The one-handed economist

I first learned of Joseph Henrich when I read his jointly authored paper “In search of homo economicus: behavioral experiments in 15 small-scale societies” [pdf], which was published in economists’ top journal in 2001. The paper was impressive on two counts. First, it showed economists how anthropologists could use their field knowledge to explain behavior. Second, it undermined (yet again) economists who claimed to be describing “universal”  behavior. Henrich et al.  showed how culture affected human cooperation. Although some economists continue to ignore culture (one of my graduate school professors banned use of that word), those who spend time “among mere mortals” know that culture needs to be accounted for in their theories, analyses, and policy proposals.

It is for these reasons that I bought this 2015 book (subtitled: “How culture is driving human evolution, domesticating our species, and making us smarter”), which I’ll abbreviate as SOS. I wanted to learn more from a guy who asks useful questions and then does all he can to understand and explain the nuances to answering them.

I also want to note that I read this book after Yuval Hariri’s Sapiens, which I found to be insightful but slightly disappointing. (Others are more harsh.) I recommend Henrich’s SOS over Sapiens because it provides deeper insights and more useful ideas.

The secret, btw, is cultural evolution, i.e., how we learn, imitate and improve on ideas, not as individuals but members of a group. It’s from this source that we have language, abstractions, processes and rules-in-use (institutions) that help each generation do better than the last. (Henrich defines “culture” as “the large body of practices, techniques, heuristics, tools, motivations, values, and beliefs that we all acquire while growing up, mostly by learning from other people” Loc(ation) 239.)

For the rest of this review, I will summarize the ideas from SOS that appealed to me and give a few comments. As usual, these notes reflect my own perspective and learning. YMMV 🙂

1. Some paleo-anthropolgists claim that language differentiates humans  from other primates, but Henrich claims that it is our ability to teach and learn culture. Some primates can learn, communicate and use tools, but they are far worse than humans at these tasks. Data comparing babies to adult and juvenile chimpanzees shows that babies are orders of magnitude better at observing and learning from example.
2. “Once these useful skills and practices began to accumulate and improve over generations, natural selection had to favor individuals who were better cultural learners, who could more effectively tap in to and use the ever-expanding body of adaptive information available. The newly produced products of this cultural evolution, such as fire, cooking, cutting tools, clothing, simple gestural languages, throwing spears, and water containers, became the sources of the main selective pressures that genetically shaped our minds and bodies. This interaction between culture and genes, or what I’ll call culture-gene coevolution, drove our species down a novel evolutionary pathway not observed elsewhere in nature, making us very different from other species—a new kind of animal” Loc 252, emphasis added.
3. Humans added “prestige” as a second status that complements or substitutes for status via “dominance,” which animals also have. I think of prestige as wisdom and dominance as strength.
4. “Norms influence a vast range of human action, including ancient and fundamentally important domains such as kin relations, mating, food sharing, parenting, and reciprocity…Repeated norm violations sometimes provoked ostracism or even execution at the hands of one’s community. Thus, cultural evolution initiated a process of self-domestication, driving genetic evolution to make us prosocial, docile, rule followers who expect a world governed by social norms monitored and enforced by communities” Loc 282-4.
5. “Our collective brains arise from the synthesis of our cultural and social natures—from the fact that we readily learn from others (are cultural) and can, with the right norms, live in large and widely interconnected groups (are social)… we don’t have these 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” Loc 297, 319.
6. “(N)atural selection made us highly social and cooperative… by working together we conquered the globe” Loc 403. Unfortunately, we seem to have scaled up by too much, as we now lack the cultural or social tools to rein the behaviors that are driving climate change, destroying biodiversity, and thus threatening 100,000 years 2 million years of collective success.
7. “Social learning refers to any time an individual’s learning is influenced by others… Individual learning refers to situations in which individuals learn by observing or interacting directly with their environment and can range from calculating the best time to hunt by observing when certain prey emerge, to engaging in trial-and-error learning with different digging tools…Cultural learning refers to a more sophisticated subclass of social learning abilities in which individuals seek to acquire information from others, often by making inferences about their preferences, goals, beliefs, or strategies and/or by copying their actions or motor patterns…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…we humans are rather inclined to copy—spontaneously, automatically, and often unconsciously. Chimpanzees don’t appear to suffer from this cognitive “bug,” at least not nearly to the same degree” Loc 424-564, emphasis added. Humans are worse at game theory than chimps [the real homo economicus!], but humans are much better at learning by imitation, which is an advantage when learning complex processes or concepts.
8. This skill has its downsides. We learn by copying, and copy more from those with success and prestige. This system works on a small scale as a means of transmitting cultural knowledge, but its remnants fail in today’s world of social media, where people “follow” without any feedback from influencers and copy visible aspects of success without also copying the many hidden steps that led to success. (It also explains the much older practice of paying celebrities to advertise products. Consumers who trust their prestige do not ask questions about the product’s quality.)
9. “Culture, and cultural evolution, are then a consequence of genetically evolved psychological adaptations for learning from other people. That is, natural selection favored genes for building brains with abilities to learn from others” Loc 808.
10. “Students may learn more effectively from teachers or professors who match them on these dimensions [sex and ethnicity], which may impact a person’s grades, choice of major, or career preferences…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” Loc 1036-44.
11. “Copying suicide highlights the potency of our imitative tendencies and means that under the right conditions we can acquire practices via cultural learning that natural selection has directly acted to eliminate under most conditions. If humans will imitate something that is so starkly not in our self-interest, or that of our genes, imagine all the other less costly things we are willing to acquire by cultural transmission” Loc 1120.
12. “You first need to acquire the social norms and rules governing the world you are operating in, and only then is strategic thinking useful. In our world, successful Machiavellians must first be skilled cultural learners. You can’t bend, exploit, and manipulate the rules until you first figure out what the rules are” Loc 1159.
13. Although our individual ancestors might have been smarter or better skilled at survival than we are (when’s the last time you caught your dinner in the wild?), we are more successful because we can draw on the cumulative cultural experiments and adaptions of our ancestors, some of whom died in ways that help us avoid similar death today.
14. “Childhood is a period of intensive cultural learning, including playing and the practicing of adult roles and skills, during which time our brains reach nearly their adult size while our bodies remain small. Adolescence begins at sexual maturity, after which a growth spurt ensues. During this time, we engage in apprenticeships, as we hone the most complex of adult skills and areas of knowledge, as well as build relationships with peers and look for mates” Loc 1309.
15. Cooking, food processing and tools allowed our energy-intensive brains to grow larger and more sophisticated. Our bodies also evolved for hunting, throwing and digesting cooked food. The same processes explain why we sweat to cool ourselves off: we do not need to fear dehydration because we learned to find, store and carry water. 
16. “Blue and green eyes are a side effect of natural selection favoring genes for lighter skin among cereal-dependent populations living at high latitudes. If cultural evolution hadn’t produced agriculture, and specifically techniques and technologies suitable for higher latitudes, then there would be no blue or green eyes. In all likelihood then, this genetic variant only started spreading within the last six millennia, after agriculture arrived in the Baltic region” Loc 1703.
17. “Humans reliably develop emotions and motivations to seek out particularly skilled, successful, and knowledgeable models and then are willing to pay deference to those models in order to gain their cooperation (pedagogy), or at least acquiescence, in cultural transmission. This deference can come in many forms, including giving assistance (e.g., helping with chores), gifts and favors (e.g., watching their children), as well as speaking well of them in public (thus broadcasting their prestige). Without some form of deference, prestigious individuals have little incentive to allow unrelated learners to be around them and would not be inclined to provide any preferential access to their skills, strategies, or know-how” Loc 2339.
18. “Both dominant and prestigious men tended to get their way at group meetings, but only prestigious men were respected and generous… Dominant individuals tended to (1) act overbearing, (2) credit themselves, (3) use teasing to humiliate others, and (4) be manipulative. Meanwhile, prestigious individuals (1) were self-deprecating, (2) attributed success to the team, and (3) told jokes” Loc 2403, 2469.
19. “Saint Ambrose, the archbishop of Milan, made giving to the poor admirable. Rich Christians began to compete to see who could give the most to the poor (often through the church), inspired by paragons like Ambrose, who gave all their wealth away. Prior to this, giving to the poor was puzzling (at best) since the poor had little or nothing to give back. This move may have been crucial to the long-run success of the Church as an organization (and, no doubt, the poor appreciated it too). For the same reason, charitable organizations open their efforts to raise money by featuring donations from highly prestigious individuals, whose generosity is subsequently made known…by behaving altruistically, and because they are role models for others, prestigious individuals can increase the overall prosociality of their local groups or their sections of the social network. This, of course, means that any altruism is only altruism in the short-term sense. In the longer run, prestigious individuals who behave generously get to live in a social network that, by virtue of their own actions, becomes more generous and cooperative” Loc 2546, 2562.
20. “If the elderly are so often prestigious across human societies, why aren’t they particularly admired or respected in many Western societies? To answer this, we return to the evolutionary logic. The aged are accorded prestige and deference when more decades of experience and learning can provide a proxy measure for accumulated knowledge and wisdom. However, if a society is rapidly changing, then the knowledge accumulated by someone over decades will become outdated rather quickly” Loc 2630.
21. “The Great Sanhedrin, the ancient Jewish court and legislature that persisted for centuries at the beginning of the Common Era. When deliberating on a capital case, its seventy judges would each share their views, beginning with the youngest and lowest-ranking member and then proceed in turn to the “wisest” and most respected member. This is an interesting norm because (1) it’s nearly the opposite of how things would go if we let nature take its course, and (2) it helps guarantee that all the judges got to hear the least varnished views of the lower-ranking members, since otherwise the views of the lowest-status individuals would be tainted by both the persuasive and deferential effects of prestige and dominance” Loc 2732.
22. “Social norms about sexual fidelity mean not only that the husband is monitoring his wife’s sexual and romantic life, but so is the rest of the community, making it much tougher for the wife to behave in ways that might lower the husband’s confidence that his wife’s children are indeed his children. This has a psychological impact on the husband, motivating him to invest more in his wife’s offspring (because they are more likely to be his). Wives also know that if they are caught violating fidelity norms (e.g., having sex with someone else), it will influence their reputation with people well beyond their current husband and his kin” Loc 2902.
23. College life? “Perhaps even more enduring and powerful than synchrony are the potent social bonds forged among those who share terrifying experiences. Such experiences have been routinely created in different ways by male initiation rites in societies across the globe and throughout history…Being in a ritual relationship, while holding genetic relatedness constant, is strongly associated with sharing meat and information, as well as receiving help when one is sick or injured. These culturally constructed ritual relationships are much more important than close genetic relatedness” Loc 3188, 3242.
24. In experiments, I found that cooperation within a group rises when it is competing with other groups: “Intergroup competition provides one important process that can help explain the spread of norms that foster prosociality. Different groups culturally evolve different social norms. Having norms that increase cooperation can favor success in competition with other groups that lack these norms. Over time, intergroup competition can aggregate and assemble packages of social norms that more effectively promote such success, and these packages will include social norms related to cooperation, helping, sharing, and maintaining internal harmony” Loc 3300.
25. … and that cooperation will fade if its raison d’être disappears: “prosocial institutions age and eventually collapse at the hands of self-interest, unless they are renewed by the dynamics of intergroup competition. That is, although it may take a long time, individuals and coalitions eventually figure out how to beat or manipulate the system to their own ends, and these techniques spread and slowly corrode any prosocial effects” Loc 3354.
26. But these people defectors also put themselves at risk: “In small-scale societies, as in many communities, the sanctioning of norm violators begins with gossip and public criticism, often through joking by specific relatives, and then intensifies to damage marital prospects and reduce access to trading and exchange partners. If violators are still not brought into line, matters may escalate to ostracism or physical violence (e.g., beatings) and occasionally culminate in coordinated group executions…perpetrators can only get away with such actions when they target a norm violator, a person with his reputational shield down. Were they to do this to someone with a good reputation, the perpetrator would himself become a norm violator” Loc 3675, 3691. This passage reminds me of the grim scene in Zorba the Greek, where the young widow is killed after a suitor commits suicide, because she was “too seductive” for the men of the village.
27. “Why would natural selection have built us to be norm internalizers? Broadly speaking, internalizing motivations helps us to more effectively and efficiently navigate our social world, a world in which some of the most frequent and dangerous pitfalls involve violating norms. Such motivations may help us avoid short-term temptations, reduce cognitive or attentional loads, or more persuasively communicate our true social commitments to others” Loc 3853. Norms, in other words, help us cooperate in producing and protecting the collective goods that contribute to define group prosperity. If you compare successful to failing communities and states, you will see that they mainly differ in the presence or absence of such institutions.
28. “The psychological machinery that underpins how we think about “race” actually evolved to parse ethnicity, not race. You might be confused by this distinction since race and ethnicity are so often mixed up…when children or adults encounter a situation in which accent or language indicate “same ethnicity” but skin color indicates “different race,” the ethnolinguistic markers trump the racial markers” Loc 3996, 4003. I’ve written about misplaced racism.
29. Why are so many people engaged in culture wars without a concern for the feelings or future of their neighbors? Too much prosperity. “By strengthening prosocial group norms, the experience of war resulted in more, and more energized, community organizations. Why would war have these prosocial effects? During hundreds of thousands of years, intergroup competition spread an immense diversity of social norms that galvanized groups to defend their communities; created risk-sharing networks to deal with environmental shocks like drought, floods, and famines; and fostered the sharing of food, water, and other resources” Loc 4056.
30. Sapiens with individually smaller brains beat Neanderthals with individually larger ones because they created a hive mind: “Once individuals evolve to learn from one another with sufficient accuracy (fidelity), social groups of individuals develop what might be called collective brains. The power of these collective brains to develop increasingly effective tools and technologies, as well as other forms of nonmaterial culture (e.g., know-how), depends in part on the size of the group of individuals engaged and on their social interconnectedness… Larger populations can overcome the inherent loss of information in cultural transmission because if more individuals are trying to learn something, there’s a better chance that someone will end up with knowledge or skills that are at least as good as, or better than, those of the model they are learning from… by acquiring distinct elements from different people, learners can create “innovations” without “inventions”; that is, by recombining things copied from different models, novelties can emerge without individuals themselves thinking up a new technique on their own. This process turns out to be crucial for understanding innovation” Loc 4134, 4204, 4277.
31. “Languages are cultural adaptations for communication. These communication systems had to adapt (culturally) to our brains, exploiting features of our ape cognition, and at the same time, created new selection pressures on our genes to make us better communicators. These genetic evolutionary pressures were powerful, shaping both our anatomy and psychology: they pushed down our larynx to widen our vocal range, freed up our tongues and improved their dexterity, whitened the area around our irises (the sclera) to reveal our gaze direction, and endowed us with innate capacities for vocal mimicry and with motivations for using communicative cues, like pointing and eye contact…cultural evolution is a key reason why existing languages are so easily learned by children, and some of the recurrent features of languages, like syntax, are likely the result of cultural evolution working to keep languages learnable, especially as vocabularies expand” Loc 4494, 4883.
32. That said, language did not make humans unique: “(1) quite a bit of cultural transmission and cultural evolution is possible without language. Cultural information about tool manufacture, fire making, dangerous animals, edible plants, cooking, and diet (food choice) can all be acquired…(2) language itself is a culturally evolved product, so it can’t cause culture… (3) language has at its core a rather serious cooperative dilemma: lying, deception, and exaggeration. Lying with language is cheap, at least in the short term, and is a potentially powerful way to exploit and manipulate others…Thus, for complex communicative repertoires to evolve in the first place, this cooperative dilemma has to have already been at least partially solved” Loc 5001-18.
33. West is best different: “People from different societies vary in their ability to accurately perceive objects and individuals both in and out of context. Unlike most other populations, educated Westerners have an inclination for, and are good at, focusing on and isolating objects or individuals and abstracting properties for these while ignoring background activity or context. Alternatively, expressing this in reverse: Westerners tend not to see objects or individuals in context, attend to relationships and their effects, or automatically consider context. Most other peoples are good at this” Loc 5229.
34. Henrich spends some pages describing his theory for how humans got going, in terms of cultural-genetic evolution. I will not summarize that process, but I’ll tempt you with its start: “In many primates, such as chimpanzees, female bodies unmistakably signal when they are sexually receptive and capable of getting pregnant, sometimes using shiny buttock swellings. This means that once a male has hung around a female long enough, he’ll know her cycle, and thus know when it’s safe to head off to find some more receptive females or build alliances among males. In humans, however, females are potentially sexually receptive all the time, and males cannot reliably predict when their mate can get pregnant. So, by concealing ovulation at least partially, males are forced to be around their mates more often than they would otherwise and end up engaging in a lot of reproductively unnecessary sex. As a by-product, this extra “hanging around” his mate will further solidify his relationships with any offspring who are hanging around their mother” Loc 5904. In the pages that follow, he links hanging around to the growth of clans, sexual division of labor, and collective brains: “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” Loc 6239.
35. And thus we arrive at the secret of our (varying) success: “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 the 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. Achieving this depends on people’s psychology, which arises from a package of social norms and beliefs, along with the formal institutions they foster or permit” Loc 6283.

Bottom Line: I strongly recommend this book for its deep and interesting explanations for how we got here as a species, how we behave and cooperate today, and how to understand the various pushes and pulls of our social and cultural institutions.

Here are all my reviews.