Don’t let it go to your head, but researchers at the University of Tennessee, Knoxville say Caucasian Americans’ heads are getting bigger.
Lee Jantz, coordinator of UT’s Forensic Anthropology Center (FAC); Richard Jantz, professor emeritus and former director of the FAC; and Joanne Devlin, adjunct assistant professor, examined 1,500 skulls dating back to the mid-1800s through the mid-1980s. They noticed US skulls have become larger, taller, and narrower as seen from the front and faces have become significantly narrower and higher.
The research team wasn’t able to determine why our head shapes are changing.
“The varieties of changes that have swept American life make determining an exact cause an endlessly complicated proposition,” Lee Jantz said in a university news release. “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 study found that the average height for a man’s skull has increased by 8 millimeters (0.3 inches) and the average size has expanded by 200 cubic centimeters – a space equivalent to the size of a tennis ball. Women’s skulls saw slightly smaller levels of growth and expansion (7 millimeters and 180 cubic centimeters).
It also appears our heads are growing at a faster rate than other parts of our bodies. Average skull height is up 6.8% since the 1800s while average body height has increased by just 5.6% and femur (thigh bone) length has grown by 2%.
Researchers say America’s obesity epidemic could have an impact on our skeletal structures moving forward.
“This might affect skull shape by changing the hormonal environment, which in turn could affect timing of growth and maturation,” said 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.”
The team also found Americans’ heads have experienced more dramatic growth than our European counterparts.