According to United States government data, the average height for U.S. adult males is 1.77 metres (5 feet 9.9 inches), with the average female measuring 1.63 metres (5 feet 4.3 inches). The average height of humans varies greatly across the world and depends on a number of factors including genetics and nutrition. It is difficult to come up with an exact worldwide average height because of variability in data collection between nations. Average human height has also fluctuated significantly throughout history.
Geographical and ethnic differences
Height averages vary significantly from nation to nation and within large nations as well. Human height is dependent on both nature and nurture. Both hereditary genetic factors and environmental factors like diet, exercise and living conditions determine the height of an individual. Areas that experience severe malnutrition, war, and natural disasters typically have lower average heights than places with healthier populations. There are also significant differences between the average heights of people of different ethnicities. For example, Asian people are typically shorter than people of Anglo-Saxon decent. According to a 2007 study by fitting company Alvanon, the average male in China was about 2.5 cm (one inch) shorter than the average American male.
Men and women
Within a given population, men are always taller than women on average. Women do typically reach their full adult height at a younger age, but men generally surpass them by their early 20s. The difference in height is attributed to sex chromosomal differences in males (XY) and females (XX). Although women of one ethnicity may be taller than the men of another ethnicity, the average difference between males and females within an ethnic population is usually consistent.
Human height throughout history
Average height has oscillated throughout human history. The average height of a large population at a given moment in history often says a lot about the living conditions at that time. An Ohio State University study determined that European men during the 17th century averaged 1.65 metres (5 feet 5 inches) tall, whereas today they are a few inches taller. He attributes this to the abnormally cold weather and widespread political crisis in Europe during that century. The study also found that the Cheyenne people of North America were some of the tallest human beings ever to inhabit earth. He attributes this to the high protein, buffalo based diet of the Cheyenne.
Height abnormalities such as dwarfism and gigantism are extremely rare and do not generally affect height averages across a given population. At 2.46 metres (8 feet 11.1 inches) tall, Illinois native Robert Pershing Wadlow was the tallest man ever measured. Madge Bester of South Africa is the shortest living female at just 0.66 metres (26 inches).
Future of human height
Currently, the Dutch are on average the tallest people on Earth, with average male heights at roughly 1.82 metres (6 feet). Height historian John Kolmos predicts that this trend will continue until the Dutch level off at the ideal human height of about 1.87 metres (6 feet 2 inches) for men and 1.72 metres (5 feet 8 inches) for women. Scientists and historians such as Kolmos and Steckel continue to look to the past for answers about the future of human height and what it can tell us about the human body and its potential.