It might seem strange to some that there are scientists and historians whose primary focus is human height, but what might seem a rather banal subject at first is fascinating in the details.
For many anthropometric historians, the secrets of human history can be garnered from measuring bones or looking at records of the height of 17th century soldiers: in these small data points they can extrapolate everything from the health to the height to even the climate of people from centuries ago.
Yet the greatest mystery for anthropometric historians today is why some parts of the world of ‘growing’ while others are stagnant or even shrinking. ‘The American anomaly’ is the true puzzle: while Americans were once the tallest people on earth, their growth has stagnated in the past few decades. In the same century that the Dutch have grown 7 inches, American men have only grown half an inch and American women have actually shrunk by a third of an inch. So what is it about genetics and geography that causes people from different places to be of different heights?
The Science of Height: When we Grow, What We Wat and How We Live
Height is a combination of genetic and environmental factors, which over time compound to create different average heights in different societies. While you are likely to be tall if your parents are too, environmental factors can make a massive difference in little more than a generation. Humans have 3 distinct phases were growth can be altered: in infancy, in pre-pubescence and in the mid-teens. Any form of ill-health or malnutrition in these phases can adversely impact height, which is probably why North Koreans are now 3 inches shorter than South Koreans.
Because of this, societies that are richer and healthier are generally taller. This also helps to explain why we as humans have a psychological preference for taller partners and even taller leaders: taller people are more likely to be wealthy, healthy and better off by any number of factors. Yet if we accept the premise of riches equalling height as true, why are Americans (who have been the richest society on earth for several generations) just not growing?
The History of Height: Why Americans Were Once Giants on the Earth
Many presume that the correlation between height and wealth is linear, and that humans have been growing on average up until modern day. However this is not actually true: humans in antiquity were once as tall as they are now and actually have varied massively in height over the past few centuries. The ‘shortest’ people in known history on average was actually those of the 17th century, when it is thought that the ‘Little Ice Age’ created social conditions that successively shaved height off the previous generations.
It is here that America comes in to play as the anomaly of the study of height: while the rest of the world was getting shorter, Americans were on average the tallest people on earth. Aided by uncramped conditions, relative equality of nutrition and good health, Americans in the 18th century were at least 3 inches taller than their European counterparts. Even American slaves were taller than their African ancestors, taller than Europeans and equally as tall as American freemen. Yet in the mid-19th century, Americans simply stopped growing whilst simultaneously Europeans outgrew them by several inches.