The Influence of Sex Ratio on Saving, Borrowing, and Spending: An Experimental Approach

Abstract

The ratio of males to females in a population is known to be an important factor in mating and parenting behavior in animals. Sex ratio has pervasive effects in humans that go beyond typical mating behaviors, such as by influencing common economic decisions. Two experiments examined how perceived male-biased versus female-biased sex ratios influence financial decisions regarding saving, borrowing, and spending. Male-biased ratios led men to discount the future—to desire access to immediate monetary resources at the expense of larger, later returns. Male-biased ratios also decreased men’s financial saving for the future, while increasing willingness to incur debt for immediate expenditures. These findings are the first to demonstrate experimentally that sex ratio influences human decision-making in ways consistent with evolutionary biological theory, opening the possibility for uncovering how sex ratio might influence myriad human behaviors.