For men, there was a curvilinear effect of height on reproductive success, with taller than average men producing both a larger number of ever born children and more surviving children (table 1 and figure 1a). There was no effect of height on child mortality nor on the proportion of surviving offspring (table 1). Controlling for education, income and health slightly attenuated the effect of height on reproductive success, suggesting that the relationship was partially mediated by these factors (table 1, figure 1a).
Shorter men were also likely to have lower fertility because of a reduced likelihood of currently being in a relationship and ever having a partner (table 1 and figure 1c); controlling for these mate choice variables in both cases decreased the effect size of height on fertility, suggesting partial mediation (electronic supplementary material, table S7). Taller men were also more likely to have a second child compared with shorter men (table 1), however, which indicates that relationship status was not the sole cause of higher fertility among taller men.
Taller men started their current relationships at a later age than both average height and shorter men (the latter starting their relationships at a later age than average height men; figure 1e), which might account for the levelling-off of fertility for very tall men. This is countered, however, by the positive relationship between height and the number of children produced within a man’s current relationship (figure 1a). Indeed, very tall men were likely to do better reproductively than men of only above average height within their current relationship. It is also notable that taller men achieve their higher reproductive success despite a later age at first birth (figure 1e)
