SAN ANTONIO - Men turn into big spenders when women are scarce. Researchers at the University of Minnesota found
that when men think the female population is scarce, they compete by saving less, borrowing more and being more impulsive.
"What we see in other animals is that when females are scarce, males become more competitive. They compete more for access to mates," says Vladas Griskevicius, an assistant professor of marketing at the Carlson School and lead author of the study. "How do humans compete for access to mates? What you find across cultures is that men often do it through money, through status and through products."
The researchers found that men would borrow 84 percent more each month and save 42 percent less. They also were more likely to take $20 now, over waiting a month for $30. That happened when they were shown pictures that had more men in them than women.
The study also found real-life evidence of this behavior. In Columbus, Ga., where there are 1.18 single men for every single woman, the average consumer debt was $3,479 higher than it was 100 miles away in Macon, Ga., where there were 0.78 single men for every woman.
According to Griskevicius, participants were unaware that sex ratios were having any effect on their behavior. Merely seeing more men than women automatically led men to simply be more impulsive and want to save less while borrowing more to spend on immediate purchases.
Sex ratios don't affect women's financial decisions, but they do affect their expectations of how much men should spend on them, the study found. After reading an article stating that men outnumbered them, women expected men to spend more on dinners, Valentine's Day gifts and engagement rings.
In 2010, there were eight unmarried men for every nine unmarried women in the USA, the Census Bureau says. For unmarried Americans age 15 to 49, though, there were 11 unmarried men for every 10 unmarried women.