Sunday, January 17, 2016

Book Review: The Secret of Our Success

Joseph Henrich begins his preface to The Secret of Our Success by going over how his path through academia led him to write this book.  He started out getting dual bachelor degrees in anthropology and  aerospace engineering.  He worked as an engineer for a while before going back to school for his doctorate in anthropology.  Luckily the math from his engineering background came in useful when he got interested in evolution, population genetics, and how the tools from population genetics could be applied to cultural transmission.  I don't think this book could have been written by someone without such a broad background.

It's easy to do a bad job talking about how evolution has influenced human behavior.  It's easy to find people bloviating with evolutionary explanations about the ways men and women act differently in our society.  But clearly you won't come to any success if the supposed human universal you're trying to explain is particular to the society we live in and a few others.

This book is deeply concerned with human universals because it's aim is to explain how our species became so successful at rapidly - at least compared to evolution - expanding through new biomes.  Even before agriculture or the industrial evolution humans could be found in far more biomes than any other large animal.  There is some set of traits that allows us to do this while our chimpanzee and bonobo cousins are limited to narrow ecological bands.

One of the major themes from the book was social learning and the way humans are good at it in a way that our nearest cousins, chimps and bonobos, aren't.  Humans can from a very young age employ much more sophisticated strategies for copying the behavior of others than other primate can even if chimpanzees are just as good at solving logic puzzles when they're three years old.  And humans copy much more rigorously leading to potentially much more sophisticated cultural evolution.

Here's an example from the book.  There's a plant that was cultivated widely in South America called the Manioc.  It caries a subtle poison in it's untreated from - killing people who consumer it slowly over a number of years.  If you soak mashed Manioc for a day you can remove the bitter flavor but if you soak it for three days you'll be able to remove enough poison that you can safely subsist on it.  In a sense Europeans are lucky in that the food they had to rely on, grain, had processing requirements that were transparent to the people preparing it.  This all makes me think that the lessons of Chesterton's Fence aren't really anything you have to talk about unless you happen to belong to a culture that explicitly praises inventiveness.

Another major difference between humans and chimps is the existence of social norms and the punishment of defectors.  There's something used in biology and anthropology called the ultimatum game.  In it there is a fixed amount of resources in play.  The first player proposes some division of the resources and the second accepts the division or refuses - in which case neither player gets anything.  The "economically rational" thing for the second player to do is to accept any deal that gives them anything since that makes them better off than before.  Chimps behave in the "rational" way but as you might expect humans don't.  I'd actually run into that result before this book and it really shook my belief in my previous view that humans became intelligent to complete with other humans.

There's a whole lot of interesting stuff like that in this book and it really shifted my views on what it means to be human.  There's more good stuff I haven't mentioned on developmental psychology, selective pressures on the sounds in language, and other stuff.  I sort of wish the author had added a degree in neuroscience to his other achievements but we can't have everything.  There's some other thoughts I've had on this on natural selection and complex adaptations but that'll be another blog post.

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