“If you’re looking across all of the hominids, which is the family tree after the split with chimpanzees, there [are] not really that many traits that we can point to that we can say are exclusively human,” Duke University’s James Pampush tells Robert Siegel for NPR. “[T]hose animals all walked on two legs. The one thing that really sticks out is the chin.”
One of the most popular ideas is that our ancestors evolved chins to strengthen our lower jaws to withstand the stresses of chewing. But according to Pampush, the chin is in the wrong place to reinforce the jaw. As for helping us speak, he doubts that the tongue generates enough force to make this necessary. A third idea is that the chin could help people choose mates, but sexually selective features like this typically only develop in one gender, Pampush tells Siegel.
The spandrel hypothesis is as good a theory as any, but it too has its problems. It’s hard to find evidence to test if something is an evolutionary byproduct, especially if it doesn’t serve an obvious function. But if researchers one day do manage to figure out where the chin came from, it could put together another piece of the puzzle of what makes us different from our primate and Neanderthal cousins, Yong writes.
The dismissal of a sexually selected trait just because it usually is far more pronounced in one sex than the other seems extemely premature to me.
I would argue chins are actually already quite different between the sexes - to the point where people will have surgery to change their appearance if their chin doesn’t conform to societal ideals.
Sexually selected trait seems like an avenue of research that shouldn’t be so easily dismissed.
hard to find evidince
This is, like, an undergrad project.
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work with the depressed grad student who is good at stats to determine the parameters of your experiment at the outset and calculate the number of subjects and stimuli for statistical power; pay in marking or research help.
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get an appropriate number of headshots from undergrad males for stimuli, give them intro psyc course credit for participating.
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work with mid-degree graphic design students to give all headshots 3 levels of chins (low, normal, emphasized), ensuring none are comical; the the psyc grad student signs off on the work as portfolio credit
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have an appropriate number of undergrad cis-het women subjects rate a your lineup for attractiveness; intro psyc course credit for participation
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analyze the results to see if low chin is selected less than normal or emphasized.
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submit your research paper and results; get your 4th year class capstone. Grad student takes your work and adds it to their dissertation, you get a footnote.
I’m sure this has been done…
