For two centuries, the American man stood tall in the world. Literally. But today the average Dutch man is six foot one and the average American man is much shorter. Even as little as fifty years ago, American men were considerably taller than Dutch or other European men but since the mid 1950s the Northern Europeans have shot up while Americans have grown wider but not taller. No, it’s not a composition effect due to immigration. Native born, English-speaking American men are only five feet nine and a half and this has not changed much in more than a century. Why then the difference?
One possible clue is the enormous impact that nutrition can have on height. In Guatemala the native Mayan man averages only five foot two, so short compared to the Spanish-descended Ladinos that most people assumed the difference was genetic. But lo and behold when a million Guatemalans fled to the United States a natural experiment began – the children of the American Maya are four inches taller than the Guatemalan Maya of the same age and about as tall as the Ladinos. Good nutrition, especially in the growth years of infancy, 6-8 years and adolescence can increase height in remarkable fashion.
But if the problem is poor nutrition then surely the figures for the average American ought to be masking a growing drift in height between the well-fed rich and the poorly-fed poor? And yet that appears not to be the case. The mystery remains.