Survival of the Friendliest: Understanding Our Origins and Rediscovering Our Common Humanity. By Brian Hare and Vanessa Woods. Random House,304 pages (2020)
I read the Kindle edition, which seemed to be complete, and had links that made looking at the many references easy.
I used to teach a course in the general education curriculum at my institution called Animal and Human. We read and discussed the work of Jane Goodall (Through a Window, 1990) and Franz de Waal (Good Natured, 1996) among others, trying to understand the connections between ourselves and our closest relatives, the primates, including chimpanzees and bonobos.I found these readings compelling because of the questions they raise about the nature of our cognitive and emotional lives and how our peculiar combination of traits could be produced by Darwinian evolution.
This book provides a popular summary of much research on the same questions since the mid 1990s and brings in some studies, which while not so recent, contribute to understanding the recent results. I’m neither a primatologist nor an animal behaviorist nor a cognitive biologist, so much of this was new to me.
The first part of the book deals with the author’s view on how we humans became the highly intelligent beings that we are, living in large, technologically advanced societies. Put briefly, they believe that around 80,000 years ago, Homo sapiens began to undergo an evolutionary change they call “self domestication.” Slowly at first, but then rapidly after about 50,000 years ago, humans became more friendly, which enabled them to live together in larger groups, which in turn promoted technological and other cultural advances. This led in the end to modern humans supplanting all the other lineages of the Genus Homo, so now the only traces of these peoples are found in the DNA from occasional intercrossing (see my post on Ancient DNA).
The key behavioral change was the acquisition of the ability to be friendly to strangers. If we live in large groups, say, more than a few hundred individuals, we will not be able to become closely familiar with everyone. We will continually be encountering people we don’t know. Most animals that exhibit complex social behavior show a strong aversion to strangers. Chimpanzees, for instance, are very hostile to any chimpanzee they don’t recognize as a member of their group. When groups become large enough, they tend to split, as Jane Goodall describes in Through a Window. The group at Gombe she was studying broke up at one point. Shockingly, the males of one group began systematically hunting down and attacking members of the other group, until none remained. Likewise males were observed to attack stranger females and kill their infants.
Humans, say the authors, somehow were in a position where it became more advantageous in terms of reproductive fitness to welcome outsiders into the group and to coalesce into larger bands. Why this happened cannot be easily determined, but bonobos may provide a clue. Hare and Woods think that they, too, may have undergone self domestication. This explains why levels of aggression are much lower among bonobos than chimpanzees. The key, they think, was that resources in their habitat are much more stable and productive than in habitats occupied by chimpanzees. This led to less competition and more cohesion among females, who could then control the aggressive tendencies of males. Females no longer gave clear signs of when they were on oestrus, making it harder for males to be sure who was fertile. This further reduced the benefit of dominating both females and other males. More freedom to move among groups, greater sharing of resources and other advantages followed.
Hare and Woods think dogs also self domesticated in the presence of large hunter gatherer bands in the late paleolithic. By being friendlier and less fearful or aggressive towards humans, they were able to exploit the waste dumps that were a feature of camps. Closer relations gradually developed, and at some point, humans began to do some selecting of dogs they found useful.
Friendliness alone was not the only change: it turns out that the physiological underpinnings of friendliness are in the brain and especially the modifying effects of oxytocin, serotonin and testosterone. These are developmentally regulated by genes that are expressed in the neural crest in very early embryos. These cells differentiate and migrate to different parts of the developing individual and affect not only behavior, but also skull shape, snout length, coat and eye color, the curl of the tail and so on. The authors claim that this selection on friendliness they posit brought along all the changes we see in dogs versus their wolf ancestors. Similar changes are seen in bonobos and humans as well.
To support this thesis, they recount the work of Russian geneticists and breeders, who in a few generations, produced domesticated foxes, with many of the traits of domestic dogs, by selecting for friendliness alone. It seems almost unbelievable that merely choosing the foxes most willing to approach humans, would have so many distinct effects. Since, however, the number allowed to breed each generation is a tiny fraction of the whole population, the selection factor is extremely powerful. Furthermore, as noted above, the genes that affect willingness to approach strangers also have impacts on many parts of the organism.
The second part of the book turns to the dark side: being friendly to members of your group means being unfriendly to members of other groups. Oxytocin makes mother bears feel good when they see their cubs, but according to the authors, it makes them that much madder when they perceive a threat
Dogs bark at strangers; humans are suspicious of anyone who doesn’t appear to “belong.” It is easy to create situations where something can be used to identify someone as from a particular category that is seen as a threat. Skin color, language, dress, religious signs and symbols are only too familiar examples. Demagogues use this all the time to divide groups and unite them against one another. If you can get your followers afraid enough and angry enough at some group of “enemies,” they won’t notice what you are doing to them.
So how do we guard against such proclivities becoming fatal to our peace and tranquillity? Hare and Woods think that most efforts to eliminate existing fears and prejudices are as likely to backfire as to work. In other words, you can’t talk people out of these perceptions, and efforts to stigmatize them may only create distrust and resentment. As a possible way to approach the problem, they cite the example of the people from diverse backgrounds who helped Jews during the Nazi occupation: the single factor uniting them was some experience of a close, friendly relationship with a Jew at some time during their early life. Apparently this immunized them against the vilification served up by Hitler and his followers. Can we find ways to achieve the same sort of immunization in our contemporary global society?
I think it would be difficult, given how valuable dividing people into categories is to politicians and marketers. It’s also hard to remedy historic wrongs without identifying the groups that have suffered them. Whatever self domestication achieved in the human species, it didn’t eradicate our impulse towards dominance and hierarchy entirely. We still have a need to feel superior to someone, even if it’s only Yankees fans. In a society where exploiting political, social and economic loyalties leads to wealth and power, it is very hard to get those with the most of both to kick the habit. Those less fortunate console themselves by feeling superior to those they fear and despise. As the old joke says: If you want a friend in Washington, get a dog.