Is it nature or nurture? Author says 'yes'
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In his new book, "Blueprint: The Evolutionary Origins of a Good Society" (Little, Brown, Spark, 2019), Nicholas A. Christakis presents the case that evolution has provided human beings with genes that encode the blueprint for positive, social behavior.

Christakis, the Sterling Professor of Social and Natural Science at Yale and a part-time Vermont resident, has written a splendid book. The writing is crisp, well-organized, and vivid. The metaphors for complex scientific and sociological concepts are often brilliant. I will long remember the importance of social networks due to his pointing out that both graphite, soft enough for pencil "lead" and diamonds, amongst the hardest substances on earth, are both composed of the same simple carbon atoms. The difference in their properties is due to how they are organized, i.e. their "social network."

This book is not for the faint of heart nor for those looking for a quick beach read. The 520 pages include 80 pages of small-type, single spaced end notes documenting his sources and a 13-page index that ranges from the primitive Ache tribe of Paraguay and John Adams to sociologists Benjamin Zadlocki and Morris Zelditch.

Along the way, Christakis builds a detailed and compelling argument that evolution has fashioned human beings in a unique and positive way. The forces of natural selection have over eons favored individuals who demonstrate positive traits such as cooperation, self-identity, friendship, in-group bias, gentle hierarchy, and learning. He refers to this group of behaviors as the social suite, a set of characteristics that have resulted in humans forming social groups and cultures that optimize their well being, happiness, and ultimately survival.

Christakis is not a starry-eyed optimist. He specifically points out that every component of the social suite is made possible by the tension with its opposite. Altruism is possible because we are also capable of a level of ethnocentrism, hatred, and inter-group conflict that is exceedingly uncommon in animals. Pair-bonding, the "stable, mutually dependent sexual relationship of some duration," is common to all human cultures around the world despite the strong sexual urge for pleasure that results in promiscuous mating in many other animals.

So why are humans kind and helpful to others even though they are not kin? And why have humans around the world developed some form of marriage (not always monogamous) that is built around love or another emotional attachment? Christakis argues that it is because of our genes.

The role of genes (listed in the index just above Genghis Khan!) in heredity was not identified until early in the 20th century, and the structure and function of the material of the genetic code, DNA, was only discovered by Watson and Crick in the 1950s. Over the next fifty years, scientists determined that specific packets of DNA (the gene) coded for specific proteins that were fundamental to the structure and functioning of cells. It became an accepted part of the biological canon that genes determined our physical and biochemical characteristics and that evolution acts through natural selection to favor mutations, such as random changes in an individual's genes, that result in advantages to that individual.

Christakis pushes the concept of the function of the genes to another level by arguing that genes also determine our social characteristics. He has waded into the nature/nurture argument by making a solid and compelling argument that our genes have a much broader role to play in our world, influencing if not determining our behavior, our social organizations, and our environment. In detailed analyses of the behavioral components of the social suite, he finds counterparts for friendship, pair-bonding, altruism, and cooperation in other animals, such as the hierarchy and group solidarity of elephant herds and the cooperation and mutual support in whales. From this he argues that humans are actually much more alike than different from other animals, and that man is deeply embedded in the natural world.

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From that start, he builds a case that what does differentiate man from other animals is our capacity to develop culture, defined as "information capable of affecting individual's behavior that they acquire from other members of their species through teaching, imitation, and other forms of social transmission." In humans, it is this hard-wired inclination to produce culture and to fashion diverse cultures responsive to our changing environments that are the crucial attributes of our species that have enabled us to survive and thrive over millennia from the Arctic to Africa.

Christakis proceeds to argue that our genetic code and our cultures have evolved in parallel and interactively to provide us with the social suite of behaviors that result in the optimal blueprint for human survival and happiness. While we do have the capacity for hatred, aggression, and murderous war in the name of ethnocentrism and nationalism, the predominant behaviors that evolution has favored are cooperation, altruism, and social living where learning and teaching optimize the outcomes for future generations.

This is not an easy book. Like Christakis, I graduated from medical school and am familiar with the scientific method of hypothesis formation, testing, and ultimately proving and incorporating facts into the body of scientific knowledge or rejecting hypotheses as false. Nonetheless, I found sections of the book to be heavy-lifting and slow going.

The book is beautifully constructed with detailed explanations and proofs drawn from basic science and sociological research, but its virtues are also its challenges. The detailed descriptions of unintentional communities resulting from shipwrecks, of artificial communities from religious communes to the hippies of the Vermont woods in the 1960's, of Hadza foragers of Tanzania, and of the pair-bonding in chimps and bonobos are all fascinating and clearly explained, but the details occasionally proved to be overwhelming for this reader.

By the time I reached the final chapter I was flagging. But as Christakis addressed critics who would label behavioral genetics as reductionist, determinist, positivist, and down-right wrong, my interest was renewed. He convincingly makes the argument that we ignore the genetic influences on our behavior at our peril. As he points out, Stalin and Mao did so when they thought that their people lacked hard-wired, genetic behaviors and could be forced to comply with social policies that were counter to these interests. Millions died as a result of their actions.

Christakis makes the point that it's not nature or nurture, but both nature and nurture. The good news is that our genes nudge us in the direction of social positives. We are destined to form social groups that in the long run promote cooperation and stable relationships of marriage and friendship. We are destined to learn from our predecessors and teach our children, and the multiple forms of culture developed around the world ensure that these traits are promoted and passed on.

Despite the often disastrous state of affairs in today's world, Christakis sends forth a positive and optimistic view for our future, a message that we desperately need today. He concludes by writing that "The arc of our evolutionary history is long. But it bends toward goodness."

Michael F. Epstein is a retired physician who reads and writes in Brownsville and Cambridge, Mass. He can be reached at his web site BookMarks at where you will find more than 1000 ideas for what to read next.


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