This study investigates the relationship between historical utilization of the plow and modern sex ratios. The authors argue that in societies without the plow subsistence is generally egalitarian with both men and women contributing. However, the use of the plow requires more physical strength which, they argue, leads to a preference for boys and, thus, men. Therefore, in cultures that use the plow, this is reflected in male-biased sex ratios which are negotiated by way of practices like sex-selective abortions, infanticide, and/or differential access to resources based on sex.

The researchers examine Boserup's (1970) theory that variation in traditional agricultural practices shape gender roles by examining the relationship between historical plough use and contemporary fertility rates and preferential attitudes towards fertility. Contrary to expectation, tests show a negative relationship between plough use and both of these variables. The authors theorize that since children are less capable of performing the intensive labor required by plough agriculture compared to hoe agriculture, adoption of the plough deincentivized increased fertility and reduced its value among agriculturalists.