Why are Dutch people so tall? An article in The Guardian about research – conducted in Groningen – to answer that question has been shared over 2,300 times on Facebook. That research was done by Gert Stulp, who now works at the London School of Hygiene & Tropical Diseases. The answer seems to be that a combination of environmental factors – diet, good health care and social equality – and natural selection have favored taller heights.

Stulp graduated from the RUG in 2013 with a PhD about the ‘evolutionary relevance of human height’, his personnel page at the British university’s website reads. Part of his expertise is the relationship between height and mate choice.

The average Dutch male is 184 centimetres – six feet – tall, and Dutch women aren’t far behind: they’re typically 171 centimetres – five feet and seven inches – tall. That is a dramatic increase over time: ‘the average male height in the Netherlands has gained 20 cm (eight inches) in the last 150 years’, according to The Guardian. In comparison, American male height has only risen by six centimetres.

LifeLines

‘We saw that across 35 years, height was reasonably consistently related to the number of children people had’, Stulp says. Above-average height men had more children, but for women, average height appeared to correlate with more offspring. ‘Since height is highly heritable – taller parents tend to have taller offspring – natural selection may drive the Dutch population towards taller heights.’

Stulp, who is 200 centimetres tall himself, had his work published in the Royal Society journal Proceedings B. this week. Stulp worked together with Felix Tropf of the RUG, Louise Barrett of the University of Lethbridge in Canada, and LifeLines, a Groningen-based biobank and platform for studying healthy ageing and disease development, among others. Stulp’s supervisor at the time, Melinda Mills, provided access to the LifeLines database.

One component of LifeLine’s work has been to compile information about men and women in the northern region of the Netherlands. Interestingly, in the north, the height difference is even more pronounced: Groningers are 1.5 centimetres taller on average than people from other parts of the Netherlands, Stulp says.