Isn't there some evolutionary pressure, and it could be that it applies to primates in general and not just humans, for big-headedness? Like if big-headedness didn't help, then you could imagine two populations, A and B, where A has big heads and B doesn't. B loses fewer mothers during childbirth. Those mothers can then give birth more times, making B grow faster than A, so after enough time, we're all medium-head B-people. But somehow we ended up with me not being able to hold my head up in baby pictures. What gives?
Isn't there some evolutionary pressure, and it could be that it applies to primates in general and not just humans, for big-headedness? Like if big-headedness didn't help, then you could imagine two populations, A and B, where A has big heads and B doesn't. B loses fewer mothers during childbirth. Those mothers can then give birth more times, making B grow faster than A, so after enough time, we're all medium-head B-people. But somehow we ended up with me not being able to hold my head up in baby pictures. What gives?
Brain size does matter, but we also massively increased its efficiency during evolution and developed social 'tools' to utilize it better.