A study found men are significantly taller than they were in the good old 1800s.

The average male height increased 11 centimeters (around four inches) between the mid nineteenth century and the 1980s, an Oxford University press release reported.

"Increases in human stature are a key indicator of improvements in the average health of populations. 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," Timothy J. Hatton, Professor of Economics at the University of Essex, said.

The researchers analyzed datasets of the average male height at 21. Only men were included in the study because historical records of female height are limited, most of the information on male height was taken from military data. The team looked at men from 15 different countries and from various generations.

In Spain the average height went up 12 centimeters between the 1870s and 1970s. in Sweden, men grew 10 centimeters, Reuters reported.

In the 1870s infant mortality rates were at 178 per thousand. The rate plummeted to only 41 in every thousand by the 1950s, and then dropped to 14 in the late 1970s, according to the press release.

There was a "distinct quickening" in the increase of average male height in the period spanning the two world wars. This finding is unusual because it comes before modern medicine breakthroughs that would have helped increase height. During this era there was a distinct decline infertility, which may have led to the steep increase.  Smaller family size has been linked with increased height in previous studies.

Other factors that can lead to taller humans include: higher income, sanitary living conditions,  better health and nutrition education, and better social service and health care systems.