Bayesian Investor Blog

Book review: The Secret of Our Success: How Culture Is Driving Human Evolution, Domesticating Our Species, and Making Us Smarter, by Joseph Henrich.

This book provides a clear explanation of how an ability to learn cultural knowledge made humans evolve into something unique over the past few million years. It’s by far the best book I’ve read on human evolution.

Before reading this book, I thought human uniqueness depended on something somewhat arbitrary and mysterious which made sexual selection important for human evolution, and wondered whether human language abilities depended on some lucky mutation. Now I believe that the causes of human uniqueness were firmly in place 2-3 million years ago, and the remaining arbitrary events seem much farther back on the causal pathway (e.g. what was unique about apes? why did our ancestors descend from trees 4.4 million years ago? why did the climate become less stable 3 million years ago?)

Human language now seems like a natural byproduct of previous changes, and probably started sooner (and developed more gradually) than many researchers think.

I used to doubt that anyone could find good evidence of cultures that existed millions of years ago. But Henrich provides clear explanations of how features such as right-handedness and endurance running demonstrate important milestones in human abilities to generate culture.

Henrich’s most surprising claim is that there’s an important sense in which individual humans are no smarter than other apes. Our intellectual advantage over apes is mostly due to a somewhat special-purpose ability to combine our individual brains into a collective intelligence. His evidence on this point is weak, but it’s plausible enough to be interesting.

Henrich occasionally exaggerates a bit. The only place where that bothered me was where he claimed that heart attack patients who carefully adhered to taking placebos were half as likely to die as patients who failed to reliably take placebos. The author wants to believe that demonstrates the power of placebos. I say the patient failure to take placebos was just a symptom of an underlying health problem (dementia?).

I’m a bit surprised at how little Robin Hanson says about the Henrich’s main points. Henrich suggests that there’s cultural pressure to respect high-status people, for reasons that are somewhat at odds with Robin’s ally/coalition based reasons. Henrich argues that knowledge coming from high-status people, at least in hunter-gatherer societies, tended to be safer than knowledge from more directly measurable evidence. The cultural knowledge that accumulates over many generations aggregates information that could not be empirically acquired in a short time.

So Henrich implies it’s reasonable for people to be confused about whether evidence based medicine embodies more wisdom than eminence based medicine. Traditional culture has become less valuable recently due to the rapid changes in our environment (particularly the technology component of our environment), but cultures that abandoned traditions too readily were often hurt by consequences which take decades to observe.

I got more out of this book than a short review can describe (such as “How Altruism is like a Chili Pepper”). Here’s a good closing quote:

we are smart, but not because we stand on the shoulders of giants or are giants ourselves. We stand on the shoulders of a very large pyramid of hobbits.