Obsessive tidiness could be the root cause of racism, a new study has claimed.
Researchers at Yale University discovered a link between a person's reactions to geometric quirks - such as an untidy bookshelf - and discriminatory tendencies.
During the study, scientists found a clear connection between how people felt about messy geometric patterns and their feelings on 'out-groups' including ethnic minorities, obese people, and people with skin conditions.
Leading social scientist Anton Gollwitzer and his colleagues tested the responses of American and Chinese children to interrupted patterns - such as a pizza with a triangle cut out of its centre - in a bid to make the link.
Carol Sigelman, professor of psychology at George Washington University, said of the study: "The link between social prejudice and pattern deviancy aversion might be 'baked into human nature' during childhood.
"Children as young as three turn out to be eager conformists who detect social norms, and stand ready to squeal on and punish norm violators.
"The ingredients of prejudice are in place very early in life. Humans may start out all too ready to judge one another, but how do some forms of human difference become more stigmatising than others, and how do some human perceivers become more prone to stigmatise?
"The research provides a simple potential explanation for why some people feel uneasy around and dislike people who deviate from societal norms."
The findings have been published in the Nature Human Behaviour academic journal.
