SCIENCE, 323, 7 May 2010, p.709 Washing Away Post-Decisional Dissonance Spike W. S. Lee & Norbert Schwarz 1 Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA. Contact information: Spike W.S. Lee: spikelee@umich.edu ; ph. 734-926-9691 http://sitemaker.umich.edu/wing.sing.lee/home Norbert Schwarz: norbert.schwarz@umich.edu ; ph. 734-272-4677 http://sitemaker.umich.edu/norbert.schwarz/home One-sentence summary: Washing one’s hands after making a choice eliminates post-decisional dissonance effects, suggesting that hand-washing psychologically removes traces of the past, including concerns about past decisions. Online abstract: After choosing between two alternatives, people perceive the chosen alternative as more attractive and the rejected alternative as less attractive. This postdecisional dissonance effect was eliminated by cleaning one’s hands. Going beyond prior purification effects in the moral domain, physical cleansing seems to more generally remove past concerns, resulting in a metaphorical “clean slate” effect.