I picked this up because someone in a forum thread I can’t relocate anymore called it “the book that ruined individual genius for me,” and, yeah. Same. Henrich’s whole case is that human brains aren’t actually all that special on their own, what’s special is the culture, the accumulated tricks passed down and slightly improved generation over generation, and any one of us dropped alone into a hostile environment would die embarrassingly fast without that inheritance. He opens with explorers who starved to death in landscapes indigenous people had lived in comfortably for centuries, not because the explorers were stupid, but because they were smart in the wrong, individual way, reasoning from scratch instead of copying what worked.

What I didn’t expect was how much of the book is about detox recipes. There’s a stretch on how certain communities figured out, over probably hundreds of years of trial and error, exactly how to process cassava so it wouldn’t slowly poison you, a multi-day soaking and fermenting and drying process that nobody could reverse-engineer from first principles in one lifetime, and yet it got followed faithfully as “tradition” long after anyone remembered why. That’s the thing that stuck with me, that a lot of what looks like arbitrary custom from the outside is actually compressed, hard-won information, and the people following it without understanding it are frequently making the smarter choice than the person trying to reason it out fresh.

Only real gripe is the back third repeats itself, the cumulative-culture drum gets beaten a few chapters past where I’d stopped needing convincing. But I read this one twice already, close enough together that I know it’s going to be a book I hand to people, the same way I hand people Rings of Saturn even though the two share basically nothing except how much they rearranged my head afterward.