By Philip Copitch, Ph.D.
Anthropologists regularly assert that larger skulls hold larger brains, and that larger brains tend to depict greater intelligence. So, when I read that forensic anthropologists at the University of Tennessee found that Americans of European descent have shown skull growth over the last one hundred years, I got curious.
It's True... heads are getting bigger!
Forensic anthropologists at the University of Tennessee looked at 1,500 skulls from the 1800's to the mid 1980's. Because they needed a large sample size they only looked at skulls of Americans of European ancestry. The numbers are interesting. The researchers reported that skull size increased 6.8 percent, while body size increased 5.6 percent, and femur (thigh bone) length has increased almost 2 percent.
The forensic anthropologists made a point to say they didn't know for sure why the heads of Americans of European ancestry were growing so much. (You can fill in your own joke here: ______________) They did speculate that it was likely because of better nutrition, better health care, less physically demanding work, and/or intermarriage.
My thought on the subject...
...is that it is most likely better nutrition overall and, more specifically, better nutrition in the first five years of life. Other research has shown the importance of early childhood nutrition on overall adult body health and height.
Unfortunately, I don't think there is any evidence that our cranial size increase has lead to any societal increase in intelligence... but maybe I'm just being flippant.
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The findings were presented on April 14, 2012 in Portland, Oregon, at the annual meeting of the American Association of Physical Anthropologists, by Lee Jantz, coordinator of the University of Tennessee's Forensic Anthropology Center (FAC); Richard Jantz, professor emeritus and former director of the FAC; and Joanne Devlin, adjunct assistant professor.