Women who lust over handsome stars such as Brad Pitt may really be craving their immune systems. Their chiselled faces and toned bodies are a sign that they have more antibodies to fight off diseases, and women who fancy them want to pass these genes on to their own children, according to research by Abertay University in Scotland.
The findings suggest that women might be more attracted to men with high levels of the sex hormone testosterone because they have a healthier immune system.
Sexual characteristics in male faces are testosterone-dependent, but how the sex hormone affects immune function is unclear.
The researchers measured the immune responses of 74 Latvian men in their early twenties to a hepatitis vaccine, and determined the blood concentrations of testosterone and cortisol. They then asked Latvian women of a similar age to rank the participants by facial attractiveness on a 10 point scale.
The team found that men with a strong immune response had high levels of testosterone and were perceived as more attractive. Men with low levels of testosterone tended to have higher concentrations of cortisol, suggesting that their immune responses might have been inhibited by the stress hormone.