"Like many biases, this one has a certain basis in fact. Over the past thirty years, a new breed of “anthropometric historians” has tracked how populations around the world have changed in stature. Height, they’ve concluded, is a kind of biological shorthand: a composite code for all the factors that make up a society’s well-being. Height variations within a population are largely genetic, but height variations between populations are mostly environmental, anthropometric history suggests. If Joe is taller than Jack, it’s probably because his parents are taller. But if the average Norwegian is taller than the average Nigerian it’s because Norwegians live healthier lives. That’s why the United Nations now uses height to monitor nutrition in developing countries. In our height lies the tale of our birth and upbringing, of our social class, daily diet, and health-care coverage. In our height lies our history."
'The immediate point was clear: America was a good place to live in the eighteenth century. Game was abundant, land free for the clearing, settlement sparse enough to prevent epidemics. On Komlos’s graph, even the runaway slaves are five feet eight, and white colonists are five feet nine—a full three inches taller than the average European of the time. “So this is the eighteenth century,” Komlos said, slapping the files. “This is not problematic. It shows that Americans are well nourished. Terrific.” He reached into a cardboard folder and pulled out another series of graphs. “What is problematic is what comes next.”'
'Then something strange happened. While heights in Europe continued to climb, Komlos said, “the U.S. just went flat.” In the First World War, the average American soldier was still two inches taller than the average German. But sometime around 1955 the situation began to reverse. The Germans and other Europeans went on to grow an extra two centimetres a decade, and some Asian populations several times more, yet Americans haven’t grown taller in fifty years. By now, even the Japanese—once the shortest industrialized people on earth—have nearly caught up with us, and Northern Europeans are three inches taller and rising.'
'Inequality may be at the root of America’s height problem, but it’s too soon to be certain. If the poor are pulling all of us down with them, some economists say, why didn’t Americans shoot up after the war on poverty, in the nineteen-sixties? Komlos isn’t sure. But recently he has scoured his data for people who’ve bucked the national trend. He has subdivided the country’s heights by race, sex, income, and education. He has looked at whites alone, at blacks alone, at people with advanced degrees and those in the highest income bracket. Somewhere in the United States, he thinks, there must be a group that’s both so privileged and so socially insulated that it’s growing taller. He has yet to find one.'