Navigation Links
University of Tennessee anthropologists find American heads are getting larger

White Americans' heads are getting bigger. That's according to research by forensic anthropologists at the University of Tennessee, Knoxville.

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 U.S. skulls have become larger, taller and narrower as seen from the front and faces have become significantly narrower and higher.

The researchers cannot pinpoint a reason as to why American head shapes are changing and whether it is primarily due to evolution or lifestyle changes.

"The varieties of changes that have swept American life make determining an exact cause an endlessly complicated proposition," said Lee Jantz. "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 (0.3 inches). The skull size has grown by 200 cubic centimeters, a space equivalent to a tennis ball. In women, the corresponding increases are seven millimeters and 180 cubic centimeters.

Skull height has increased 6.8 percent since the late 1800s, while body height has increased 5.6 percent and femur length has only increased about 2 percent. Also, skull-height has continued to change whereas the overall heightening has recently slowed or stopped.

The scientists also noted changes that illustrate our population is maturing sooner. This is reflected in the earlier closing of 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. Richard Jantz and Natalie Shirley, an adjunct assistant professor in the FAC, have found the bone is fusing much earlier 14 for girls and 16 for boys.

America's obesity epidemic is the latest development that could affect skeletal shape but its precise effects are unclear.

"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 research only assessed Americans of European ancestry because they provided the largest sample sizes to work with. Richard Jantz said changes in skeletal structure are taking place in many parts of the world, but tend to be less studied. He said research has uncovered shifts in skull shape in Europe though it is not as dramatic as seen in the U.S.

The findings were presented on April 14 in Portland, Ore. at the annual meeting of the American Association of Physical Anthropologists.


Contact: Whitney Heins
University of Tennessee at Knoxville

Related biology news :

1. Rice University establishes National Corrosion Center
2. Case Western Reserve University researchers track Chernobyl fallout
3. Case Western Reserve University project ties soil conservation and river management together
4. Brown University and Women & Infants Hospital expand national childrens study to Bristol County
5. NIH selects Case Western Reserve University to participate in National Childrens Study
6. US Senate confirms Clemson University engineering Dean Esin Gulari to National Science Board
7. University professor stresses links between US Navy sonar and whale strandings
8. Scent on demand: Hebrew University scientists enhance the scent of flowers
9. University success at national engineering awards
10. University of Leicester professor adds new perspective to rainforest debate
11. Providing toilets, safe water is top route to reducing world poverty: UN University
Post Your Comments:
(Date:9/28/2015)... , Sept. 28, 2015 ... today that its expedited traveler service is ... platform transforms travel, bringing a frictionless experience, ... members. "CLEAR offers our travelers ... customer service," said Jim Smith , ...
(Date:9/28/2015)... 2015 The global image ... 12.03 billion by 2020, growing at a CAGR of ... Backside Illumination (BSI) technique to improve picture quality are ...      (Logo: , The ... reduce loss and, thus, reduce the noise interference and ...
(Date:9/28/2015)... Calif. , Sept. 28, 2015 Synaptics ... human interface solutions, today announced that Lenovo has selected ... fingerprint sensor, FS4202, for its latest smartphone, the Vibe ... password-free access to unlock the device and provide swift ... The feature-rich Natural ID FS4202 sensor solution ...
Breaking Biology News(10 mins):
(Date:10/12/2015)... , Oct. 12, 2015  Patara Pharma, ... allergic and inflammatory diseases and conditions, today announced ... preferred stock financing. Concurrent with the close of ... into a Loan and Security Agreement with Silicon ... to $7 million. Patara will use the funds ...
(Date:10/12/2015)... offers user-friendly, ... online experience --> ... for enriched online experience --> ... to print version for enriched online experience ... and medical information products and services, announced today that ...
(Date:10/12/2015)... ... October 12, 2015 , ... Dr. ... Srinivasan, has joined the firm as a Premier Expert consultant. NDA Partners ... to bring extraordinary value to the company's clients. Premier Experts collaborate to ...
(Date:10/12/2015)... ... October 12, 2015 , ... LifeTrak , a ... of LifeTrak Zoom, the world’s first amphibious fitness tracker that seeks to meet the ... technology and accurate heart rate monitoring both in water and on land, ...
Breaking Biology Technology: