A better understanding of the bridge between personality traits and physical health can perhaps help clinicians improve intervention and prevention programmes, he said.

Researchers found that smoking accounted for about 25 percent to 40 percent of the association between high neuroticism and mortality.

The other 60 percent is unexplained, but possibly attributed to biological factors or other environmental issues that neurotic individuals experience, Mroczek said.

Researchers analysed data of 1,788 men and their smoking behaviour and personality traits over a 30-year period from 1975 to 2005.

These findings were published in the latest issue of the Journal of Research in Personality.