When a man takes a woman out on a date to an expensive restaurant and lavishes her with gifts, it might mean that he’s very wealthy or that he really likes her a lot.  Then again, there is also the distinct possibility that his behavior may simply mean that there just aren’t all that many women in town.

That’s right, new research, which took place at the University of Minnesota in Minneapolis, found that even just the idea that there is a lack of local women makes men act more impulsively, especially when it comes to finances.¹ (Don’t you just love the things people think of researching? And yes, the researchers were primarily men.) The researchers conducted several lab experiments to determine whether a scarcity of women would affect men’s spending.  In one trial, the volunteers were provided with news articles that discussed the higher ratio of men to women in their area.  The men were then interviewed about the amount of money they planned to put into savings monthly and the amount that they would borrow with credit cards.  Those who were informed that there were fewer women than men reported a 42 percent drop in what they would save and a whopping 84 percent increase in what they would be willing to borrow from credit cards.

In another portion of the experiment, the subjects were shown photos with a higher percentage of men, a higher percentage of women, or an equal number.  Afterward, the participants were given a choice of receiving $20 the next day or $30 in a month’s time.  The men who viewed photos with fewer women were much more likely to request their money right away.

All of these actions seemed to be subconscious behaviors, with no volunteer implying that the scarcity of women had anything to do with it.  What this really seems to mean is that we are much more similar to other species in the animal kingdom than we sometimes like to admit.  Out in the wild, male animals are always more competitive with each other when there are not many available females.  And it would seem that same principle holds true for humans, with immediate changes in the way we think and behave at the mere suggestion of a lack of women.

Besides the experiments with volunteers, the researchers also looked at data across the United States to get a sense of the behavior of a wider sampling of the population.  They determined the male to female ratio in more than 120 cities across the country and found that — just like in the lab — men who live in places where they outnumber the women tend to have more credit cards and higher overall debt.  In locations with larger proportions of men, the men carry several thousand more in debt on average than those who live near an abundance of women, even when those communities are in similar parts of the same state.

And women are not immune to the effects of their scarcity, either.  When women participating in the study were provided with information about a relative lack of females to males, they reported that men should spend more money while dating, whether it’s on evenings out, gifts, or the engagement ring they would expect.

After all, there have been numerous studies that ask women what makes a man attractive, and success usually ranks near the top.²  Could this be due to the biological imperative, with women unconsciously recognizing that success breeds testosterone, while testosterone breeds success, all of which leads to enhanced likelihood of successful baby-making?  And men recognize that they need to spend more money when women are scarce if they want to appear successful and have any chance of beginning a relationship with one of them. Or is it the fact that money is the new testosterone? That having money means a man is better able to provide a safe and comfortable “nest” for raising a family? Is Mark Zuckerberg the new Hercules?

As much as we may try to deny our animal side, vestiges of it are still definitely in existence.  So single men, if you are planning a move any time soon, do some research to find out the male to female ratio in your new town.  Because if the numbers are not in your favor, you may need to up your earning power just to get a date! And if you live in China or India, where there are no favorable ratios, you might want to move out of the country quickly — at least while spouse hunting.

¹ Griskevicius, Vladas;Tybur, Joshua M.;Ackerman, Joshua M.;Delton, Andrew W.;Robertson, Theresa E.;White, Andrew E. “The Financial Consequences of Too Many Men: Sex Ratio Effects on Savings, Borrowing, and Spending.” Journal of Personality and Social Psychology, Vol 102(1), Jan 2012, 69-80. (Accessed 16 Mar 2012.) <http://www.csom.umn.edu/assets/166362.pdf>.

² Singh, D. “Female judgment of male attractiveness and desirability for relationships: role of waist-to-hip ratio and financial status.” Journal of Personality and Social Psychology. Dec. 1995. Accessed 15 March 2012. <http://www.ncbi.nlm.nih.gov/pubmed/8531056>.