Wash your hands, you'll feel better

| Comments (0) | Misc
Public health types are always stressing how important hand washing is for preventing the spread of disease. Somewhat surprisingly, it seems to have other benefits as well. I somehow missed it but in 2006, Zhong and Liljenquist reported that handwashing seems to act as a counter to feelings of moral wrongness

Washing Away Your Sins: Threatened Morality and Physical Cleansing Chen-Bo Zhong1* and Katie Liljenquist2

Physical cleansing has been a focal element in religious ceremonies for thousands of years. The prevalence of this practice suggests a psychological association between bodily purity and moral purity. In three studies, we explored what we call the "Macbeth effect"--that is, a threat to one's moral purity induces the need to cleanse oneself. This effect revealed itself through an increased mental accessibility of cleansing-related concepts, a greater desire for cleansing products, and a greater likelihood of taking antiseptic wipes. Furthermore, we showed that physical cleansing alleviates the upsetting consequences of unethical behavior and reduces threats to one's moral self-image. Daily hygiene routines such as washing hands, as simple and benign as they might seem, can deliver a powerful antidote to threatened morality, enabling people to truly wash away their sins.

In a recent issue of Science, Lee and Schwarz report that handwashing after choice tasks reduces post-choice assessments of differences between the choices:

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.

The first of these studies seems straightforward but the second less so. As I read it, Lee and Schwarz's interpretation of the results is that people asked to select one of two alternatives when they are less indifferent feel the need to adjust their preferences to justify the choice. Handwashing reduces that reasessment process:

These findings indicate 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. This observation is not captured by the purity-morality metaphor and highlights the need for a better understanding of the processes that mediate the psychological impact of physical cleansing. To further constrain the range of plausible candidate explanations, future research may test whether the observed "clean slate" effect is limited to past acts that may threaten one's self-view (e.g., moral transgressions and potentially poor choices) or also extends to past behaviors with positive implications.

Even more future research might ask whether handwashing impacts other non self-image type issues. E.g., what's the impact on memory, reliability of past assessments, etc.? I also noticed that in the second paper, the initial variance between the two choices (pre-washing) was larger, so I wonder if this might have had an impact somehow. Regardless, I'll be stocking up on hand soap.

Leave a comment