Mr. G. Stulp: Sex, stature and status. Natural selection on height in contemporary human populations

PhD ceremony: Mr. G. Stulp, 11.00 uur, Academiegebouw, Broerstraat 5, Groningen

Disstertation: Sex, stature and status. Natural selection on height in contemporary human populations

Promotor(s): prof. A.P. Buunk, prof. S. Verhulst

Faculty: Behavioural and Social Sciences

As an upright walking mammal, height is perhaps our most conspicuous feature. Height is a highly variable trait, both within and between populations, has a high heritability, and influences the manner in which people behave and are treated in society. It is therefore possible that natural selection acts on this variation in height and, in this thesis, I investigated whether this was the case.

I first examined sexual selection on height, demonstrating that taller individuals have higher social status and increased dominance, that there are height preferences for potential mating partners, that these preferences influence choice in a speed-dating context, and that height preference and choice influence actual pair formation.

Having established a role for height in intra- and inter-sexual selection, I considered other ways in which height contributes to biological fitness, and how this differs between the sexes. I demonstrated that shorter women and women with partners much taller than themselves are at greater risk for a Caesarean section, and therefore face greater mortality risks. I furthermore showed that shorter women have more children than taller women, despite higher child mortality, whereas average height men have more children than both shorter and taller men. Due to these differential selection pressures, shorter families achieve higher reproductive success through the female line, whereas average height families achieve greater reproductive success through the male line.

In summary, there is natural selection on height in contemporary human populations.