I guess this is big brain week.
The latest episode of the Brain Science Podcast has an interview with Gary Lynch discussing his book Big Brain: The Origins and Future of Human Intelligence.
A very accessible discussion of, among other things, how the human brain evolved to be so big. His position is that there was no natural selection pressure in favor of greater intelligence (even today, many, many people do just fine with very limited intelligence. Just look at Sarah Palin!).
Rather, when our distant ancestors became bipedal, the size of the birth canal increased, and this led to larger-brained babies.
Intelligence was just an accidental side effect.
