Norbert Schwarz and Spike Lee (no relation to the film maker) from the University of Michigan have found that people have a subconscious desire to cleanse themselves when they perform a psychologically dirty act, such as lying. Not only that, but the specific area of their bodies they wish to clean depends on the type of lie.
The cognitive psychologists had a group of volunteers play act the following scenario: They were to pretend that they were lawyers hoping for a promotion in a large law firm. They had just found the essential document that a colleague needs to get the same promotion. If they tell the colleague they have his document, he’ll recover it and get the promotion instead of them. The volunteers were instructed to contact their competitor, either by email or by phone, and either lie or tell the truth about finding the document.
After this exercise, the volunteers were given the seemingly unrelated task of evaluating a variety of products, among which were both mouthwash and hand sanitizers. The one quarter of participants who had lied by phone rated the mouthwash very highly and were willing to pay a premium for it. The email liars felt the same way about hand sanitizer. The half who had told the truth did not feel any particular affinity to either product.
This study shows how 'concrete' the metaphorical links are between abstract and concrete domains of life. Not only do people want to clean after a dirty deed, they want to clean the specific body part involved.