Sunday, October 02, 2016

The Secret of our Success, by Joseph Henrich

Joseph Henrich's The Secret of Our Success has a fair amount of overlap with Herculano-Houzel's The Human Advantage, which I reviewed in July. Both spend most of their attention on explaining why humans, of all the products of evolution, turned out to be the smartest and hence dominant species on the planet. The Human Advantage focused on what makes the human brain unique, and found some surprising neuronal traits that sets mammals apart from other other animals, and that make primates unique among mammals in their neuronal architecture. Henrich, on the other hand, takes pains to point out that individual humans (even very smart ones) aren't very good at figuring out how to survive in new environments. He uses that evidence to argue that communication and culture make the difference. As individuals, he claims, we aren't much smarter than other primates.

They both agree that cooking was a huge step forward for us, but Henrich takes pains to point out that this only an advantage when we're raised in a cultural group. Unlike practically all other animals, we don't instintively know how to unlock the nutrition in common foodstuffs—without training, it would take a long time (during which you have to be subsisting on something else) to figure out how to prepare most of what we eat.

The book starts out with several stories about lost european explorers becoming stranded, and if they didn't get help from locals, they would starve in the midst of what the locals would consider plenty. In Australia, the Arctic, and Florida, well-funded and trained explorers slowly starved because they couldn't figure out how to find, harvest, or prepare the foods the locals subsisted on, and they either didn't think to ask for help, or they drove away those who tried to help them. In contrast, there are a couple of stories of individual aborigines who are separated from their kin, and do just fine for years, since they grew up gathering and preparing the local bounty. His point is that our strength, as a species, is learning from one another, and picking up on every small increment in survivability.

I've been saying for years (since reading Jared Diamond's Guns, Germs, and Steel) that the thing to realize about the spread of humans and their ability to make use of local flora and fauna is that there were enough people, and people are curious enough that we tried to exploit everything, and we tried to make use of everything available in all conceivable ways. How else to explain the fact that people ate acorns, seal livers, and nardoo. In preparing nardoo, the Australian aborigines grind seeds, leech them with water, mix them with ash during heating, and use mussell shells to serve them. If you miss any step, then like the explorers, you'll die of poisoning or stavation with a full belly.

Along the way, this book has lots of interesting proposals about how culture affects prestige and dominance in ways that make it possible for us to live in larger groups and take advantage of the skills and abilities of more people; how competition for living space between groups leads to cultural differences, and how our ability and drive to share culture and learn from each other leads to increasing communication abilties and common grammar strength across the species. There are interesting tidbits spread throughout.

In talking about how living in larger groups with a larger repertoire of tools and techniques make us more capable without requiring more individual smarts or inventiveness, Henrich gave a list of simple tools that is more interesting than the standard list of 6 simple machines known since antiquity:

wheels, pulleys, springs, screws, projectiles, elastically stored energy (e.g. bows, spring traps), levers, poisons, compressed air (blow guns), rafts, leisters [a barbed spear], and heating (fire and coooking).
Instead of focusing on mechanical advantage as we do with the simple machines, this focuses on shared, reusable knowledge, and shows that there were ideas around to be re-used even in societies that were very primitive by modern standards.

Henrich has a longer more detailed time-line than Herculan-Houzel, and his focuses on evidence about tool use showing accumulation of culture rather than archeological evidence relating to brain size, cooking, and gut size. I enjoyed this book as much as Human Advantage, and it added an interesting, non-conflicting story about the roots of our intelligence. It didn't feel as if it has as much relevance to the question about our place in the universe—once we set out on the path toward communication and shared culture, Henrich didn't mention further roadblocks toward increasing advantage as we exploited the new niche better.