My guess is that it has to do with language. More specifically, it helps higher pitched sounds to resonate louder and more distinctively from other sounds. Plus some sexual selection.
When these thing pop up for some reason my default is assume sexual selection. Chins? sexual selection. Breasts, sexual selection. A sense of humor? Believe it or not sexual selection.
My guess is that it has to do with language. More specifically, it helps higher pitched sounds to resonate louder and more distinctively from other sounds. Plus some sexual selection.
When these thing pop up for some reason my default is assume sexual selection. Chins? sexual selection. Breasts, sexual selection. A sense of humor? Believe it or not sexual selection.
Pretty much, but what is being selected for is also interesting. Perhaps it isn’t the chin itself, but the resonance and its effect on our voices.
It’s just my guess, mind you.