Joseph Henrich, The Secret of Our Success: How Culture Is Driving Human Evolution, Domesticating Our Species, and Making Us Smarter (2016)

An amazing book, certainly a leading candidate for my book of the year. I had read and greatly admired Henrich's more recent book, The WEIRDEST People in the World (2020). I knew that Henrich was a student (by now, clearly the leading student) of Robert Boyd and Peter Richerson, who since the 1980s have pioneered work on gene-culture coevolution. I haven't read Boyd and Richerson's works (for example, Culture and the Evolutionary Process [1985] or Not By Genes Alone [2005]) in quite a few years, so I can't say precisely how Henrich builds on, and perhaps modifies, their approach. Henrich makes a persuasive case that cultural evolution - learning ideas, techniques, facts and values from others - has become the dominant force shaping human genetic evolution over roughly the last two million years. Just to give one among Henrich's innumerable fascinating examples, one of early humans' early advantages was that we became excellent pursuit hunters. Even though we weren't faster or stronger than most animals, we became able to track animal spoor and, over hours, run our prey into exhaustion. In order to become excellent long-distance runners, our legs had to become longer and we had to develop the ability to sweat over much of our bodies. However, certain skills and technologies were also required, such as the ability to follow the tracks of particular individual animals, and the ability to carry water with us or extract it from the ground. These skills and technologies, Henrich shows, could never have been developed by individuals or even by groups - they had to evolve culturally, over generations. A key concept for Henrich is cumulative cultural evolution - culture (technologies, say) build on previous culture. Henrich has command of a wide range of literatures, showing how multiple streams of evidence support his case. As I said, I can't say exactly how his argument compares to Boyd and Richerson's, but I think he puts cultural evolution even more in the driver's seat than they did. As he says, he's proposing a new science of "a new kind of animal," one that draws on a collective brain to solve problems. Citing John Maynard Smith and Eors Szathmary's work on major transitions in evolution, Henrich suggests humans now find themselves in just such a transition to super-organisms. On a smaller scale, I learned fascinating things about "faith," i.e. trust in cultural processes that are smarter than any individual's intelligence; humans' two systems of status hierarchy - the dominance hierarchy we've inherited from our great ape forebears, and a newer prestige hierarchy; how our perception of "races" (sometimes mistakenly) draws on our "ethnic" psychology, which uses cues such as dialect and clothing to determine if somebody likely shares our norms; the close ties between tool making and language; etc. This short, and hastily written, comment doesn't do justice to this landmark book.