New Study Explains Why Humans Have Chins

posted: 04/14/15
by: Discovery.com Staff
Human skull, side view, studio shot
Siri Stafford/Thinkstock

A new study from the University of Iowa repudiates the long-held belief that humans developed chins as an evolutionary adaptation to aid in chewing.

Instead, researchers attribute the chin's emergence to changes in hormone levels caused by social domestication. As humans began to cooperate and develop social relationships, they engaged in fewer physical confrontations for territory and property. Thus, testosterone levels in humans dropped and the shape of the the human skull was altered accordingly.

"What we're arguing is that modern humans had an advantage at some point to have a well-connected social network, they can exchange information, and mates, more readily, there's innovation," noted Robert Franciscus, study lead author. "For that to happen, males have to tolerate each other. There had to be more curiosity and inquisitiveness than aggression, and the evidence of that lies in facial architecture."

Click here for more information from the University of Iowa

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