Great book by a human evolutionary biologist which helps me understand why humans are the way we are: non-rational but still able to cooperate in large groups. I’d liken it to Sapiens in its attempts but the material is more advanced and it is better cited. Before reading, I didn’t know much about cultural evolution and culture-gene coevolution. After the author’s claims and presentation of evidence I am more convinced that (1) these exist and (2) they contribute drastically to our behaviors and structures today (as well as in the past.) Cooperation is a part of it, but there is so much more! Ie: How do we seem so intelligent when we are irrational, what are mechanisms for establishing cooperation, and what does (did) this mean for our species? In sum: social norm formation, random tool invention/improvement, and language development all culturally developed/evolved in small groups of humans (and pre-humans) and self-amplified through various mechanisms (genetic and non-genetic.) How children absorb rules and norms was particularly eye opening to me. The subject is obviously not one where you can perfectly apply the scientific method but I think he does a magnificent job with his studies and presentation. Admittedly though, I am not smart/knowledgeable enough (or haven't been exposed to the appropriate amount of cultural learning) to know if items have been cherry picked or excluded to fit his thesis. The end (why terrestrial apes vs other animals) is certainly more speculative but gives science many frontiers to take a look at.

As an added bonus, there may be insights into human happiness in this book by analyzing social norms/rituals/behaviors and their relation to human cultural evolution.