Dutch men are tall, and Dutch women apparently like it that way. Scientists have found that natural selection—women choosing taller men to mate with—is a factor in the height of Dutch men, which has rocketed up by 20 cm (7.9 inches) over the past 200 years, while the heights of people in other similarly developed nations has—literally—only inched up.
In the mid 18th century, Dutch soldiers measured an average height of 165 cm (5 feet 4 inches). Back then, American soldiers “towered over” the Dutch by up to eight centimeters, according to research published today by the Royal Society in the UK.
But things have changed. Dutch men are now the tallest in the world, with an average man reaching 184 cm (6 feet). The Dutch are closely followed by Scandinavians, and are far taller than Americans, who have only grown by 6 cm (2.4 inches) over the same time period, to around 178 cm (5 feet 10 inches).
Heights have gradually increased in other developed countries too, but the upward trend elsewhere slowed or stopped much sooner than in the Netherlands, where it only began to slow recently (pdf).
The Dutch growth spurt has hitherto been attributed to environmental factors, including relative wealth and a rich diet. But the latest research, led by Gert Stulp of the London School of Hygiene and Tropical Medicine, put forth the hypothesis that natural selection had something to do with the change as well.
Stulp and his colleagues used a database of information from 168,000 Dutch people gathered between 1935 and 1967, and found that a preference for taller mates did indeed play a part. Taller than average men had more children overall, and more children that survived, while shorter men were less likely to reproduce.
Amongst women, it was those of average height who had more children overall, partly because they were more likely to have a partner than shorter or taller women. But when taller women were in a relationship, they were also found to have higher numbers of children overall.
Both taller women and taller men started families later, with taller men completing their education to a higher level before finding a partner and having children. Taller people have also been found in studies to earn more than their shorter counterparts.