Sexually antagonistic selection on educational attainment and body size in Estonian children

Natural selection is a key mechanism of evolution, which results from the differential reproduction of phenotypes. We describe fecundity selection at different parity transitions on 15 anthropometric traits and educational attainment in Estonian children, who were born between 1938 and 1962 and measured at around 13 years of age (Juhan Aul’s database). The sample sizes reach up to 7000 in boys and 10 000 in girls. The direction of selection on educational attainment and bodily traits was sexually antagonistic, and it occurred via different parity transitions in boys and girls. Compared to boys with primary education, obtaining tertiary education was associated with 3.5 times and secondary education two times higher odds of becoming a father. Transition to motherhood was not related to educational attainment, while education above primary was associated with lower odds (OR = 0.5 – 0.7) to progression to parities above one and two. Selection on anthropometric traits occurred almost exclusively via childlessness in boys, while among the girls, most of the traits that were associated with becoming a mother were additionally associated with a transition from one child to higher parities. Male (but not female) fitness was thus primarily determined by traits related to mating success. Selection favoured stronger and larger boys and smaller girls. Selection on girls favoured some traits that associate with perceived femininity while other feminine traits were selected against.

This record includes the data and R code to reproduce  the statistical analyses the results are based on.