A study about height of Americans versus citizens of others countries found that Americans now rank 37th in the world in terms of height. One hundred years ago, Americans were the 3rd tallest. Using data from epidemiological studies and population health surveys, they looked at height for 18.6 million adults born between 1896 and 1996:
Height is one of the most heritable human traits, but the researchers say environment also plays a role. “Genetics doesn't change so quickly, so if you see a change over 100 years, it has to be environmental,” says the new study’s co-lead author, Mariachiara Di Cesare, now at Middlesex University London. A major influence on height, especially early in life, is nutrition. Another is childhood infections, so clean water and health care are also important.Essentially, these findings are a sign - according to the authors - that conditions are improving in many countries, which explains the increase in height:
The authors assert that the study shows the potential of using height as an indicator of human development. It is easily measured and provides a link between early-life experiences, health, longevity, education and earnings.The other is this picture, which I present without comment:
And in response to the claims Trump has made with regard to hand size and other potentially related measurements, I give you this Snopes link.