognitive dissonance had been reduced by hand washing. The authors1 then describe another choice experiment in the literature that included hand washing with an antiseptic wipe and which replicated the findings of the first described experiment.

The authors ponder these results. They suggest that “the psychological impact of physical cleansing extends beyond the moral domain. Much as washing can cleanse us from traces of past immoral behavior, it can also cleanse us from traces of past decisions, reducing the need to justify them.” However, they admit that there is a need for an understanding of the processes that mediate this purported mental “cleansing” (the psychological impact) of physical cleansing.

Sounds like something your marketing department would like to know!


  1. Lee and Schwartz. Washing away postdecisional dissonance. Science 328:709 (2010).

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