The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 19 No. 3 • April 2016


Cleanse Your Body
Wash Your Sins Away
The evidence of priming studies suggests that reminding people of their mortality increases the appeal of authoritarian ideas, which may become reassuring in the context of the TERROR OF DEATH.

...merely thinking about stabbing a co-worker in the back leaves people more inclined to buy soap, disinfectant or detergent than batteries, juice, or candy bars. Feeling that one’s soul is stained appears to trigger a desire to CLEANSE one’s body, an impulse that has been dubbed the LADY MACBETH EFFECT. (emphasis added)

—from Daniel Kahneman,
Thinking Fast And Slow,
Farrah, Straus, and Giroux, 2011

DETERGERE, Latin for: to CLEANSE by rubbing. (So, you see, the Roman Empire didn’t fall, not entirely. Its language, LATIN, goes on and on. You did notice the similarity between DETERGERE and “detergent” of course.)

“Washing” and “cleansing” and “purification” and the like are almost ubiquitous in their occurrence in social contexts. “Wash your sins away,” “wash your mouth out with soap,” ethnic or political “purification,” “ethnic cleansing,” “cleanliness is next to godliness,” “washing your hands” of some problem, and the list goes on. Cleanliness, it seems, has a deeper meaning than just removing dirt.

For instance, a recent paper (Lee, 2010) describes how “[h]and washing removes more than dirt—it also removes the guilt of past misdeeds, weakens the urge to engage in compensatory [e.g. retaliatory] behavior and attenuates the impact of disgust on moral judgment.” The authors of the paper suggest that the “cleansing” that accompanies hand washing “may also reflect that washing more generally removes traces of the past by metaphorically wiping the slate clean.” The researchers here tested the hypothesis that hand washing might reduce a post-decisional dissonance effect (the uncomfortable feeling that you might have made the wrong decision).

In fact, that is just what they found. A group of 49 undergraduate students (quintessential research subjects!) examined 30 CD covers in a music store and ranked them by preference, then being offered by the researchers a choice of their fifth and sixth ranked CDs.

Then the students were asked to participate in a supposed consumer test of a soap, with some of them simply examining it and some of them actually washing their hands. They were again asked to rank order the CDs. It would have been expected that in the reassessment of the rank order, having received a particular CD would result in its moving up to a higher rank (as an example of “cognitive dissonance”). However, what was ACTUALLY found was that the students who had washed their hands did not increase the rank order for the CD they received (unlike the students who only examined the soap). Thus, the hand washing did in fact “cleanse” the mind of the need to rationalize that the CD they received was really better than they had first thought.

Voting for the lesser of two evils is a classic example of how a decision sure to create dissonance may be “remedied” by imagining that the lesser of the evils was better than you might have thought at first. We wonder whether making it possible for individuals to wash their hands at the polling station might leave people in a less agitated mood. But then, again, perhaps they should be if they have truly voted for somebody evil.


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


The book (Thinking Fast And Slow) from which the quote at the start of this article was taken discussed how washing could be connected to moral “cleansing.” The author described an experiment in which people were induced to “lie” to a fictitious person on the telephone or by email. In doing so, it was likely expected to cause these “liars” (though they hadn’t actually LIED, they only simulated a lie) to nevertheless feel tainted and to attempt to “cleanse” themselves of their “moral lapse.” In fact, as the results showed, “people who had lied on the phone preferred MOUTHWASH over soap, and those who had lied in e-mail preferred SOAP to mouthwash.” (This preference referred to whether or not these individuals would buy mouthwash or soap, as assessed by a subsequent test.)

The idea that the participants would be highly motivated to “clean out their mouths” was substantiated. Parents used to admonish their children to “wash out their mouths” (we don’t know if they still do) after they had said or done something the parents considered wrong.


In another paper (Schnall, 2010), researchers discuss how cleanliness can reduce the severity of moral judgments by toning down the desire to punish “wrongdoers.”

In this experiment, subjects were “primed” by hearing words that connote cleanliness whereas controls heard neutral words. After being “primed,” the participants were asked to rate six moral dilemmas, such as switching tracks so a train ran over one workman rather than five, killing (and eating) a terminally ill plane crash survivor to avoid dying of starvation, lying on a resume, etc. They were asked to rate their mood following these judgments. The results showed that the moral judgments of the hypothetical individuals making the decisions in the moral dilemmas was less severe when they had been “primed” with words connnoting cleanliness. The authors suggest that the thoughts of physical cleansing produced a sort of moral cleansing that reduced feelings of disgust associated with the decisions.


Schnall et al. With a clean conscience: cleanliness reduces the severity of moral judgments. Psychol Sci. 19:1219-22 (2010).

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