Skip to main content
Dryad logo

Data from: Are human natal sex ratio differences across the world adaptive? A test of Fisher’s principle

Citation

Douhard, Mathieu; Dray, Stéphane (2021), Data from: Are human natal sex ratio differences across the world adaptive? A test of Fisher’s principle, Dryad, Dataset, https://doi.org/10.5061/dryad.kkwh70s3g

Abstract

Fisher’s principle states that natural selection favours an equal number of male and female births at the population level, unless there are sex differences in rearing costs or sex differences in mortality before the end of the period of parental investment. Sex differences in rearing costs should be more pronounced in low- than in high-resource settings. We, therefore, examined whether human development index and sex differences in child mortality contribute to the natural variation in human sex ratio at birth across the globe. As predicted by Fisher’s principle, the proportion of male births increased with both increasing male-biased childhood mortality and level of development of each country. However, these relationships were absent after accounting for spatial autocorrelation in the residuals, which our inference is conditioned on. This work shows how the failure to account for residual spatial autocorrelation can lead to incorrect conclusions regarding support for predictions from sex allocation theory.

Usage Notes

The txt files included here allow to replicate all study findings reported in the article. Analysis code (R script) is available in an R Markdown document (Supplement.Rmd). This document allows to generate the electronic supplementary file.