This post is about the recent book The Secret of our Success: How Culture is Driving Human Evolution, Domesticating our Species and Making Us Smarter, by Joseph Henrich, Princeton Press, 2016. For me this is an extremely important book since I think that what Henrich is doing is right at the cutting edge of contemporary anthropology and behavioral biology.
The main idea of this book is that the real reason for the tremendous success of the human species is not so much our rationality, or our special intelligence, or that we are the special chosen creatures of creation. Henrich, and suddenly a lot of other scientists, are saying that the secret of our success is that humans have the ability to acquire and to use highly evolved cultural systems which enable us to achieve infinitely more than one individual ever could manage alone.
The innate, natural abilities of single human beings is pretty insignificant. Individual human beings, like many of the shipwrecked and other wise marooned explorers of the 19th century and earlier, who are forced to rely on only their innate, built in strengths find it impossible to survive in new strange cultures, much less create great and powerful civilizations. I will have more to say about these marooned explorers later in this essay.
Humans are not only the result of biological or genetic evolution but also of cultural evolution. Human cultural evolution is basically our collective brains, the ability of human individuals to socially interconnect and to learn from each other over generations.
This is something that has been going on for a very long time. Our prehistoric ancestors learned from each other and produced many early cultural innovations such as fire, cooking, water containers, and projectile weapons. These cultural innovations influenced our brains and even our bodies and genes in all kinds of critical ways. And then later in human history our collective brains created even more powerful ideas such as the lever, the wheel the screw and eventually writing. All of this is part of our cultural heritage that allows to be far smarter than we ever could be individually.
Henrich says that our genes and our biology are inextricable interwoven with cultural evolution and that this culture-gene interaction launched our species on an extraordinary evolutionary path. The evolution of our cultural and social and physical natures at one and the same time produced a collective intelligence that explains our success as a species and also our human uniqueness.
Henrich had a very different educational background. He is one of the new breed of scientists who are equally at home in a number of disciplines which had previously been thought completely separate.
He started out as in aerospace engineering with a strong background in mathematics and engineering. He also graduated with a minor in anthropology. After graduating he worked at Martin Mairietta for several years as an engineer but soon realized that this was not what he wanted to spend his life doing. So he went back to school at UCLA and got a Masters and then a PhD in anthropology.
At this point, he decided he really didn’t know much so he took a year off just to read. He spent his year reading cognitive psychology, decision making (which is now part of cognitive psychology,) experimental economics, biology and evolutionary psychology. He read all of Daniel Kahneman and Amos Tversky, the pioneers in the field of human cognitive bias.
From the beginning, Henrich wanted an interdisciplinary view so that he could integrate ideas across the social and biological fields. He wanted to build an evolutionary approach to human psychology and behavioralism that takes seriously the cultural nature of our species. In the middle of all of this he married Natalie Smith who was a graduate student in archeology and who was working on ideas about human cooperation. Natalie continues to be not only his wife but the other side of a lifelong discussion of human psychology and biology.
All this was happening in the middle and late 1990’s. Suddenly the whole field that he was interested in began to explode. A whole group of disciplines began to flow together into one new discipline. Ethnography (the study of the customs of both individual people and entire cultures) + behavioralism + biology + economics + sociology, + psychology + genetic evolution + game theory + cultural evolution all began to look like they were pretty much a single discipline. Heinrich was in on the beginnings of this intersection of what were previously thought of as separate ways of looking at the world.
Now, twenty-five years later, he says that he is writing this book as “a waymark, as a work in progress” of this whole movement. He says that “He is convinced that to understand our species we need to build a science of human behavior and psychology and we need to begin with an evolutionary theory of human nature.” He says that getting this first step right is very imporatant.
Heinrich says that he is very encouraged by the 2015 World Bank book, “World Development Report 2015: Mind, Society, Behavior.” By clicking the link to the left, you can buy or get a sample of this report from Amazon Kindle. This book articulates a lot of Heinrich’s basic ideas as it discusses the central role of culture in the evolution of humans and human society.
Chapter 1, “A Puzzling Primate”
The first chapter of Heinrich’s book, “A Puzzling Primate” is a fascinating discussion of the fact that even though humans have dominated all of the eco -systems of the earth, yet individually they are very inept. Our in-born, innate characteristics are just not very impressive. We have big brains, but humans individually are not terrible bright, not smart enough to explain the immense success of our species. Heinrich says that we definitely would not win a survival game with a bunch of capuchin monkeys if we were both parachuted into the central African jungle.
The secret of our species success is not our raw, innate intelligence. Stripped of our culturally acquired mental skills we are a very unimpressive species. In what Heinrich calls the survivor game, where humans are isolated alone in an alien enviroment, humans always die, or are rescued by some local, indigenous people. The reason the humans always die is that humans have evolved an addiction to our particular culture. And without all the trappings of our culture we are helpless.
By culture, Heinrich means all of the practices, techniques, heuristics (intellectual shortcuts), tools, motivations, values and beliefs we acquire while growing up.
The key to understanding why humans are so different from other species is to see that humans are a cultural species. Over a period of a million years humans began learning from each other in such a way that culture became cumulative. This is the opposite of innate or inborn. Humans alone with only what they are born with are helpless and weak. Culturally we are the most powerful species on earth. Culture is what has made us what we are, not reason. Our innate thinking machinery is full of biases and actually works very poorly.
After a number of generations in prehistory, the process of building cumulative knowledge gave us a tool kit of practices and techniques that individuals could never figure out alone in a single lifetime. And natural selection figured into this process also. For example, natural selection favored individuals who were better cultural learners. This interaction between culture and genes is called culture-gene coevolution. This drove our species down a novel evolutionary pathway not seen anywhere else in nature and has made us a very special species.
Man’s capacities for learning are carefully honed by natural selection. All of us automatically and unconsciously learn from others, from culture based on cues of prestige, success, skill, sex, and ethnicity. Culture evolves invisibly as our attention and learning biases shape what we pay attention to, remember and pass on. And our acquired cultural knowledge interacts with genetic evolution that has shaped and continues to shape our anatomy, physiology and psychology. This is what drives the rapid expansion of our brains. Cultural evolution and genetic Evolution come first and big brains come second.
This combined cultural-genetic evolution has selected our big brains, long childhoods, and long post-menopausal lives. We are who we are because the genes for big brains, long childhoods, and long post-menopausal lives were selected for. And we have adapted to our culture, genetically–our culture has ended up changing our genes and tour bodies and our brains. As Henrich says,
“Anatomically and physically, the escalating need to acquire this adaptive cultural information drove the rapid expansion of our brains, giving us the space to store and organize all this information, while creating the extended childhoods and long postmenopausal lives that give us the time to acquire all this know-how and the chance to pass it on.
Along the way, we’ll see that culture has left its marks all over our bodies, shaping the genetic evolution of our feet, legs, calves, hips, stomachs, ribs, fingers, ligaments, jaws, throats, teeth, eyes, tongues, and much more. It has also made us powerful throwers and long-distance runners who are otherwise physically weak and fat.”
We have come to rely so completely on cultural evolution for our survival that we now put more faith in what we learn from our communities and than from our individual experiences. What we learn from culture is smarter than we are individually.
As Henrich says, “The secret of our species’ success resides not in the power of our individual minds, but in the collective brains of our communities. 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). The striking technologies that characterize our species, from the kayaks and compound bows used by hunter-gatherers to the antibiotics and airplanes of the modern world, emerge not from singular geniuses but from the flow and recombination of ideas, practices, lucky errors, and chance insights among interconnected minds and across generations.”
Our cultural natures allow us to learn from others and our social Nature allows us to live in widely interconnected groups. All of our great human technology from kayaks and Compound bows come not from isolated geniuses but from cumulative insights of many others.
Innovation in our species comes more from our sociality then from our intellect. The real challenge has always been how to prevent communities from fragmenting and social networks from dissolving. Much of the power and elegance of our language come from cultural and genetic evolutlion. Languages are products of cultural evolution.
Cultural Evolution drove the genetic pressures that drove the development of the Human larynx. All of these products of cultural Evolution do make us individually smarter also. But we don’t have all the tools and hueristics and skills because our species is smart. We have them because we have culturally evolved a vast repertoire of tools, concepts, skills and hueristics from our culture. Culture makes us smart not vice versa. We all got a massive cultural download while we were growing up.
Chapter 2, “It’s not our Intelligence”.
The Human species dominates the earth totally. We alter the earth and the rivers. We cycle more nitrogen than all other life combined. We use 100 times more biomass than any other large species that ever lived.
We caused the extinction of much of the Earth’s megafauna: mammoths, mastodons, etc. The disappearance of much megafauna coincides with the arrival of humans on certain islands and continents. This happened in Australia 6000 years ago. We killed 88% of the Australian big vertebrates. We killed 75% of the megafauna in America when we arrived. The same thing happened in Madagascar, New Zealand and in the Caribbean.
Humans appear to be weak and helpless but our cooperative social norms make us a top predator. It’s not just our present day industrialized society that make us so dangerous and destructive. We have been this way for a million years.
Other species have had ecological success also but this has mostly happened by speciation, that is, natural selection has adopted and specialized organisms to survive in certain environments. Ants, for example capture an equivalent biomass as that of humans. Ants are the most dominant invertebrates. Humans however remain a single species while ants have 14,000 different species.
Humans have almost no genetic variation yet we occupy a huge range of environments. We succeed because we can manufacture locally appropriate tools, weapons, and shelters. Also it is because humans cooperate intensively and exist in all kinds of social organizations, from families, to small bands, to tribes, to societies of thousands. Just considering hunter-gatherers, humans have more forms of social organization than the rest of the primates combined.
The question becomes why do only humans do this? The old answer is that we are more intelligent, we have bigger brains, more cognitive processing power, more memory, and better problem solving. We think we are intellectually better at solving problems than other species.
In the past there have been three common explanations of why humans are so successful: 1. We have better mental processing. 2. We have special mental abilities that evolved for survival in our hunter-gatherer past. 3. We have cooperative instincts and social intelligence that permit high levels of cooperation.
Henrich says none of these approaches can explain our success without first recognizing that humans have a large body of culturally transmitted information that no single individual or group is smart enough to figure out in a single lifetime. In other words it is cumulative cultural information that makes humans different and special and such a powerful species.
To understand human nature and our ecological dominance we first need to explain how cultural evolution gives rise to all kinds of adaptive practices, beliefs and motivations.
We are not nearly smart enough to account for our huge ecological success. Much of our seeming intelligence does not come from raw brainpower or a plethora of instincts. They come from an accumulated repertoire of mental tools, skills, concepts and categories.
There has been a lot of research done that pretty conclusively proves that humans minds and not more intellectually powerful than those of animals. Scientists have often compared mental abilities of humans to chimps and orangutans. Human children, rather than human adults, are often compared to apes because children have very little cultural knowledge. If adults are tested against chimps, the humans cumulative cultural knowledge absolutely demolishes the chimps, as would be expected.
Michael Tomasello, who is an American developmental and comparative psychologist and co-director of Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has done a lot of experimental work in this field. His work shows that there is no difference between chimps and two-and-a-half-year-old humans in raw intelligence. They have the same raw intelligence. Chimps are a little better than human children in tool use. However children are hugely better than chimps in social learning. Most human children score 100% in social learning and chips score 0%.
Human children and chimps score equally on space, quantity, causality, tests. Children totally defeat chimps on social learning. It doesn’t matter that we are comparing very young kids to older apes. Older apes are not smarter than younger apes.
Working memory and information processing speed are considered two of the foundations of intelligence. Both of these are associated with better problem solving and inductive reasoning. In working memory, chimps and humans often tie or chimps do a little better. The Chimps are much better at information processing speed. (The test was to arrange random numbers in proper order.) There are pro and con arguments here, but the point is that human intelligence did not massively dominate that of chimps.
In games of strategy, apes are far more rational than humans. They figure out how to win at strategy games very quickly, far more quickly than humans. Chips are 7 times more rational than humans in this regard. Humans don’t tend to learn thru rationality. Humans mostly learn through copying and imitating. This makes them less rational. Humans actually have a cognitive bug that makes them irrational, but good at processing cultural knowledge.
Humans are an intelligent species but not nearly intelligent enough to account for our huge ecological success. There is a vast literature in psychology and economics that shows that humans constantly make systematic, logical errors. Humans are predictably irrational. The books of Dan Kahneman and xx and xx have illustrated this point over and over again.
What Henrik and the behavioral economists and the cognitive scientist are saying is that man is not innately rational. His natural thinking and decision-making tools are flawed and biased in a very predictable ways. This is why Behavioral Science is used for advertising. Humans can be immensely intelligent but they don’t achieve this by using their superior brains, they do this by using their cumulative cultural knowledge.
Our thinking skills are really not much better than those of other species. We fall for the gambler’s fallacy, for the Concord or sunk cost fallacy, and the hot hand fallacy. Animals don’t fall for any of these fallacies.
Chapter 3, The Lost European Explorers,
Chapter 3, The Lost European Explorers, is a particularly interesting chapter.
Sir John Franklin was sent to find the Northwest Passage in 1845 with huge amounts of Western technology. Unfortunately he and his crew got frozen in the arctic ice for nineteen months and since it looked like it might be there forever, they abandoned their technologically equipped ship to live on King William Island.
All of the explorers gradually died after cannibalism failed to provide enough food to sustain them. On the other hand, the local Inuit Indians knew how to survive in the same location using their own cumulative cultural heritage. The Inuits thought the same territory was a rich source of food, clothing and shelter. The Inuits had lived here for thirty thousand years perfectly well. The white man’s big brains didn’t help them to survive a bit. They were a close-knit social group, but even this didn’t help them.
The reason Franklin’s men all died is that humans don’t adapt to new environments the way other animals do. In this situation all of their innate human intelligence was completely worthless. The white men’s big brains were no help in figuring out how to build composite bows or 3-prong fish beers or kayaks or igloos. The Inuit had 30,000 years of cultural knowledge which was incredibly vast and complex. To survive in the Arctic you need to know far more than one man can discover or learn in one lifetime.
Two other groups of European explorers were also stranded on King William Island and they did survive. How? John Ross’s crew of twenty-two men survived because they befriended the Inuits and the Inuits taught the white men survival skills. The natives transmited some of their cultural knowledge to the white men.
Another explorer, Roald Amundsen was the first European to find the Northwest Passage. He survived three Winters in the Arctic only because he also learned from the Inuits.
No lost explorers have ever survived unless they fall in with the natives and learn their culture. Humans survive neither by their instinctive abilities nor by their intelligence. We survive because, by the selective process of cultural evolution we have assembled packages of cultural adaptations including tools, practice, and techniques that cannot be devised in a few years by a group of intelligent, motivated and cooperative individuals.
In all of these old narrative of lost expeditions, the natives are always described as tall, robust and healthy looking by the explorers. The moral of this is, if your culture gives you the knowledge to know what you are doing, you will survive splendidly, if not you die.
In 1835 a lone woman was accidentally abandoned on one of the Channel Islands 70 miles off the coast of Los Angeles. She survived for 18 years there because she was brought up on the island and had perfect knowledge of the local culture. When she was finally found, she was in great health.
There is no innate mental machinery to help us survive in a strange and foreign environment. We just don’t have the cultural knowledge that allows the natives to not only survive but to thrive.
Our minds, our social and our cooperative nature help us, but without cumulative cultural knowledge we are doomed. No innate mental machinery helps lost survivors survive. It is only cultural adaptations that save us. And these cultural adaptations involve more than just finding food and shelter. They also involve how we think and what we like and dislike. Cultural adaptations including norm’s, institutions, and languages graduate merge without anyone finally understanding how or why they work.
This is one of the best books I’ve ever read on why humans are as they are. And there is a lot more to this book, my comments here are just the tip of the iceberg. The real knowledge of this book I leave to you to discover. Below is a link to the book on Kindle. I highly recommend it.
The Secret of our Success: How Culture is Driving Human Evolution, Domesticating our Species and Making Us Smarter, by Joseph Henrich, Princeton Press, 2016
This post is by Fred Hanselman