According to a new paper published online in the journal Oxford Economic Papers, the average height of European males increased by an astounding 11 cm from the mid-nineteenth century until 1980. Despite different expectations, the study also revealed that the average height accelerated between the two World Wars and the Great Depression.

Timothy J. Hatton, Professor of Economics at the University of Essex and the Research School of Economics at Australian National University in Canberra, analyzed new data for the average height of adult males around the age of 21 from the 1870s to 1980 in 15 different European countries. The data was collected from several different sources. For recent decades height by age data was taken from cross sectional  surveys. Data for earlier years was based on records from military conscripts and recruits. The data was for men only since historical evidence for women is limited.

“Increases in human stature are a key indicator of improvements in the average health of populations,” Hatton said. “The evidence suggests that the improving disease environment, as reflected in the fall in infant mortality, is the single most important factor driving the increase in height. The link between infant mortality and height has already been demonstrated by a number of studies.”

Infant mortality rates fell from an average of 178 per thousand in 1871-5 to 120 per thousand in 1911-15. They then fell even further to 41 per thousand in 1951-5 and 14 per thousand in 1976-80.

In northern and middle European countries such as Britain and Ireland, as well as Scandinavian countries such as Netherlands, Austria, Belgium and Germany there was a distinct increase in height advancement during the time of the two World Wars and the Great Depression. This is surprising due to the fact that the period largely predates the widely implemented major breakthroughs in modern medicine and national health services.

One possible reason for the rapid increase, in addition to the decline in infant morality, is that a strong downward trend in fertility occurred during this time. Smaller family sizes have already been linked to increases in height.

Other factors for the height increase could be an increase in per capita income, more sanitary living conditions, better education, better health and nutrition for all family members and better social services and health systems being available.

Genes might commonly be seen as the main determinant of height, but even though they explain the differences between individuals, they do not explain the trend seen here, Hatton noted.

“People are surviving in the 20th Century who would not have survived in the 19th,” Hatton said.