24/02/2012 15:19 GMT | Updated 25/04/2012 10:12 BST

How A Man's Immune System Boosts His Sex Appeal

The reason why so many women are attracted to 'masculine' men may have less to do with their rugged good looks and more to do with their powerful immune systems, a study has found.

An ability to stave off man-flu might not sound like the hottest trait in a man but in evolutionary terms it does make sense, as women are inherently attracted to men who could provide their children with the strongest possible immune system.

The researchers at Abertay University studied 74 Latvian men in their early twenties, measuring their immune response to a hepatitis vaccine as well as the concentration of testosterone and cortisol in their blood.

Latvian women, also in their twenties, were asked to rate the facial attractiveness of the subjects using a 10-point scale.

Men with high levels of testosterone had a strong immune system and were ranked as more attractive.

Men with low levels of testosterone had weaker immune systems and higher concentrations of the stress hormone, cortisol, which may have inhibited their immune responses.

This also suggests that stressed-out men may be less attractive to women.

Researcher Dr Fhionna R Moore, Ph.D. said: "It's always been an assumption that the healthier you are, the more attractive you are but it has never really been proved before.

"We found there was a really strong connection between how well these men reacted to the jab, and how attractive women thought they were.

"We believe it's because inherently women seek for their offspring to inherit the healthiest immune systems."

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