Science, via Ars Technica. My interest in this stuff relates generally to how we strange creatures make decisions—voting, say.
According to an unusual study, washing your hands is not only healthy, but it may also put your mind at ease about recent past decisions. A couple of researchers at the University of Michigan conducted a study asking students to choose between two objects out of several they had ranked. When students washed their hands after making the choice, they seemed to experience less cognitive dissonance, while students who did not wash their hands behaved as if they needed to justify their choices to themselves.
People often try to justify choosing one thing, such what to eat, over another by convincing themselves that their choice is superior, even though both items seemed equally good a few seconds ago. This is our way of dispelling the cognitive dissonance choosing creates; if we don’t do this, we tend to fret about whether we decided correctly. A couple of researchers decided to test how this dissonance might be affected by the act of washing, which is sometimes linked with moral self-judgment, but hasn’t been tested much in relation to other psychological processes.
They set some college students about the task of choosing ten CDs for themselves out of a set of 30, and then ranking them in order of preference. For participating, students were offered a gift of their fifth- or sixth-choice CD. Next, the students were split in two groups— one group washed their hands, and the other just evaluated liquid soap packaging.
When the two groups re-ranked their ten CDs, students that did not wash their hands ranked the CD they chose higher, as if to indicate to themselves that they wanted that CD anyway. Students that did wash their hands, though, ranked their chosen CD about the same, showing that hand-washing somehow dispensed with the need to justify a choice.
The authors think this indicates that physical cleanliness may have a broader impact on individual psychology than previously thought—washing has been linked before to absolution of moral guilt, but less so to self-perception. The study was small and limited in scope, but if the link is real, we need hand wipes served with hot wings more than ever.