Nonzero and NonsenseGroup Selection, Nonzerosumness, and the Human Gaia Hypothesis A review of "Nonzero: The Logic of Human Destiny," by Robert Wright, Pantheon, 2000, $27.50, 435pp., ISBN: 0-679-44252-9 Robert Wright
by David Sloan Wilson
Holy Leviathan! Superorganisms, once thought to be as imaginary as dragons, may actually exist. First James Lovelock proposed the Gaia hypothesis, which portrays life on earth as a giant superorganism that regulates its own atmosphere. Now Robert Wright’s new book Nonzero advances a Gaia-like vision of human society evolving toward a planetary superorganism, complete with its own brain. Our final destiny is the culmination of an evolutionary process that has been building superorganisms at an ever-increasing scale, first for organic life and then for human cultural life. Like the dragons of old, the superorganism concept stretches back through the ages. From Aristotle (who imagined the classes of society as like the organs of an organism), to Hobbes (who called the societal organism a Leviathan), to Durkheim and Malinowski (who initiated the tradition of functionalism in the social sciences), nature and society have been portrayed as scaled-up versions of individual organisms. However, evolutionary biologists examined and rejected the concept so thoroughly in the 1960s that their verdict has been repeated like a mantra in textbooks and journal articles ever since: Individual organisms evolve by a process of between-individual selection. For a larger unit such as a society or an ecosystem to evolve into a superorganism, there must be a process of between-society or between-ecosystem selection, which is theoretically possible but so unlikely that it can be ignored. Since natural selection almost never occurs above the level of the individual, only individuals possess the properties associated with the word organism. Societies and ecosystems are what individuals do to each other and their physical environment. They are not organisms in their own right. I am one of the few evolutionary biologists who has challenged this conventional wisdom. I agree with the central logic—higher-level adaptations require a process of higher-level selection—but I think that selection plausibly occurs at multiple levels of the biological hierarchy. Societies and ecosystems can vary in a heritable fashion, just like individuals, and they can replace each other on the basis of their properties. Superorganisms cannot be assumed axiomatically, but neither should they be the object of ridicule that they became in the 1960s. For most of the 25 years that I have been fighting this battle, progress has been slow. Especially during the 70s and 80s, mentioning superorganisms to an evolutionary biologist was like farting at a cocktail party; the typical response was to suppress a smirk and change the subject. I was therefore amazed to see Lovelock vaulting over the entire debate as if it had never taken place, and even more amazed to see Wright following suit with his human version of the Gaia hypothesis. How could they make such extravagant claims, at the grandest possible scale, after the great multilevel selection debate of the 1960s? Don’t they know that the evolution of a planetary organism would require a process of between-planet selection? The Shock Jocks of Evolution Science is a vast archipelago of disciplines that only partially communicate with each other. I don’t know much about atmospheric science and Lovelock, an atmospheric scientist, evidently didn’t know much about evolution. But Wright’s case is different. His previous book, The Moral Animal, masterfully recounted the field of evolutionary psychology, which is firmly rooted in the individual selection tradition. When I say masterful I am praising Wright as a science journalist and not the field of evolutionary psychology, with which I have what might be called a love-hate relationship. But, love it or hate it, you have to admit that Wright got it right. How, then, did Wright leap from the selfish gene in The Moral Animal to the planetary superorganism in Nonzero? The mystery—and irony—deepens when one realizes that Wright is not the first person in recent times to propose the human Gaia hypothesis. He is preceded by Howard Bloom, whose book The Lucifer Principle and series of 21 articles in the electronic journal Telepolis, cover the same ground. Bloom is a more colorful character than Wright. While Wright was working for respectable news magazines, Bloom made a living as a publicist for rock stars. If Wright is the New Republic, Bloom is shock radio. Nevertheless, both men were infected by the evolution disease and raced ahead of the timid scientific herd to announce the existence of the human Gaia. The irony is that despite their shared grand vision, they could not disagree more on how the human Gaia evolves. Bloom thinks that evolutionary biologists made a massive wrong turn with their rejection of higher-level selection in the 1960s. Group selection happens bigtime and is the force that evolves superorganisms. In contrast, Wright doesn’t even list the term group selection in the index of Nonzero and his only mention in the text is the following verbal smirk (p. 53): “But according to Darwinian theory, social hierarchies didn’t evolve for ‘the good of the group’, so followers don’t cheerfully submit to the leader for the sake of the public interest.” Wright explains the evolution of the human Gaia by something he calls nonzerosumness, which I will shortly try to interpret. I know that Wright and Bloom had the potential to interact because all three of us belonged to a lively e-mail network for evolutionary psychologists. When Bloom joined the network he started talking about group selection and human superorganisms with all the delicacy of Howard Stern. Bloom wasn’t farting—he had unstoppable diarrhea. The entire network went into a tizzy about how to make him go away. Against the advice of my friends, who warned that my lifelong effort to make multilevel selection respectable again would be tainted by association, I entered into a dialogue with Bloom. In no time he was referring to me publicly as a member of “the group selection squad,” a small group of intellectual desperadoes led by himself. Even I felt like backing out at this point, since for me “group selection squad” conjures an image of men in tights crouching behind trees. Nevertheless, I swallowed hard and continued what turned out to be a fun and intellectually stimulating relationship. My foreword to the second edition of The Lucifer Principle describes my cautious endorsement of Bloom’s ideas. Bloom eventually left our e-mail group for greener pastures but he didn’t disappear. I found him in a few minutes by first typing “superorganism” into my search engine. The first entry led me to a ten-member “global brain group,” only one of whom (Gregory Stock) is cited in Nonzero. This site included a global brain bibliography (most not cited in Nonzero), including Bloom’s Lucifer Principle and a link to his Telepolis articles. The first paragraph of the first article begins: “It might come as a surprise to the prophets of the global brain to discover that the researchers and theoreticians who specialize in evolution would sneer at the fundamental assumptions underlying this vision. The reason for the evolutionary community’s contempt? A concept called individual selection.” Did Wright steal the human Gaia hypothesis from Bloom? I very much doubt it. My guess is that Wright ignored Bloom as a group selection crank and proceeded to develop the human Gaia hypothesis on his own. Perhaps for the same reason, Wright seems to have ignored most of the other “prophets of the global brain” that dot the internet, the popular literature and (more sparsely) the scientific literature. Superorganisms are not discussed lightly by evolutionary biologists. The concept of adaptation is so powerful that, like fire or atomic power, it can be as destructive when used inappropriately as it is insightful when used appropriately. The great multilevel selection debate ended in a consensus that the concept of adaptation should be limited to the properties of individual organisms. The rejection of higher-level adaptations was regarded as an event comparable to the rejection of Larmarkism, closing the door on one set of possibilities and enabling attention to be focused elsewhere. R.D. Alexander, past president of the Human Behavior and Evolution Society, has called the theory of individual selection the greatest intellectual event of the 20th century. Although I have eked out a living as a town heretic, many colleagues have told me that it would ruin their careers to seriously endorse a group selection hypothesis. If superorganisms are back to the degree claimed by Bloom, Wright, and other “prophets of the global brain,” it would be a scientific event comparable to the rejection of group selection in the 1960s. However, it is hard to separate the wheat from the chaff in today’s world where science has merged with the trade book industry. Bloom and Wright are not scientists by training but neither are they functioning as science journalists, because there is no coherent field of superorganisms upon which to report. Both have been praised by respected scientists but it would be absurd to mistake such gushing endorsements for serious scrutiny. For example, Steve Pinker’s review of Nonzero in the electronic journal Slate reads more like a love letter than a sober scientific evaluation. In a world where science journalists are trying to function as scientists and scientists are functioning as book promoters, what is the average reader to think? As someone who has been functioning as a scientist on the subject of superorganisms, I feel like an archeologist whose carefully excavated site has become occupied by a travelling circus. It is time for everyone involved to recognize the gravity of the subject and to themselves start functioning as scientists, regardless of their past training. The situation is this: Wright, Bloom and others have proposed a grand vision of human superorganisms but they differ vastly in the proposed evolutionary mechanism. Some (including Bloom) invoke the reviled theory of group selection while others (including Wright) invoke the constellation of theories that seemed to replace group selection and which Wright gathers under the term nonzerosumness. Now it is the job of scientists to determine which position (if either) is correct or if, perhaps, the positions can be restructured so that they no longer appear so opposed to each other. For those who want to turn their attention from the circus of trade books to the careful excavation of science, I can report that there is a core of support for the human Gaia hypothesis, although perhaps not as grandiose as Bloom and Wright would like. To discover how superorganisms evolve, Wright, Pinker, and many others must return to the central logic of the great multilevel selection debate of the 1960s with which everyone, including myself, agreed. The Way it Was George C. Williams is regarded as a hero by evolutionary biologists of the individualistic tradition. Specifically, he is the hero who severed the head of group selection and mounted it on a pole as an example of how not to think for future generations. As Williams tells the story (the last time I heard it was at the award ceremony for Sweden’s Crawfoord Prize, which Williams received in 1999 along with John Maynard Smith and Ernst Mayr), he was a young postdoctoral associate at the University of Chicago and attended a lecture by Alfred Emerson, a highly respected biologist who portrayed all of nature as like a big termite colony. Williams knew that the evolution of higher-level adaptation was not so simple. As he listened to Emerson he thought “if this is evolution, I want to do something else—like car insurance.” Williams left the lecture muttering “Something must be done.” That something was Adaptation and Natural Selection, first published in 1966 and still widely read. Williams was one of many evolutionists who reacted against the superorganismic perspective but he became the icon for its rejection. I wish I could report otherwise, but scientists need their heroes and heads on poles as much as any other human group. The reason that higher-level adaptations cannot easily evolve is because natural selection is based on relative fitness. Imagine a population that consists of solid citizens and shirkers. The solid citizens produce a public good that is available to everybody, including themselves. For purposes of the example, let’s say that the public good can be produced at no cost to the solid citizens. Not only do they share the bounty, but they lose nothing by creating it. Even so, the solid citizens will not be favored by natural selection in this example because the solid citizens and shirkers do not differ in their survival or reproduction. Natural selection requires differences in fitness so raising or lowering the fitness of everyone in the population has no effect. If, as seems likely, the public good is costly to produce, the solid citizens will go extinct, even if they share the benefits, because their private cost reduces their fitness relative to the shirkers. Behaviors that are “for the good of the group” are at best neutral (if the public good is cost-free) and at worst maladaptive (if there is any cost associated with producing the public good). I have called this “the fundamental problem of social life.” Things are looking grim for group-level adaptations but there is a ray of hope. Imagine not one but many populations that vary in their proportions of solid citizens and shirkers. Even if shirkers fare better than solid citizens within each population, populations with an excess of solid citizens fare better than populations with an excess of shirkers. In short, there is a process of natural selection at the group level that favors solid citizens, just as there is a process of natural selection at the individual level (within each group) favoring shirkers. Group-level adaptations will evolve whenever group-level selection is stronger than individual-level selection. In retrospect, what could be simpler? Darwin was the first person to see both the fundamental problem of social life and its possible solution. In the following famous passage from The Descent of Man he used group selection to explain the evolution of human morality: It must not be forgotten that although a high standard of morality gives but a slight or no advantage to each individual man and his children over the other men of the same tribe, yet that an increase in the number of well-endowed men and advancement in the standard of morality will certainly give an immense advantage to one tribe over another. There can be no doubt that a tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage and sympathy, were always ready to aid one another, and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection. At all times throughout the world tribes have supplanted other tribes; and as morality is one important element in their success, the standard of morality and the number of well-endowed men will thus everywhere tend to rise and increase. It is interesting that this passage is ambiguous about the cost of behaving morally within groups. The phrase “little or no advantage” implies that morality is like the no-cost public good of my example or might even provide a slight private benefit for the moral individual. However, the moral behaviors described in the middle of the passage are definitely costly. Regardless, Darwin felt that the driving force behind the evolution of morality was the process of more moral groups replacing less moral groups, not the process of more moral individuals replacing less moral individuals within groups. Darwin did not comment on the fact that morality is restricted to members of one’s own group in his example. Additional work is required to show how morality can evolve in which the welfare of members of other groups is taken into account. One of Williams’ great contributions was to repeat Darwin’s analysis of multilevel selection for those who had forgotten or never learned it in the first place. Remember that science is an archipelago of disciplines, and an ecologist in the 1950s (for example) was no more likely to be a Darwin scholar than an atmospheric scientist in the 1980s. The following passage from Adaptation and Natural Selection shows that Williams retained Darwin’s central logic and added a claim of his own. I have added numbers to which I will refer later. (1) It is universally conceded by those who have seriously concerned themselves with this problem that...group-related adaptations must be attributed to the natural selection of alternative groups of individuals and that (2) the natural selection of alternative alleles within populations will be opposed to this development. I am in entire agreement with the reasoning behind this conclusion. Only by a theory of between-group selection could we achieve a scientific explanation of group-related adaptations. (3) However, I would question one of the premises on which the reasoning is based. Chapters 5 to 8 will be primarily a defence of the thesis that group-related adaptations do not, in fact, exist. Williams’ claim (part 3) was based on his review of the theory and data that had accumulated since Darwin’s time, which made higher-level selection seem so weak that it could be ignored. This was the assessment that turned Williams into a hero and group selection into a head on a pole. Wright’s statement that “according to Darwinian theory, social hierarchies didn’t evolve for the good of the group” echoes part 3 of the Williams passage quoted above. Had Williams been correct about the insignificance of higher-level selection, his hero status would be well deserved. Think of it—all superorganismic conceptions of nature, vanquished in a single stroke! No need to painstakingly measure the strength of selection at the various levels to see what evolves! Individual self-interest becomes an all-encompassing explanation of life on earth! Williams himself must have sensed his momentous achievement because he ended his book with the following remarkable (for science) phrase: “I am convinced that it is the light and the way.” Two concepts are intimately entwined throughout the great multilevel selection debate: altruism and organism. An organism is a unit whose parts (called organs) coordinate to achieve collective survival and reproduction. Altruism is a behavior that benefits others at the expense of the altruist. It is easy see the challenge that altruism poses for group selection theory. Not only must there be a process of group selection, but it must be strong enough to counteract the strong selective disadvantage against altruists within groups. At least in retrospect, it is not so obvious why the concept of a group-level organism poses such a challenge for group selection theory. Of course, if coordination among the parts requires altruism, then the two problems become the same. But what if it is possible to achieve coordination without individual self-sacrifice, like the no-cost public good described earlier? Then part 2 of Williams’ statement would no longer apply and even weak group selection would evolve superorganisms because group selection is unopposed by individual selection. This reasoning is only plausible in retrospect. Williams did not say “group-related adaptations exist only when they are not individually costly”; he said “group-related adaptations do not, in fact, exist.” In this passage and elsewhere, Williams and most of the evolutionary community rejected all group-level adaptations in the same stroke. A good example is the hypothesis proposed by V.C. Wynne-Edwards, that populations evolve to regulate their numbers to avoid overexploiting their resources (a group-level adaptation) just as mother birds regulate their number of offspring so that there is enough food for all (an individual-level adaptation). Wynne-Edwards proposed a laundry list of mechanisms whereby population regulation could be achieved—low fecundity, territoriality, dominance, cannibalism. Some of these mechanisms are altruistic (low fecundity) but others are not (cannibalism). Nobody at the time said “Wynne-Edwards’ hypothesis makes sense as long as the mechanisms are not altruistic.” They rejected the hypothesis altogether with such zeal that Stephen Jay Gould recalled with disgust “the hooting dismissal of Wynne-Edwards and group selection in any form during the 1960s and most of the 1970s.” “Hooting dismissal” still describes the attitude of many (although by no means all) evolutionary biologists today and many more people from other walks of life who have learned about evolution from a hooting author. Consider the most popular college textbook on animal behavior, by John Alcock. Group selection is given an honored place at the beginning, as if to say “before I spend several hundred pages telling you how to think about animal behavior, here is how you should not think.” Alcock’s main argument against group selection is a Gary Larson cartoon showing the fabled lemmings running into the sea (presumably to regulate their population size), except for one lemming wearing a sly smile and an inner tube. For Alcock, this cartoon says all the tender mind of the student needs to know about what he calls “the group selection fallacy”: selection between groups is no match for selection within groups. Or consider the way that Helena Cronin describes the bad old days in The Ant and the Peacock, which made the New York Times bestseller list in 1991: “Many an ecologist, equipped with no more than a flimsy analogy, marched cheerfully from the familiar Darwinian territory of individual organisms into a world of populations and groups. Populations were treated as individuals that just happened to be a notch or two up in the hierarchy of life.” Notice that Cronin rejects the concept of superorganism, not just the concept of altruism. Perhaps I have said enough to convince readers that the edifice built by Williams and others, now almost 40 years old, has a crack or two. To show that the edifice has become a pile of rubble, I must refer to my book-length treatment on the subject with Elliott Sober (Unto Others: The Evolution and Psychology of Unselfish Behavior, Harvard University Press, 1998), which provides enough detail for readers to decide for themselves. Our conclusion is that group selection is a significant evolutionary force in nature and especially strong in the case of our own species. Bloom and Wright’s Superorganism Now we are in a position to evaluate the human Gaia hypothesis and the mechanisms proposed by Bloom and Wright. The two main questions are: 1) can human groups qualify as superorganisms, in the same sense that individuals are organisms? 2) If so, do human superorganisms evolve by a process of within-group or between-group selection? Bloom and Wright would answer “yes” to question 1, Bloom would answer “between-group selection” to question 2, and Wright, superficially at least, would answer “within-group selection” to question 2. To understand why Wright’s answer is superficial we must attempt to understand what he means by nonzerosumness. In some respects nonzerosumness refers to the potential for cooperation. Wright is saying that life includes more win-win propositions than we often appreciate. Instead of my gain being your loss, my gain can also be your gain. Both organic and human cultural superorganisms are fashioned out of win-win propositions, which generate more win-win propositions, resulting in a succession of ever larger units and culminating in the planetary human Gaia. So far, so good, but what does this mean in terms of the central logic of the group selection debate? Do the traits described as nonzerosumness increase the fitness of the individuals in a society, relative to other individuals in the same society? In that case, Wright would be challenging the central logic (part 1 of the Williams passage) by claiming that group-level adaptations can evolve without the help of group selection. Or, do these traits increase the fitness of everyone in the group, like the no-cost public goods I described earlier? In that case, Wright would be invoking group selection, which is efficacious because it is unopposed by individual selection. Both Wright and Bloom would be right on question 1 but Bloom would trump Wright on question 2. Unfortunately, it is hard to proceed further because Wright does not follow the central logic of the group selection debate. Both Darwin and Williams first compared the relative fitness of individuals within groups to evaluate individual selection (e.g., selfish individuals beat altruistic individuals within groups), and then compared the relative fitness of groups in the global population to evaluate group selection (e.g., altruistic groups beat selfish groups). Wright thinks it is enough to show that an individual increases its own absolute fitness by its behavior. He does not discriminate between a low-cost public good and a private good; both increase the absolute fitness of the individual, but they differ in the level of selection required for their evolution. Like so many other evolutionary biologists, Wright has dismissed group selection so completely that he has forgotten how Darwin and Williams evaluated group selection. Wright often seems to imply that his entire theory can be explained in terms of win-win propositions, but consider his description of the fall of the Roman Empire (p. 135): Many of Rome’s glaring defects—exploitation, authoritarianism, corrupt self-aggrandizement—flow from deeply human tendencies. Time and again they’ve transformed promising civilizations into decaying, oppressive monstrosities. Time and again, history seems to cry out: Bring on the demolition crew! The demolition crew is the replacement of Roman society by more competitive neighboring societies. This description is much closer to the concept of altruism, in which between-group selection is opposed by within-group selection (part 2 of the Williams passage). Day by day and in so many ways, selfishness beats altruism within societies and only the demolition crew of group selection can reverse the process (Wright does not address the critical question of how variation between societies arises in the first place). If this passage doesn’t correspond to what Darwin and Williams meant by group selection, what would? Despite his avoidance of the dreaded G word, Wright’s account of organic evolution and human history is permeated with between-group selection processes which often are opposed by counterselection within groups. As far as I can tell, Nonzero can be summarized by making a few alterations in Darwin’s original theory of group selection: It must not be forgotten that although nonzerosumness gives but a slight or no advantage to each individual man and his children over the other men of the same tribe, yet that an increase in nonzerosumness will certainly give an immense advantage to one tribe over another. There can be no doubt that a tribe including much nonzerosumness would be victorious over most other tribes; and this would be natural selection. At all times throughout the world tribes have supplanted other tribes; and as nonzerosumness is one important element in their success, the standard of nonzerosumness will thus everywhere tend to rise and increase. Wright is smart, creative, a clever writer, and even a nice guy—at least when he isn’t talking about Stephen Jay Gould. However, Nonzero reflects a failure of scholarship so deep that most people (including Wright) can’t see it. Williams and others of his time were reacting to a form of bloated groupism that deserved to be rejected. Human culture is always adaptive. All of nature is like a termite colony. All animal societies regulate their densities. All ecosystems evolve toward increased information (whatever that is!). These claims are hopelessly grandiose. Only one statement has a legitimate claim at this level of generality: Adaptations at a given level of the biological hierarchy require a corresponding process of natural selection. Darwin’s original insight (and Williams’ clarification) was a momentous achievement that does deserve to be repeated like a mantra in textbooks and journal articles. It is only the empirical claim that higher-level selection is invariably weak that needs to be revised. Rather than categorically rejecting higher-level selection, evolutionary biologists need to follow the logic of parts 1 and 2 of Williams’ statement and let the chips fall where they may. Tragically, most evolutionary biologists who think they are following in the footsteps of Darwin and Williams have forgotten the central logic and have created a form of individualism as bloated as the groupism of the 1950s. Even more tragic, while remaining individualistic in his own mind, Wright has actually returned to the groupism of the 1950s, in which for every society that fails there is sure to be a different and better society next door to replace it. If Williams had read Nonzero after leaving Emerson’s lecture, he probably would have become a car insurance salesman. Wright is like someone who faces directly away from an object, bends over, looks between his legs, and claims to see a new object. Forgive the clownish image, but so many of my colleagues in evolutionary biology have been walking around in the same position for so long that something must be done. It is time to stand up, turn around, stop talking and start doing serious science that employs the central logic of the multilevel selection debate, and let the chips fall where they may. Beyond Theories of Everything Nonzero is about more than superorganisms. It is also about the directionality of evolution and the concept of purpose. It even aspires to become an inspirational story in a quasi-religious sense (one of the endorsements on the back cover says “Religions are made of such stuff”). There is more to discuss, but it is enough for one essay to explore the foundation upon which the edifice is built. Call me dull, but I think that the limited questions asked and answered by serious science offers an intellectual feast more satisfying than all-you-can-eat theories of everything. Not only does multilevel selection theory give the superorganismic view of nature and human nature a new lease on life (although in a more limited form than earlier grandiose versions) but it has many practical applications. In Unto Others we describe a group-selected strain of chicken that could save the poultry industry millions of dollars. That’s right-the intellectual feast includes chicken! Gaia might not exist at the planetary level but in our laboratory we are using ecosystem-level selection to evolve miniature Gaias that do useful things, like degrade toxic industrial compounds. It’s fun to speculate about a planetary human Gaia but smaller human groups can really be studied scientifically with respect to levels of selection and the presence or absence of organismic properties. Those who dismiss group selection like to portray me as the only proponent, but in fact there is a growing community of multilevel selectionists who publish in the best journals and whose grants are funded by the most competitive programs. For those who would like to read about human group selection from someone other than myself, I suggest anthropologist Chris Boehm’s new book Hierarchy in the Forest (Harvard University Press), which is a more modest and closely reasoned version of Bloom’s and Wright’s thesis. Much has been happening under the noses of those who dismiss multilevel selection with such confidence. For the moment, I will leave the theory of everything to Wright, Bloom and others. As for the quasi-religious element of Nonzero, call me profane but please hold the baloney.
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