|Neanderthal on the right, Human with a chin on the left...|
A recent BBC article explored this interesting topic, surveying the three main theories on why we have chins at all, pointing out that none of the theories is convincing, and therefore the mystery endures.
In this post I will propose what I believe is a novel theory on the subject.
Again, within all primates, chins evolved in only Anatomically Modern Humans. Researchers assume that the rise of chins should, therefore, be somehow connected to how we are different from all the rest.
I have previously asserted that the emergence of true human language was the catalyst that propelled Anatomically Modern Humans across the face of the planet.
I have also previously argued that true human language was initially originated by females of our species and only later was adopted by males.
And so, I propose that chins emerged alongside the development of true human language. As the first Anatomically Modern Humans arose in Africa, they were simultaneously experiencing language genesis.
The Chin as Counterbalance to the Nose
As a counterbalance to the nose, chins helped to focus attention onto the mouth. Humans with ever protruding chins were seen and listened to more than those without. They were, therefore, more successful within their communities. As a result, more and more prominent chins were selected by evolution.
Secondary evidence for my theory can be found in the fact that, after evolution had produced as large of chins as biology could feasibly muster, human societies then produced cultural measures to further focus attention onto the mouth.
In both Africa and North America, various cultures engaged in lip plating.
The women of the Ainu in Japan and Russia traditionally tattooed mustaches that drew attention to the area of their mouths.
The continued popularity of bright red lipstick (arguably to mimic the image of sexually aroused labia) is also certainly an example of a cultural highlight to the area of the mouth.
I offer this theory for consideration, knowing that none of the other theories as to why we have chins has managed to gain any traction. But I think my thesis is at least as compelling as the rest.