“…we don’t have tools, concepts, skills, and heuristics because our species is smart; we are smart because we have culturally evolved a vast repertoire of tools, concepts, skills, and heuristics. Culture makes us smart.” 7
Henrich argues that culture has become the primary driver of human genetic evolution. The effects of culture on our genetic makeup, combined with the cultural adaptations themselves, have allowed humanity to dominate the globe. The abilities and intelligence of particular individuals are relatively limited and comparable to other primates, but culture and our predisposition for cultural learning allow us to access a collective brain that finds solutions to survival challenges that no individual could discover alone.
Henrich describes how cultural evolution bootstrapped its way into becoming a primary evolutionary driver. He believes that a number of factors led to the development of culture, including bipedalism, hand anatomy, human fragility with regard to predators, which prompted tribal living and pair-bonding. Once cultural groups formed, those able to access the collective brain will have greater reproductive success. Furthermore, the selective pressures of culture made us better purveyors and leaners of culture; we unknowingly domesticated ourselves to live inside of cultural groups.
Evidence for the book’s argument comes from a very broad and entertaining number of sources: linguistics, anatomy, lab research with humans and other primates, archeology, anthropology, genetics, mathematical modeling, and history. For me the most interesting sections were about European explorers who died because they could not discover the cultural adaptations that allowed native people to survive in the harsh environments of the Arctic or Australia. Even well-equipped teams of trained explorers could not survive in these climates, unless they were aided by native groups or were able to use some of their cultural tools. I also really enjoyed descriptions of laboratory simulations of cultural evolution that demonstrated how larger groups are able to generate and pass on innovations in ways that smaller groups cannot.
The book is quite dense and in some stretches a little hard to read and understand. The writing is generally very clear, but not always enjoyable or nimble. It’s also somewhat long. I would highly recommend the author’s Google Talk on the book.
It was easier for me to understand this book having read Susan Blackmore’s The Meme Machine. She outlines a similar vision of how cultural practices or behaviors (memes) could have become an evolutionary pressure. Blackmore actually goes further, to argue that memes are now evolving separately from humans, and are in fact using humans as a means of reproduction. I don’t think Henrich would agree, but the commonalities between their views made comprehending his book easier.
Ideas per Page:1 8/10 (higher) the general argument is somewhat simple, but the evidence he musters sometimes requires explanation, and you learn about many interesting peripheral issues along the way.
Related Books: The Meme Machine by Susan Blackmore, Why Information Grows by Cesar Hidalgo,
Recommend to Others: Yes, if interested in evolution and are not afraid of dense books
Reread Personally: no
“…these findings suggest that the only exceptional cognitive abilities possessed by young children in comparison to two other great apes relate to social learning, and not to space, quantities, or causality.” 14
“Our species’ uniqueness, and thus our ecological dominance, arises from the manner in which cultural evolution, often operating over centuries or millennia, can assemble cultural adaptations. In the cases above, I’m emphasized those cultural adaptations that involve tools and know-how about finding and processing food, locating water, cooking, and traveling. But as we go along, it will become clear that cultural adaptations also involve how we think and what we like, as well as what we can make.” 33
“..being taught by instructors whom you match on ethnicity/race reduces your dropout rate and raises your grades. In fact, for African-American students at a community college, being taught by an African-American instructor reduced class dropout rates by 6 percentage points and increased the fraction attaining a B or better by 13 percentage points.” 46
“…about 2 million years ago, we first crossed this evolutionary Rubicon, at which point cultural evolution became the primary driver or our species’ genetic evolution. This interaction between cultural and genetic evolution generated a process that can be described as autocatalytic, meaning that it produces the fuel that propels it.” 57
“In short, while being otherwise nearly helpless, babies and toddlers are sophisticated cultural learning machines.” 65
“Thus, cheese and yogurt making are, at least in part, cultural adaptations for reducing lactose, which permit everyone to access much of the otherwise unavailable nutrition from milk. If populations had developed these bodies of technical know-how too soon, the selection pressure for on genes for doing the same job would have been weakened.” 90
“Thus, the unwillingness of the mother to take on faith the practices handed down to her from earlier generations would result in sickness and early death for members of her family. The problem is that the steps in this procedure are causally opaque—an individual cannot readily infer their functions, interrelationships, or importance.” 99
“The point here is that cultural evolution is often much smarter than we are. Operating over generations as individuals unconsciously attend to and learn from more successful, prestigious, and healthier members of their communities, this evolutionary process generates cultural adaptations.” 99
“If a hunter shows any bias to return to previous spots, where he or others have seen caribou, then the caribou can benefit (survive better) by avoiding these locations. Thus, the best hunting strategy requires randomizing. Can cultural evolution compensate for our cognitive inadequacies?” 105 [people used divination to randomize hunting locations] [in tropical climates people use heavy spice, which is anti-microbial]
“In parallel with how wolves were domesticated into dogs by killing those that wouldn’t obey and refused to be trained, human communities domesticated their members.” 188
“Ethnic-group membership is assigned based on culturally transmitted markers, like language or dialect. By contrast, racial groups are marked and assigned according to perceived morphological traits, like skin color or hair form, which are genetically transmitted.” 205
“However, remember that our species’ ability to live in large groups, well beyond residential populations, still depends heavily on social norms.” 214
“My point: words are like other aspects of culture, and consequently we should expect the vocabulary sizes of languages to expand with a population’s collective brain. As both color terms and integers illustrate, such additions are not merely incidental, but may give us new cognitive abilities and raise our IQs.” 243
“The potential for such manipulative cultural transmission would have created a selection pressure for learners to look for what I call CRedibility Enhancing Displays (CREDs). CREDs are actions that a person would be unlikely to perform if he or she believes something different from their verbally stated preferences.” 258 [costly, hard-to-fake signals]
“Recent evidence clearly shows how culture can shape biology by altering our brain architecture, molding our bodies, and shifting our hormones. Cultural evolution is a type of biological evolution; it’s just not a type of genetic evolution.” 263
“Generating and sustaining technological complexity requires collective brains linked by social networks and galvanized by social norms.” 293
“Once we understand the importance of collective brains, we begin to see why modern societies vary in their innovativeness. It’s not the smartness of individuals or formal incentives. It’s the willingness and ability of large numbers of individuals at the knowledge frontier to freely interact, exchange views, disagree, learn from each other, build collaborations, trust strangers, and be wrong. Innovation does not take a genius or a village; it takes a big network of freely interacting minds.” 326
1 A measure of the number of new or distinct ideas introduced per page. 10/10 would be conceptually dense, like a textbook. 1/10 would be almost completely fluff.