According to Kai Kaspar at University of Osnabrueck who suggests that the soap and water not only cleans your hands but washes off the psychological need to try harder to make you feel competent again.
Throwing out the motivational baby with the bath water? Or is it more than that? I wonder if it makes you forgot what you just did which means you don’t learn from your error; you go back a step to start again instead.
The report on the study (HBR September 2012) also mentions that hand washing lessens a person’s guilt after immoral behaviour. A touch of the Pontius Pilate maybe?
Strange how many expressions we use about washing or cleansing eg making a clean break, washing your hands of something, wipe the slate clean. There is something ritualistic about washing hands and maybe it taps into some unconscious belief we have.
There is also a genetic component to washing and cleaning believe it or not. Compulsive washing is one symptom of OCD, which can be a dysfunctional way to deal with anxiety.