America is a nation of fat-heads. But hey, don't shoot the messenger; we're just passing on the news from a recent study, which suggests that the heads of white Americans are growing in volume, year-on-year.
The research, carried out by forensic anthropologists at the University of Tennessee, Knoxville, examined 1,500 skulls dating back as far as the mid-1800s. Over time, it seems, the heads of white Americans have become larger in volume — but oddly, that's because they've been getting much taller, as they've also grown narrower over the period.
In total, the skull of the average male human has grown by 200 cubic centimeters. If you're struggling to picture that, it's about the same volume as that occupied by a tennis ball. Women aren't far behind, either, with their skulls by grown by 180 cubic centimeters. The findings were reported at the annual meeting of the American Association of Physical Anthropologists.
So, ummm, why is it happening? Actually, nobody is really sure. Richard Jantz, one of the researchers, explains that "the varieties of changes that have swept American life make determining an exact cause an endlessly complicated proposition."
However, there are some obvious possible explanations. First is the breakdown of former ethnic barriers to marriage, which means that distinctive skull shapes of different races have become more dilute throughout society. Second is the dramatic change in nutrition over the last 200 years, which accounts for the general upward trend in human size around the world. Combined, they could easily have led to the fat heads Americans now sport. [Science Guru]
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