The main idea of this book is based on recent research and experimentation that demonstrates more and more clear that humans became the most successful species due to development of tools for communication and cooperation allowing them to act with incomparable level of coordination and therefore putting them in the Ligue of their own. This process did not occur at once, but was rather a long evolutionary process in which two close connected processes occurred: biological evolution of human body and cultural evolution of human groups. All this could be understood only if looked at together, when, for example, development of language was accompanied by changes in the body that made it capable to produce more and more complicated sounds and gestures, in turn creating evolutionary advantageous abilities for superior coordination between individuals in the human group.
Actually author provides a list of most important insights drown from this book:
Here author describes his journey from engineering to anthropology that included forays into psychology, economics and evolution, initially genetic and then cultural, so he refers to names relevant to my own interests: Kahneman and Tversky, Ostrom, Boyd and Richerson, Haidt, and Romer. It is also important that author has hand on experience with ethnographic field research.
- A Puzzling Primate
At the beginning of this chapter author makes a very refreshing statement that humans are not really that smart as they believe they are and that success of human species could not be explained by individual characteristics such as brain size. It is much better explained by the fact that humans are cultural species and as such capable accumulate and use huge amounts of knowledge divided between individuals. This knowledge actually distributed into multitude of different individual skills that are used cooperatively, expanded and rectified across generations, and saved in various material forms so they could be restored as needed even if they are not in anybody’s head anymore. Author also provides a nice layout of the book.
- It’s Not Our Intelligence
This chapter is unusual in its main idea that humans are not really that much smarter than other primates, except for one specific area – social learning. Here is graph of testing results demonstrating just this:
- Lost European Explorers
This chapter presents samples of another poorly understood reality confirmed by multiple natural experiments when people of one culture found themselves in the new environment and were not able to survive without specific local knowledge and skills developed by other cultures, native for the given environment. Author reviews a number of such experiments that occurred with European explorers.
4 How to Make a Cultural Species
In this chapter author classifies domains of knowledge and skills necessary for survival:
After that he linkes this with various features of culture that facilitate cultural learning such as: Skill and Success, Prestige, Self-similarity that lead to aiming for acquiring a specific role in division of labor by sex and other parameters. Author also discusses cultural knowledge accumulation and role of older individuals in transferring successful survival mores from generation to generation. Finally author also discusses methodology of such transfer: conformity and mentalizing.
5 What Are Big Brains For? Or, How Culture Stole Our Cuts
This is about cultural/genetic evolution and author makes a point that in humans, unlike majority of other species, culture is driving genetics and he provide a table of how exactly it happens with reference to chapters of the book relevant to each feature:
After that author concentrates on relationship between big brain and its function as kind of outsourcing tool when humans outsource expensive big digestive tract to fire and cooking, inherent body weapons and armor to tools such as spear and shields, and so on. It is also interesting that in process humans become optimized for long distance endurance running. Author demonstrates it by discussing muscle composition and other features of human body including incomparable thermoregulation that allows rather save hunting by driving animals into exhaustion. The big brain is also very useful for obtaining and using vast amounts of information about animals and environment via cultural transfer.
6 Why Some People Have Blue Eyes
This chapter is about relatively recent human genetic mutations and how they were distributed among various people. Most important, it is about culture/genetic interactions that author summarizes in such way:
7 On the Origin of Faith
Here author moves to an interesting view of faith, including faith and taboos of “primitive” tribes, is information transfer method, which is highly effective and does not require clear understanding of causes and consequences, but assure compliance with the wisdom acquired over very long periods of experience. It is also very positively referring to traditions, which served humanity very well until now when we get into era of fast changes and effective accumulation of information outside of human heads. The chapter ends with interesting proposition that cultural adaptation is as powerful tool as genetic evolution, but works a lot more efficient and fast, resulting in contemporary world in which the humans – animals that developed technology of language and overall culture become absolutely dominant.
8 Prestige, Dominance, and Menopause
Here author moves to internal details of how culture works, discussing two methods of influence: prestige and dominance and providing comparative analysis for them:
9 In-Laws. Incest Taboos, and Rituals
This is about kinship relationship in hunter-gatherer communities that includes not only blood relatives, but also complex “in-laws” relationships and their cultural meaning. The main point here is that there is a multitude of variations with one common feature – one way or another they culturally condition individual to act cooperatively to assure group survival and obtain kind of group insurance for individual survival.
10 Intergroup Competition Shapes Cultural Evolution
Here author moves to the next obvious step – intergroup competition. The first question is how old this competition and simple answer is that it is well documented even in chimpanzees. The second – group expansion at the expense of others is mainly documented with farmers and herders at the expense of foragers, but it is because not that many foragers left and they are practically confined to small areas. However, there is plenty of archeological evidence that human groups expansion occurred on the huge scale initially at the expense of other species – a good example are Neanderthals, and then at the expense of other groups that were less competitive military, which is more than well documented.
This is discussion of rules setting and enforcing, something that author characterizes as specifics of our species:
There are quite a few interesting experiments that author presents in this regard, with some demonstrating automatic character of rule compliance, which actually decreases if people have time to think about it:
After this discussion author looks at the reasons for such automatic cooperation and concludes that it is a necessary tool for survival when individual survival and genes transfer to the next generation depends on one’s group survival and transfer of genes condicted by kin is good enough for evolution to support these features.
12 Our Collective Brains
By “collective brains” here author means totality of knowledge and skills of a group of humans distributed between their brains and/or recorded in some material form so that humans can extract information from these records. He demonstrates importance of this by retelling story of Intuit tribe that lost large number of elders due to disease and as result lost a significant part of their survivability knowledge. Eventually they were able to restore this knowledge only years later after contact with another tribe. Author also discusses similar case in Tasmania and laboratory experiments that demonstrated necessity of access to diversity of knowledge. Here is a graph demonstrating just that:
There is also somewhat interesting reference to Neatherthals who had bigger individual brains, but went extinct probably due to failure outcompete damber, but better organized humans.
13 Communicative Tools with Rules
This chapter is about human communication tools, most important of which is language. Author looks at quite a few important parts of this communication tool and provides a brief summary:
He also discusses how language and its development were impacting genetic evolution of humans.
14 Enculturated Brains and Honorable Hormones
This part is especially interesting because author discusses intermediate point between genetic and cultural evolution of humans such as genetically predefined learning process, which allows to learn one’s native language without accent in specific period of live, but then shuts it down. Author discusses livelong available ability to change one’s body and brain – famous example of London taxi drivers. Another interesting research referred here is on Chinese Americans and influence of unhealthy habits specific to this culture. Here is graph demonstrating this:
15 When We Crossed the Rubicon
Very nicely summarized his understanding of the history of cultural evolution in the table:
16 Why Us?
Here author discusses very important notion of bridge between animal and humans that we crossed. It is basically intertwining of cultural and biological evolution based on massive communications and cooperation between individuals that exceeds by far anything else that exist in any other group of animals. Here is the diagram demonstrating this bridge:
After that author discusses in details many of the boxes in diagram.
17 A New Kind of Animal
In the last chapter author discusses key changes in attitude to understanding humans and their development from direct linear and progressive path from genes via biology and psychology to culture and behavior to complex process with multiple feedback loops, when changes in culture lead to changes in biology and vice versa. Author also discusses uniqueness of humans and their comparison with other animals.
MY TAKE ON IT:
This is the most complete and well-supported look at the humanity and its roots that I encountered so far. The idea of interconnected genetic and cultural evolutions with multiple feedbacks is in my opinion the most realistic understanding of humans and their movement from an animal similar to any other to completely different creature that not only was able to expand and occupy all conceivable ecological niches, often pushing out or outright annihilating previously dominant species, but also achieved self-consciousness to such extent as mainly to control lots of genetic needs and features that no other known creature can do. Also interesting is that eventually we get to the point when human individual become able to control their own reproduction, produce practically infinite amount of food and other supplies on demand, use technology to significantly improve health, and, most important, turned everything upside down by turning meaning of individual live from successful reproduction, driven by blind evolutionary process into the consciously identified meaning of live being successful pursuit of happiness, whatever it means for any given individual.