Why brown-eyed girls are twice as likely to feel blue when its wintry

WoMeN with brown eyes are more than twice as likely to feel down when the weather is bad, a study has found.

Researchers found those with dark eyes were at twice the risk of seasonal affective disorder, also known as SAD, than men with blue eyes.

This is because dark eyes let in less sunlight during shorter days of the year, affecting the production of ‘happy hormone’ serotonin.

Lead author Professor Lance Workman, of the University of South Wales, which carried out the research, said: ‘If you are a woman with brown eyes, based on our study, you are more than twice as likely to suffer from SAD as a blue-eyed man.

‘We suggest that blue eyes may have developed in european people as a genetic mutation 10,000 years ago to help protect them from the energy and depressive effects of living so far from the equator during the winter months.’

The research – presented at the British Psychological Society conference – that found blue-eyed people were protected from SAD came from a study of 175 people in Britain and Cyprus, while researchers also carried out a survey of 2,031 Britons which found women were 40 per cent more likely to suffer SAD.

Women may suffer more for evolutionary reasons allowing them to conserve energy during winter to better care for children.