Ruthless women have extra testosterone, scientists show

Tough women bosses break the glass ceiling with help from male hormone

They have long been portrayed as boardroom battleaxes – ruthless women who will stop at nothing to achieve success in business. Now a controversial scientific study has suggested that there might be a chemical reason for the stereotype.

Women with higher levels of testosterone are more likely to pursue risky careers in business and finance, according to US scientists. They say it demonstrates just how important the hormone is in defining the differences between the genders.

While earlier studies have shown that people with high testosterone levels are typically more competitive and dominant, this is the first time the hormone has been proven to have an impact on career choice.

The research, published yesterday in the US journal Proceedings Of The National Academy Of Sciences, found that women with high testosterone levels had a greater appetite for risk but the same was not true among men. However, men and women with similar levels of the hormone were found to be equally likely to take risks. Individuals with the highest levels of testosterone also opted for riskier financial careers after graduation.

"This is the first study showing that gender differences in financial risk aversion have a biological basis, and that differences in testosterone levels between individuals can affect important aspects of economic behaviour and career decisions," said Dario Maestripieri, one of the scientists who carried out the study.

Researchers took saliva samples from about 500 MBA students of both genders at the University of Chicago's business school and used them to measure testosterone levels.

They also took into account indicators such as finger length, which can point to higher levels of the hormone. Women with higher levels of testosterone tend to have longer ring fingers than index fingers. In the study, just 36 per cent of the female students chose high-risk financial careers such as investment banking or trading, compared to 57 per cent of male students.

"In general, women are more risk averse than men when it comes to making important financial decisions, which in turn can affect their career choices," said Paola Sapienza, another of the study's authors.

The MBA students were asked to play a computer game, during which they answered questions and were then asked to choose between playing it safe and accepting a guaranteed amount of cash, or gambling to win a potentially higher payout.

"This study has significant implications for how the effects of testosterone could impact on actual risk-taking in financial markets, because many of these students will go on to become major players in the financial world," said Luigi Zingales, a third scientist. Women with high testosterone levels and a habit of taking risks are also likely to have higher sex drives than their peers, as the hormone is also known to govern libido in both sexes.

However, Professor Alex Haslam, of the University of Exeter, who has carried out research into the boardroom barriers facing women, said it was likely that many of the female MBA students who took part in the study would already have had increased testosterone levels because of their high-pressure careers.

"I think if you work for a bank you're more likely to have high testosterone levels, rather than the other way around," he said. "I wouldn't say that women who are more 'masculine' are drawn towards more traditionally masculine professions – actually, if you find yourself in a masculine profession, you're more likely to develop these attributes naturally."