Toronto: Prejudice is a trait that might be rooted in sheer survival as our ancestors avoided outsiders who might have been carriers of disease or plague, reveals a study. Research shows that when people feel vulnerable to illness, they exhibit more bias towards stigmatized groups. But a new study suggests there might be a modern way to break that link.

'We thought if we could alleviate concerns about disease, we could also alleviate the prejudice that arises from them,' said Julie Y. Huang of the University of Toronto, the journal Psychological Science reported.

Huang conducted the study with Alexandra Sedlovskaya of Harvard University; Joshua M. Ackerman of the Massachusetts Institute of Technology; and Yale University's John A. Bargh.

The group found that the sense of security derived through measures such as vaccination and hand washing can reduce bias against out groups, from immigrants to the obese, according to a university statement.

The study is unique in uniting evolutionary psychology, social cognitive psychology and public health. It holds promise for reducing physical and social maladies at once.