Oestrogen works for women the way testosterone does for men

Collaboration by American and German scientists has revealed that the sex hormone oestrogen increases a women's competitiveness.

The researchers from the University of Michigan and the Friedrich-Alexander University in Erlangen, have revealed that oestrogen fuels a desire for power, with single women and those who are not on the pill particularly vulnerable to the influence of the hormone.

Recent research from Cambridge University showed that male money traders were financially more successful when their testosterone levels were high, and the German team were curious as to how levels of oestradiol, which is a form of oestrogen affected power-motivated women.

Researcher Steven Stanton began the study with a group of 49 young women who were shown a picture and asked to write a short story about a theme related to power.

Mr Stanton says the more power themes that someone wrote about, the more power-motivated they were considered to be.

The women then competed in pairs against each other in ten rounds of a rapid response computer game - saliva samples showed the most power-driven women had the highest levels of oestradiol.

When the women won a computer game their levels of oestradiol soared but plummeted when they lost, and the elevated levels of estradiol were still present the day after the contest.

The finding mirrored the role of the sex hormone testosterone in driving feelings of dominance in men.

Mr Stanton, an expert in the psychology of motivation says the saliva samples taken during and after the contest revealed a clear correlation between hormones and emotions and Dr. Schultheiss says the findings parallel those observed for power motivation and testosterone in men.

Mr Stanton says in those women not interested in power the oestradiol behaved very differently, if they won, their oestrogen went down - if they lost, their oestrogen went up a little bit.

The researchers now hope to test women past the menopause, when the levels of oestrogen are lower, and also to test men and women as they compete against one another.

The research is published in the journal Hormones and Behavior reports.