american skull

American skulls have significantly gotten larger in the past seven generations, and still growing

american skullA new study from anthropologists at University of Tennessee analyzed the skulls of caucasian American men and women from between the mid-1800s to the mid-1900s. Their findings showed that the average American’s skull today is larger and narrower than it used to be seven generations ago.

In total, over 1,500 skulls have been analyzed, and though humans are taller, in general, than they used to be, say a hundred or two hundred years ago, the growth in skull size is disproportional to the rest of the body, suggesting other factors are at work.

“The varieties of changes that have swept American life make determining an exact cause an endlessly complicated proposition,” says Lee Jantz, coordinator of UT’s Forensic Anthropology Center (FAC).

“It likely results from modified growth patterns because of better nutrition, lower infant and maternal mortality, less physical work, and a breakdown of former ethnic barriers to marriage. Which of these is paramount we do not know.”

The researchers found that the average height from the base to the top of the skull in men has increased by eight millimeters, or about a third of an inch, resulting in an increase in skull volume of around 200 cubic centimeters ~ just about that of a tennis ball. In women, the corresponding increases are seven millimeters and 180 cubic centimeters.

Are American brains getting bigger too? Well, for one brain size had been found to be correlated with skull size in previous studies, but this has not been proven yet, given the short supply of 1800s brains, probably…

Is the increase in skull size part of a larger pattern of the human body growing in general? Like I said earlier, humans have grown taller than they used to. Body height has increased by 5.6 percent and femur length by two percent, the UT study shows, while skull height  has increased 6.8 percent since the late 1800s. Also the study found that Americans are maturing faster than before. A separation in the bone structure of the skull called the spheno-occipital synchondrosis, which in the past was thought to fuse at about age twenty, is now fusing much earlier – 14 for girls and 16 for boys.

One possible reason is America’s obesity epidemic.

“This might affect skull shape by changing the hormonal environment, which in turn could affect timing of growth and maturation,” says professor emeritus  Richard Jantz.

“We know it has an effect on the long bones by increasing muscle attachment areas, increasing arthritis at certain joints, especially the knee, and increasing the weight-bearing capacity.”

Previous studies have also revealed an increase in skull size among European populations, however not this significant. The team of researchers presented their findings at the American Association of Physical Anthropologists meeting in April.


6 thoughts on “American skulls have significantly gotten larger in the past seven generations, and still growing

  1. Keith Cole

    Food has become more readily available. Industry and farming are more productive. No Wal-Marts in the 1800s

  2. Pigtails

    mmmm I dunno. The study looked at skulls up to the mid 1900’s. So the looked at skulls up to 1950 presumably. We didn’t have an obesity epidemic until the 80’s when high fructose corn syrup made sugary foods ultra cheap.

  3. Taylor

    Maybe instead of the skull they should look at the brain. It may be possible that an increased growth rate of the brain caused our bodies to grow bigger skulls. Education in and of itself could have a great deal to do with the increased size of the brain as well. education has changed tremendously. human children learn a huge amount in a small amount of time. Starting, typically, from age five they then learn constantly til about the age 18-24, this does not include the extra learning needed for higher degrees. these years are also a human child’s main growing years, it is quite possible that over time our hormones and evolution have decided to not only increase the standard features of humans but as well as add more to what makes us the dominant species.

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