If something looks dirty and disgusting, we typically assume it's contaminated in some way; when something is white, however, we are more likely to assume that it's clean and pure.
Research has shown that people from many different cultures hold this association between lightness and purity, which may explain why we prefer white teeth, white operating rooms, and white porcelain bathroom fixtures, the journal Psychological Science, reported.
"In the psychology of purity, even the slightest deviation from a pure state (whiteness) is an unacceptable blemish," observes psychological scientist Gary Sherman from the Harvard University's Kennedy School of Government and co-authors.
Sherman and co-authors investigated this hypothesis in three studies, in which they tested participants' ability to make subtle grey-scale discriminations in both ends of the light spectrum, according to a Harvard university statement.
Together, the three studies provide evidence for an interactive relationship between disgust and perceptual sensitivity that may ultimately help us detect and avoid the germs, toxins, and other contaminants around us.
This research was co-authored by Gerald Clore of the University of Virginia and Jonathan Haidt, who is now at the New York University Stern School of Business.
