Men have for long been seen as judging women on looks alone, but a study has now shown that the increase in male sex hormone level was not influenced by the perceived attractiveness of the women.

The research, published in the journal Hormones and Behaviour, suggested that the levels of their testosterone surged to the same extent whether they were talking to an attractive woman or someone they may not fancy at all.

The research involving 63 male students aged 21 to 25 found that their testosterone levels increased by an average of around eight per cent after just 5 minutes exposure to a stranger from the opposite sex and in some cases to women they not find particularly attractive.

“We found a testosterone increase after only five minutes of exposure to a woman. Our results suggest that the increase in testosterone levels that we found, may be an automatic male response that activates receptors in organs and the nervous system to prepare the human body for mate attraction,” said Leander van der Meij, who led the study at the University of Groningen in Holland.

He said with the increase in testosterone levels males tend to display more dominant behaviour.

“They talk more with their hands, there is more eye contact, their posture is more upright, and they are more likely to tell stories designed to impress the woman. We known that women can be attracted by these kinds of things. All this, we believe, may be fuelled by the rise in testosterone that we have found,” said der Meij.

Aggressive males showed greater rise in testosterone levels, an idea supported by research that men who exhibit more dominant-like behaviour tend to make more frequent successful contact with females.