Posted on June 6, 2012

White Americans’ Heads Are Getting Bigger — Literally, Study Shows

Meghan Holohan, MSNBC, June 4, 2012

If someone complains that a person has a big head, it’s normally considered a dig at the enormity of that person’s ego. But when it comes to white Americans, being labeled as big-headed shouldn’t be considered a criticism as much as an apt description: Over the past 150 years, the size of white Americans’ craniums have actually increased in size.

Researchers at the University of Tennessee’s Forensic Anthropology Center (what Mary Roach calls “the body farm” in her book “Stiff”) routinely examine skulls to try to determine sex and race of the craniums so if police officers discover just a skull, there are guidelines for gleaning info about it. The database of skulls and bodies has steadily increased to include people who were born and died in the 20th century, whereas prior the skulls were from people born in the 19th century.

As researchers Lee Jantz, coordinator of Forensic Anthropology Center, Richard Jantz, professor emeritus, and Joanne Devlin, adjunct assistant professor, catalogued 1,500 noggins they observed that white people who were born in the 20th century had bigger heads.

They looked at white skulls because they wanted to have a large sample and they don’t have as many black and Hispanic skulls. {snip}

The height of white male skulls has increased by eight millimeters and the overall skull has grown by 200 cubic centimeters. For women, cranium height increased by seven millimeters and overall by 180 cubic centimeters.

“The basic thing that we observed over the course of looking at crania that belong to people born from 1820s to 1980s, is that the cranium has gotten higher and narrower,” says Richard Jantz, who is married to Lee.

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Bigger heads typically mean bigger brains, and while Richard Jantz and his colleagues did not look at brain size, he suspects brain size also increased. There are several theories why brains might be brawnier.

Over the past 100 years, life in America changed dramatically. People no longer toil in the fields, and they don’t struggle to consume enough calories. We have too much food and not enough physical activity. This means our bodies don’t have to divide fewer calories between the body and the brain, so enough energy can go to the brain, allowing it to balloon. Improved medicine also contributes to larger heads — in the past babies with bulbous heads could not escape the birth canal and many died. With the increase of C-sections, more and more of these big-headed babes make it into the world.

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Jantz also notes that Americans mature faster now than they did in earlier centuries. In the 19th century, on average, girls reached menarche at 16 or 17, whereas modern girls reach it by 12 or 13, indicating that humans are growing more rapidly.

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