Science

A SHORT HISTORY OF HEIGHT

Canadians are now taller than Americans, who have suddenly plateaued—but all tre towering Dutch. So what's their secret?

CHRISTOPHER WATT April 4 2005
Science

A SHORT HISTORY OF HEIGHT

Canadians are now taller than Americans, who have suddenly plateaued—but all tre towering Dutch. So what's their secret?

CHRISTOPHER WATT April 4 2005

A SHORT HISTORY OF HEIGHT

Science

Canadians are now taller than Americans, who have suddenly plateaued —but all tre towering Dutch. So what's their secret?

CHRISTOPHER WATT

RICHARD STECKEL HAS A REALITY CHECK for parents who see their teenagers sprouting skyward before their very eyes. It’s really happening. Young Canadians today enjoy such stunning nutritional advantage over their predecessors that it is now possible for most to reach their full genetic potential, their optimum height. But what baffles experts like Steckel is that America’s young adults, who share much the same diet, have suddenly plateaued. And while Canadians continue to inch upward, overtaking our richer neighbours, both

countries lag behing the now towering Dutch. What is behind such differences? Junk food diets pushing more people outward than upward? Social disparities? Height, it seems, is about more than what’s in our genes.

An economic historian at Ohio State University, Steckel has spent years scouring the boneyards and archives of the western hemisphere searching for clues about the height and health of past populations. He has shown, for example, that in the early 1800s the Cheyenne of the U.S. Plains were among the tallest people in the world, taller on average than Americans and Europeans. At an average of five foot ten for men, the Cheyenne were also taller than their native neighbours to the north, the Assiniboine of Manitoba. Similar genes and cultures. But, Steckel notes, the Cheyenne enjoyed milder winters, enabling them to hunt the highprotein buffalo more easily year round.

Equally intriguing are Steckel’s conclusions about height across the millennia. Northern Europeans in the 11th century were substantially taller—almost three inches taller on average—than their descendants on the eve of the industrial revolution around 1750. That might seem bizarre to anyone accustomed to thinking about human height as something that has increased steadily with the so-called march of civilization. But height varies with how healthy and how well off a given society is as a whole, says John Komlos, a prominent height historian at the University of Munich. “We’ve yet to recognize,” says Komlos, “how sensitive the human body is to socio-economic and environmental circumstances.”

In the late 1700s, for example, Americanborn colonialists made good use of their

sparsely populated, protein-rich environment to become taller than their European contemporaries: average height was five foot eight for American men, judging from military and prison records. That was nearly two inches taller than the average British soldier. Just decades later, however, a strange stunting started to occur that researchers don’t fully understand. American incomes rose from the early to mid-1800s, but that didn’t equate to better living conditions. As Americans became richer—as a group anyway—they also shrank.

By the early 1900s, Americans were again among the world’s tallest people. But now measurers are starting to detect another mysterious levelling off. At an average of five foot ten, American-born men from the 1970s are not much taller than their greatgrandfathers. So much for the modern diet.

Canada, however, is still shooting upward. At just over five foot eleven, the average Canadian-born male from the 1970s stands nearly an inch taller than his American counterpart. And while it’s nice to be taller than our well-fed neighbours, we still trail the Netherlands, whose citizens are now considered the tallest in the world. Starting in the 1840s, the Dutch began growing from generation to generation, to the point where just over six feet is average for men in their 20s and 30s.

For women the gap is even greater. At an average of five foot eight, Dutch women stand nearly four inches taller than their American-born counterparts. America might possess the mightiest economy and a supersized larder, but it has become clear such wealth doesn’t necessarily translate into healthier or taller populations. In the space

of about 140 years, the average Americans have gone from being three inches taller than the Dutch to three inches shorter.

According to Steckel, it’s the relative equality within Dutch and other European

THE BIG gainers

are nations with health coverage, protein-rich diets and relatively low income inequality

societies that are helping them grow. “If you take a dollar from the richest and give it to the poor,” Steckel says, “heights will increase.” Nations with universal health coverage, protein-rich diets and relatively low income inequality—like the Netherlands and Canada—continue to get taller. That may not have always been the case. University of Guelph economist Kris Inwood believes Canadians went through the same pattern as Americans in the 19th century, getting shorter as incomes rose. But Canada began to reverse the so-called urban penalty around 1910. As big cities were

cleaned up and milk programs took root in schools, Canadians grew.

That urban penalty made for some noticeable regional differences in the 1800s. “Ontario was taller than the Maritimes, and both were taller than Quebec,” says Inwood. “Quebec wasn’t the poorest, but it had the most inequality.” It also had some of the oldest—and dirtiest—cities in Canada. According to Peter Ward at the University of British Columbia, Montreal in the 19th century was “one of the

unhealthiest cities in the western world.”

A low point in human stature, notes Komlos, was during a very cold period in the 17th century. It was also a century of political crisis, marked by the Thirty Years War between Catholics and Protestants, which ravaged much of Western Europe. “I think a lot of that political upheaval had to do with the bad climate,” speculates Komlos. “It meant agricultural productivity was down, and it was more difficult for people to feed themselves.” Frenchmen, for example, averaged five foot three during that period, while women were about three inches shorter. When that data is compared with Steckel’s findings from late-Medieval Europe, a remarkable trend emerges. Komlos’s growthstunted French were much shorter than Europeans who lived before the so-called little ice age of the 17th century and before cities—efficient incubators of disease—began to appear. Northern Europeans, in fact, shrank from a peak average height of just over five foot eight in the 11th century to five foot five and change in the 17th. It took generations before they would grow again.

One intriguing new finding is that the elites of Europe, Asia and Africa now actually all stand about the same height, roughly five foot ten to six foot, according to Steckel. What’s different are the paths through history those groups took to achieve that stature. And what the experts don’t know, of course, is how tall humans can or should be.

Economists have long speculated on the benefits that can go to tall people. Some studies have suggested business executives of around six foot three or four earn more than their shorter peers. But the very tall have their problems too. While the relatively tall live longer, studies show that the positive relationship between height and life expectancy changes for the worse among men taller than six foot two, who face an increased risk of heart disease. Longevitywise, tall is good. Too tall is not.

Komlos believes the Dutch will remain the world’s tallest people for some time yet, eventually achieving what might be seen as ideal heights—averages of six foot two for men and five foot eight for women—for what he calls the optimum “biological standard of living.” Meanwhile, combing through army records and burial sites, social explorers like Steckel are looking ever backward, trying to piece together a complete picture of human height, in all its ups and downs. f!fl