A controversial study states that the real motive for women to pursue careers is because they fear they are too unattractive to get married.
The research team, made up of three women and two men, said that when the availability of men is scarce, 'women are more likely to choose briefcase over baby'.
And the plainer a woman is, they claim, the more she is driven to succeed in the workplace.
Central to their argument was the idea that women have evolved to become homemakers and men, providers.
The team said this means that when men are scarce in a particular area, women, and particularly less attractive ladies, may decide they need to provide for themselves with a well-paid career.
The researchers carried out several experiments to come up with their startling argument.
The first looked at the number of eligible men in an area, which they called the 'operational sex ratio'.
After collecting data from across the U.S., they found that as the number of eligible men in a state decreased, the proportion of women in highly paid careers rose.
In addition, the women who became mothers in those states did so at an older age and had fewer children.
To prove that lack of men was behind the trend, the researchers then carried out various practical experiments.
These involved showing women newspaper articles or photos that gave different impressions of the sex ratio in an area and then quizzing them about which was more important - work or family. When they were led to believe that men were scarce, they were more likely to prioritise career over family.
However, when questioned, the women didn't believe the shortage of men would lead to more job openings for women.
Instead they thought there would be more competition to find a husband.
The final experiment tested the researchers' suspicion that less attractive women would be more interested in careers because they might find it difficult to secure a partner.
The 87 young women were given mocked-up newspaper articles describing the sex ratio in nearby university campuses and were asked about their views on family and career.
They were also asked how attractive they believed themselves to be to men.
Those women who saw themselves as being less desirable than average were highly likely to be career-orientated.
"Does the ratio of men to women in a local population influence women's career aspirations? Real-world archival data and a series of laboratory experiments suggest that the answer is yes," the Daily Mail quoted Kristina Durante, researcher, from the University of Texas at San Antonio, as saying.
In Britain, the number of young men is slightly more than women.
However, females aged 36 or older are in the majority. And at universities, female undergraduates now outnumber males.
Economist Ruth Lea said that on a basic level it made sense that women would have to support themselves if the odds of being supported were low.
However, she said many factors, from aptitude to ambition, played a much larger part in a woman's career path.
"I often find that women who were getting on well in the workplace will in private conversations with me, express wanting to settle down," Pam Spurr, agony aunt, said.
The study, which was carried out by U.S. and Dutch researchers, is published in the Journal of Personality and Social Psychology.