The Trivers-Willard Effect for Educational Investment: Evidence from an African Sample

The Trivers-Willard hypothesis (TWH) states that individuals in good condition favor offspring of the sex that has a higher variance in reproductive value. Empirical studies with historical human populations suggest that the TWH might explain biased birth-ratios as well as biased parental investment in male or female offspring. However, empirical tests of the TWH in modern human populations are less conclusive. In this study, we investigate whether parental investment in education might be skewed according to the TWH in an African sample ( N = 314) that includes students from 8 different countries. The data show that male students who rate their family’s wealth high tend to report more parental involvement in their own education, whereas the opposite is true for female students. This pattern is in accordance with the TWH for parental investment. The results support the validity of evolutionary explanations of behavioral bias in the context of parental investment in offspring education.