Testosterone is not just a macho hormone

The male hormone testosterone does not only lead to macho behaviour and aggression. Men who make a lot of extra testosterone after a match against another man subsequently flirt more when they meet an unknown woman. This has been revealed by recently published research by psychologist Leander van der Meij, who will be awarded a PhD by the University of Groningen on 12 January 2012.

Testosterone is known to play an important role in competitiveness between men. It is also assumed that it is important when initiating sexual relationships. The exact relationship between competitiveness and pairing is, however, unknown. Van der Meij conducted an experiment to try to chart this more precisely. He had 84 young men compete one on one against each other in a knowledge quiz. During the competition the men produced significantly more testosterone – saliva samples from after participation in the quiz contained over 16 percent more testosterone than samples from before the quiz.

Increased flirting

After the quiz, a meeting was staged with a young woman or man. The men who had a greater increase in testosterone levels during the competition flirted more when they met a woman, the PhD student has determined. They asked more questions, were more open about themselves, made more eye contact and smiled more. Van der Meij: ‘Testosterone is often associated with macho behaviour and aggressiveness. My research shows that, depending on the context, it can also lead to positive social behaviour – testosterone prepares men for pairing.’ The PhD student does, however, present his conclusions with a few caveats. There is still the question of what comes first, the desire for a woman or increased testosterone levels. After all, it’s perfectly possible that testosterone levels increase more sharply when a man has a greater desire for a woman.

Woman around – testosterone increases

Van der Meij also demonstrates in his thesis that the testosterone levels of men shoot up when there’s a woman around. This phenomenon is most clearly observable in men with an aggressive, dominant personality. This research also revealed that aggressive, dominant men, men who had had no sexual contact for a month or more, or who did not have a permanent relationship automatically had higher testosterone levels than the other men. An increase in testosterone levels not only increases the motivation to attract partners, according to Van der Meij, but probably also leads to behaviour that women could find attractive.

The more beautiful the woman, the higher the stress hormone levels

With men, the cortisol levels also climb when a woman is present, Van der Meij has established. This was revealed by a different experiment where men had to wait for five minutes with a woman or man they had not met before. After this contact period, the men assessed the attractiveness of the person who had kept them company. This revealed that the cortisol levels increased in relation to the attractiveness of the woman. Cortisol is mainly known as a stress hormone. A chronically high cortisol level can be bad for your health. Van der Meij: ‘However, the activating effect of cortisol, which makes extra energy available in the body, could help when flirting.’

Curriculum Vitae

Leander van der Meij (Groningen, 1982) studied psychology in Groningen and conducted his PhD research at the department of Social Psychology at the University of Groningen and the department of social neurosciences of the University of Valencia, Spain. His supervisors were Prof. A.P. Buunk and Prof. A. Salvador. The research was partly financed by the Generalitat Valenciana and the KNAW. The title of his thesis is ‘When a boy meets a girl: the role of hormones in social situations relevant to male mating’. Van der Meij will continue his research as a postdoc at VU University Amsterdam.

Note for the press

Contact: Leander van der Meij: e-mail: l.van.der.meij vu.nl