Q: Are humans getting taller, on average, over time?

A: Yes, says John Hawks, who studies genetics and human evolution in the UW- Madison department of anthropology.

"We have definitely gotten taller over the last 200 or 300 years," he said.

George Washington was an inch or two above 6 feet tall, and "people said he was the tallest person they ever saw; he was really imposing in size."

One cause of the increase is the decline in childhood diseases like scarlet fever, rheumatic fever and diphtheria, which were largely eliminated by vaccines and antibiotics. If these infections did not kill, they often stunted the growth of infants and children, sometimes with lifelong damage, Hawks said.

Better nutrition is the other explanation for the increase. Even if a few people ate well a few centuries ago, "many were lacking certain vitamins, and a larger percentage had trouble getting foods that maximize growth," Hawks said.

The benefits of good nutrition are cumulative, Hawks adds, because larger mothers tend to have larger babies.

- Produced in cooperation with University Communications

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