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.
The average American man is only five feet nine and a half—less than an inch taller than the average soldier during the Revolutionary War.  Women, meanwhile, seem to be getting smaller. (...)

Compared with people in thirty-six other industrialized countries, it showed, Americans rank twenty-eighth in average longevity—just above the Irish and the Cypriots (the Japanese top the rankings). “Ask yourself this,” Komlos said, peering at me above his reading glasses.
“What is the difference between Western Europe and the U.S. that would work in this direction? It’s not income, since Americans, at least on paper, have been wealthier for more than a century. So what is it?” The obvious answer would seem to be immigration. The more Mexicans and Chinese there are in the United States, the shorter the American population becomes. But the height statistics that Komlos cites include only native-born Americans who speak English at home, and he is careful to screen out people of Asian and Hispanic descent.
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. (...)

Tall men, a series of studies has shown, benefit from a significant bias. They get married sooner, get promoted quicker, and earn higher wages. According to one recent study, the average six-foot worker earns a hundred and sixty-six thousand dollars more, over a thirty-year period, than his five-foot-five-inch counterpart—about eight hundred dollars more per inch per year. Short men are unlucky in politics (only five of forty-three Presidents have been shorter than average) and unluckier in love.