I've been reading this new book by Nichola Raihani at a very leisurely pace and finally finished it. Raihani's background is in evolutionary biology and psychology, which is somewhat broader than that of most similar authors. I found it informative with respect to the latest research in these areas, but was a little surprised to see how the disciplines have changed in recent years. For example, the term "symbiosis," which I grew up with, is obsolete, as is the name "E.O. Wilson." On the other hand, Raihani is a great fan of Charles Darwin, and I give her extra credit for that. One of the main things that I like about the book is that it provides an unvarnished account of how life evolves – so clearly that it becomes obvious how tenuous it is that we even exist.
The early chapters describe pre-human evolution, such as the introduction of mitochondria, a type of bacteria, into other living cells. Mitochondria were once independent organisms, and they became part of eukaryotes, initiating the evolution of multicellular organisms. This is the kind of happenstance that characterizes evolution and results in significant evolutionary changes. In this instance, mitochondria became the energy source that made higher forms of life possible. There is also much discussion of our distant ancestors and how they differed from other primates. It has been inferred that serial monogamy has been common throughout human history, based in part on the fact that human testicles are an intermediate size between those of gorillas and chimpanzees. Gorilla males have small testes because they have captive females and don't need much semen to reproduce, whereas chimpanzee males mate frequently with multiple females in order to reproduce and accordingly have large testes. Comparatively, human males must have mated with fewer females than chimpanzees but did not have captive females at their disposal in the manner of gorillas.
Until very recently it was thought that humans were born immature because of their head sizes, but it is now believed that metabolic stress on the mother is the actual cause: there is a limit to the size of a baby that can be sustained by the mother. Another interesting idea, which occurred to me earlier, is that the attachment theory of child-rearing is not supported by existing evidence. According to two studies, children who were raised by their mothers were no better adjusted than children who spent more time away from home, when examined later. This makes sense, because alloparenting was the norm throughout human history, and the current arrangement with nuclear families is an aberration.
The bulk of the book describes the role of cooperation in evolution and specifically in the case of humans. Cooperation has always been linked to species survival, but not necessarily in the same manner as in humans. Other primates do not engage in much cooperation, which makes humans more like meerkats or ants in some respects. Some fish resemble humans in the limited sense that their behavior is monitored by other fish, and they can develop reputations; in that case, the level of cognition is extremely low and does not imply true socialization. As in other books that I've read, there is discussion of how humans became cooperative on the basis of food shortages on the savannahs of Africa. Chimpanzees and gorillas did not live on savannahs, had plentiful food supplies, and therefore did not develop cooperative behavior. Hunter-gatherers were generally egalitarian as social units, and this changed when farming became the primary source of food. Farming led to increased populations in static locations and encouraged the development of social hierarchies, which permitted some individuals to engage in selfish behavior that increased their reproductive success.
For the present era, Raihani discusses how selfishness has made a comeback. She notes that selfishness has been the most dominant form in nature, and that cooperation exists only in small pockets. In the current environment, there are many incentives to cheat other individuals and to dismiss out-groups. To some extent, these preferences can be affected by socialization. For example, perhaps due to the influence of the Roman Catholic Church, northern Italians are more inclined to cooperate with wide groups to which they have little exposure than southern Italians, who tend to be more clannish and disregard higher authorities. This has been demonstrated in a study in which it is seen that people are more likely to return found wallets in the north than in the south. In the U.S., conservatives are typically unwilling to expend resources helping groups other than their own, thus their preference for low taxes. Raihani notes that cooperation does have costs, and that in many circumstances it is not irrational to engage in selfish behavior. Finally, in the current era, with climate change accelerating, she emphasizes how functioning states build cohesion in which a collectivist mindset permits the development of solutions to otherwise insurmountable problems.
I appreciate Raihani's straightforward description of our situation, in which she does not resort to using ridiculous phrases such as "the better angels." Human behavior has always been about survival, and trying to pretty it up isn't going to solve any problems. I think that she is somewhat better prepared to discuss these issues than others because of her knowledge of evolution and psychology. She also has some familiarity with economics. However, with the problems now facing mankind, it would also be helpful to have some knowledge of political systems and AI. Although we are living in challenging times, we have the tools available to survive if we choose to use them.