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Darwin’s birthday is a good opportunity to reflect on the larger significance of evolutionary thinking in our common life. This is especially important as we head into a period of history in which competition and the “war of nature” appear poised to replace communal action and empathy for the plight of those our politics leaves behind. Our national discussions over immigration, race, and the rising distrust of the “other” by much of white America highlight this shift, but no less significant is a decades-long trend to replace the New Deal consensus on economic fairness, common infrastructure, and political equality with the individualist, anti-cooperative rhetoric of libertarian and conservative economists and politicians.
Darwin Day is an especially important time to contemplate this shift because so much of economic theory is rooted in claims about what is “natural” in social behavior, and thus in our economic relations. Darwin himself seems to have painted a vision of organic evolution which was competitive and individualistic, with little or no explanation for the cooperation that is rife in the biological world. In the famous closing of the Origins, for example, the evolutionary process is described in poetic but essentially hostile terms:
It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external con- ditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
There is certainly grandeur in this view of life, and I have always found this a deeply moving passage, as have many since it was written in 1859. But there are several possible lessons from this passage, some of which highlight the cooperative element in evolution, and some which lead to thinking of evolution as essentially anti-cooperative and individualistic.
Darwin highlights, in his image of the “entangled bank,” with a multitude of species, so different and yet dependent upon each other for subsistance. The main message of the first part of this famous passage is the one that has always drawn me: the idea that the complexity of diversity of life is produced by the action of a few simple principles interacting in the fullness of nature’s circumstances. The link to cooperation as an essential part of evolution is weak, coming only through the mention of “dependency.” The passage finishes more explicitly, claiming that it is the “struggle for life” that the beauty and complexity of life arises.
It is fundamentally this “competitive” aspect of Darwinian evolution that gave rise, almost immediately, to “social Darwinism” and theories of eugenics that were used by late Victorians and the elites of the Gilded Age and early 20th century to justify their grip on economic and political power, their immiseration of the poor in the course of achieving their own wealth, and the lack of social welfare provisions or protections in our politics until much later.
The image of evolution as inherently competitive, and not cooperative, persists in our popular and even some learned cultures, despite the fact that the last half-century has seen an explosion in our understanding of the centrality of cooperation to evolutionary theory, and a deepening of our understanding of how natural selection can create biological and social mechanisms that foster cooperation.
The main difficulty in explaining how “selfish” selection favors “altruistic” cooperation, in fact, is not anything in nature itself, which is rife with cooperative phenomena, but our pre-existing biases, and the tendency of those biases to cause us to oversimplify complex phenomena. We in the social and biological sciences learn about the “prisoner’s dilemma” and elementary game theory, for example, and are easily convinced that cooperation is hard to evolve, and thus that self-interested behavior is “rational” and “cooperation” requires one to be irrational.
But of course I would not be writing this, and you would not be reading it, if cooperative behavior did not pay off. The earliest phases in the evolution of life were unicellular, and remained so for most of the history of life on Earth. Every animal, plant, or fungus visible to the naked eye is the product of a major evolutionary shift, where multiple independent cells banded together, first into loose colonies (as bacteria do today in biofilms) and then, in certain lineages, into simple multicellular organisms (such as Volvox).
The exact mechanisms by which multicellularity evolved are difficult to demonstrate given the low preservation of such forms in the fossil record, but they must involve a suppression of competition between the cells which form constituent parts of the larger organism. This suppression is accomplished by many mechanisms. One of the most important is the zygotic bottleneck that most animals and plants go through, where a new organism arises from a single egg or cell, and thus the many cells of the new organism’s body are (largely) genetically identical (see the work of biologists Leo Buss and Richard Michod for more detailed descriptions of the importance of germ-line/somatic sequestration). A second mechanism is essentially punitive: the cells of most animals, including ourselves, are programmed for automatic cellular death if they attempt to leave their cooperative role and drive for their own reproduction. This anti-social escaping of the cooperative bonds is what we call “cancer.”
Moreover, the evolution of multicellularity is not a “frozen accident” of evolution, having occcured by chance and then locked in. If we look at cellular aggregation as the requirement for multicellularity, a conservative estimate is that it evolved independently at least 25 times. Stricter definitions of multicelluarity, involving cellular communication and connection mechanisms, still show at least ten separate origins within eukaryotic organisms (once in animals, three in fungi, and six in plants). Far from being an accident of evolutionary history, not to be repeated if we could “replay the tape,” multicelluarity and the mechanisms of self-control that go with it appear to be common solutions to problems of life in certain environments.
Everywhere we look in the natural world, we see cooperative behavior, and the success it creates within species and social groups. The lesson, for economics and political economy, should be clear: self-interest is not the only principle that underpins behavior in our social world. In fact, in the last several decades research on the detailed mechanisms by which pro-social, cooperative behavior evolves and is stabilized within human societies has exploded. It is not longer possible to know, and assemble into a list, all of the papers and studies on the subject (even if I thought you, dear reader, wanted a bibliography from me).
The mechanisms by which cooperation can evolve within social groups, by biological as well as cultural evolution, are many, and they go by technical names such as “indirect reciprocity,” but they boil down to some simple principles. Far from being anonymous, one-shot interactions of the kind that most simple economic theories assume (usually in the name of mathematical tractability), social life is a multi-player, repeated interaction where we gain and lose reputation based on our ability to observe how others behave, “keep score,” and when needed, mete out social sanctions against those who fail to act well. These mechanisms operate in families, friendship circles, work groups, cities and towns, and even among sets of nations.
We have been told, in recent days, that our society’s success depends upon putting ourselves “first” and not cooperating with a variety of other groups: that the US should not cooperate with its long-time allies worldwide, that conservatives should not compromise with liberals on a spectrum of issues from health care to immigration to education, that there is a “cold war” between urban and rural America. These conflicts are undoubtedly real, and we should not lightly dismiss their depth or severity.
But we should also remember that each issue has many possible means of solution, and many means by which we can achieve failure or bad outcomes. Many of the best solutions, I believe, will necessitate cooperation at least in part, and we can only achieve that by ensuring that the full set of social sanctions and mechanisms are brought to bear to ensure that cooperation can win out and give us the best solutions possible.
It seems appropriate to close by quoting a slightly later Darwin, in his 1871 book “The Descent of Man,” where he wrote:
There can be no doubt that the tribe including many members who are always ready to give aid to each other, and to sacrifice themselves for the common good, would be victorious over other tribes. And this would be natural selection.
Happy Darwin Day!