Survival of the Nicest?

In Higher Superstition, a book remarkable both for its influence on the intellectual community and for its obtuse ignorance of the actual state of science, the authors told us that

Science is, above all else, a reality-driven enterprise…. Reality is the overseer at one’s shoulder, ready to rap one’s knuckles or to spring the trap into which one has been led…by a too complacent reliance on mere surmise…. Reality is the unrelenting angel with whom scientists have agreed to wrestle.¹

Any reader who wants to test this charmingly naive view of science should immerse himself or herself in the literature of evolutionary biology. Indeed, the immersion does not have to be very deep before the currents and countercurrents of ideology can be felt tugging at one’s understanding. Unto Others, a collaboration between Elliott Sober, one of the founders of the modern philosophy of biology, and David Sloan Wilson, one of the most creative theoreticians in evolutionary studies, wades into this turbulent stream at precisely the point where so many other adventurers have been swept away: the problem of the origin of altruistic behavior. Can natural selection have made us genuinely cooperative and unselfish in pursuit of the greater good of the many, or is apparent altruism nothing but an artfully disguised version of every man for himself? Have Professors Sober and Wilson really collaborated in order to spread enlightenment, or are they engaged only in a bit of academic career building, each using the other as a tool of their separate ambitions?

Darwinism, born in ideological struggle, has never escaped from an intimate reciprocal relationship with world views exported from and imported into the science. No one challenges the claim that evolutionary theory has had a wide effect on social theory. It is a cliché of cultural history that the explanation of evolution by natural selection served as an ideological justification for laissez-faire competitive capitalism and the colonial domination of the lesser breeds without the law. Nor are these evidences only of the quaint naiveté of the nineteenth century. Social Darwinism has had a continuous and vigorous life until today. Only three years ago a leading publisher of psychological monographs produced a book by a professor of psychology at a first-rank Canadian university claiming that the evident moral and cognitive superiority of Europeans over Africans was a consequence of natural selection in a cold rather than tropical climate. All the Africans got out of their experience of the survival of the fittest were greater libidos and longer penises.² The slightest suggestion, however, that evolutionary biology has imported some of its conclusions from social theory and political prejudice will be greeted by incredulity and indignation on the part of scientists convinced of the intellectual autonomy of the study of nature. Even those who insist that they concentrate on the “internal” history of science agree that Darwin’s notion of the struggle for existence, and the consequent differential survival of those types with greater fitness for the struggle, owed a great deal to the economic and social theorists of the late eighteenth and early nineteenth centuries, such as Dugald Stewart and the Scottish economists; and they recognize that so-called “Social Darwinism” was a popular ideology long before the composition of the Origin of Species.

Yet the mere mention in the pages of The New York Review of Books of this now conventional understanding was enough to invoke an irate response from one of the leading physical scientists of our time, Max Perutz, who assured readers that Darwin would have reached his conclusions irrespective of the intellectual atmosphere of the mid-nineteenth century because, after all, those ideas were a revelation of natural reality. Scooping the authors of Higher Superstition by a dozen years, Perutz claimed that any suggestion of the importance of social context was evidence of the corrupting influence of Marxism on intellectual life.³

The pervasiveness of general world views in evolutionary biology, however, goes well beyond the relatively uncontroversial influence of nineteenth-century social attitudes on the historical origins of the science. They have informed at all times, including the present, the way in which evolutionary biologists describe the reality of nature. Hegel’s lament in The Lectures on the Philosophy of History that “instead of writing history we are always striving to find out how we ought to write history” is more applicable to evolutionists than to German historians.⁴ There is no simple and direct “truth” about how to understand the history of life on earth.

The descriptive facts of evolution are not at issue. Natural scientists agree that roughly three billion years ago life appeared from inanimate materials and that since then the organisms that have inhabited the earth have been connected to one another by a chain of ancestry that can be reconstructed from the fossil record and from molecular, physiological, morphological, and behavioral similarities among living organisms. When there are disagreements about facts they are a consequence of the necessary ambiguities of historical reconstructions from limited observations.

There are brief, bloody struggles over fine details of ancestry, such as, for example, whether human beings have a more recent common ancestry with chimpanzees or with gorillas, or whether one’s favorite fossil primate is in the direct line of human ancestry. There are, as well, disagreements about whether or not the appearance of new species is often the consequence of very short but dramatic periods of splitting and morphological change, separated by long periods of boring stasis (the theory of “punctuated equilibrium”) and whether the disappearance of old species is often the result of literally world-shaking events like a collision with a meteor. Some ideological predispositions may enter in these latter cases, pitting those who are committed to the view that history is a long and gradual incremental movement against those who see revolution as a vital element in historical change.

In the end, however, such disagreements do not create deep and long-lasting divisions among evolutionists. Sometimes, as in the case of the human-chimpanzee-gorilla puzzle, it is agreed that no observations can ever resolve the question, and, anyway, what difference does it really make? Sometimes, as for the arguments about punctuated change and catastrophic extinction, a pluralistic agreement is reached with only local skirmishes persisting about whether this or that particular sequence of fossils fits more closely the gradualist or catastrophist scenario. Individual careers are made by emphasizing one sort of case rather than the other, but evolutionary biology as a whole is not threatened with reformulation.

It is when we move from evolution as narrative to evolution as universal history, from Hegel’s category of Original History to his Reflective History, that the predispositions of ideology come to dominate the science. The practitioners of evolutionary biology, no less than their philosophical and literary hangers-on, seem determined to impose on the history of life a single unifying principle or viewpoint that is said to be what evolution is “really all about.” And not only evolution as a process, but every detail of the life activities of every species that has ever lived, certainly including Homo sapiens. There are three such unifying themes that plague evolutionary biology today, and all three converge in the problem of altruism that is the main subject of Unto Others.

The first claimed universal in evolution is that it is an optimizing process. External nature poses problems for organisms, problems of life maintenance and of reproduction. Different individual organisms “solve” these “problems” differently and those who solve them “best” leave more offspring who also inherit their method of solution through their genes. Organisms propose and nature disposes. As a consequence the best solution becomes more common and finally comes to characterize the species. Thus, natural selection, a process of conjecture and refutation, leads ineluctably to the optimum solution to the problem. The claim of optimization arises in part from an unreflective literal reading of a nineteenth-century slogan, “survival of the fittest,” but also from a widespread misunderstanding of a technical issue. Given a particular environment, each genetic type in a population has some probability of survival and reproduction, what we call the fitness of the type. These fitnesses can be averaged, weighting each by how frequent the genetic type is in the population, to produce a number called the mean fitness of the population. Evolution is a change in the frequencies of the different types from generation to generation, with the result that the mean fitness of the population changes from generation to generation. It turns out that if natural selection is the only force operating on the population, the frequencies change in such a way that the mean fitness of the population only increases and never decreases.

The standard metaphor is therefore evolution as a mountain climber. Mean fitness is like the altitude in a mountain range, and natural selection is like an inner compulsion of a climber to climb yet higher and higher. Hence evolution by natural selection is seen as a maximizing or optimizing process driving species to greater and greater fitness. But that conclusion is a misunderstanding of the metaphor. A mountain range, including the Fitness Mountains, contains many peaks of different heights, and a climber who wishes to ascend the highest peak must be able to see into the distance and choose an appropriate path to Everest. Unfortunately, the mechanism of natural selection does not allow such global behavior and forces the population upward along the particular local slope on which it finds itself. In this case the mountain climber cannot see beyond the end of his alpenstock and has no way of “knowing” that higher peaks exist elsewhere, that there are even better possible solutions than the present one.

The false view of natural selection as a process of global optimizing has been applied literally by engineers who, taken in by a mistaken metaphor, have attempted to find globally optimal solutions to design problems by writing computer programs that model evolution by natural selection. In fact, none of these schemes of “genetic algorithms” has yet succeeded in solving a design problem that was not already solved by more conventional methods. The most talked-about example is the famous “Traveling Salesman’s Problem,” which has implications for any design question that involves connecting a large number of points by straight pathways. This problem calls for a generalized Willy Loman to visit a large number of cities that are spread out over the map in an irregular way, taking the shortest (or cheapest) possible total path, without visiting any city twice. Vast amounts of computing are required to get even an approximate solution, and genetic algorithms are worse than other techniques.

Believers in evolution as an optimizing process assert more than that natural selection is a rule for finding the best. They claim, too, that all properties of all species are a consequence of direct natural selection for those characteristics. None is accidental, none is a failure of optimum adaptation, none is the epiphenomenal consequence of other, perhaps optimal, features, none is the ineluctable outcome of being flesh. The mountain climber never tumbles down a crevasse, dizzy from a deficiency of oxygen or an excess of brandy. It has been seriously proposed by a respectable evolutionary ecologist, for example, that the holes that rot in the trunks of older trees are really a favorable adaptation because small animals are attracted to live in them and these animals help to spread the seed of the tree. A more extreme form of this hypothesis is that even the fact of death is a consequence of natural selection, designed to prevent those of us who are reproductively worn out from eating the bread of our still-fertile offspring.

Evolutionists have not always been such Panglosses, however. The Whiggish belief in evolutionary progress by survival of the fittest that characterized the exuberant expanding capitalism of the last half of the nineteenth century gave way, after the unimaginably bloody slaughter of the First World War and the economic desperation of postwar depressions, to a rather less optimistic view of the march of history. With essentially the same facts of natural history at their disposal as are now available, the evolutionists of the first half of the present century differed from present-day evolutionists in their characterization of the process. Evolution: The Modern Synthesis, edited by Julian Huxley in 1942, which brought together the leading evolutionists of the time, was filled with the consciousness of historical contingency. While some argued that the differences between species were a direct consequence of natural selection, others argued that reasonably often “the race is not to the swift, nor the battle to the strong, nor riches to the wise man, but time and chance happeneth to all.” H.J. Muller, winner of a Nobel Prize for his demonstration of the artificial induction of mutations by ionizing radiation, thought that deleterious mutations would accumulate more and more over time in populations as a consequence of purely random variations in individual fecundity, with a consequent steady degeneration in the species.⁵

During the last thirty years, however, despite the fact that the technical literature of evolutionary genetics has emphasized more and more the random and historically contingent nature of genetic change over time, the literature of natural history, of ecology, and of behavioral evolution, and the growing body of popularizations produced by evolutionists, philosophers, and science writers has again become unrelentingly optimalist. This change has not occurred because a mass of new facts has forced us to a new vision of reality. On the contrary, the development of very sophisticated statistical methods has been required to detect any signal of natural selection above the din of random DNA variation that has been observed by modern molecular evolutionists. Where does the faith in optimality come from? Certainly not from inside science.

The second article of ideological orthodoxy, virtually unchallenged at present by any student of evolution, is that the individual organism is the object seen directly by natural selection. That is, any argument that some characteristic has been favored by natural selection must be of the form that individual members of a population who display the characteristic will leave more offspring than those who have other traits. What is being explicitly denied is that characteristics favorable to the population as a whole will evolve by natural selection, except as a secondary consequence of the greater fitness of individuals over others within the population. So, for example, we are not allowed to claim that linguistic communication between humans was favored by natural selection by arguing that a group of protohumans who could talk to each other would be at an advantage in warfare or hunting over other groups who were without language. Somehow it would have to be argued that a single individual with a greater lingusitic capacity than others would, as a consequence, leave more offspring.

Moreover, as a fortune I once received in a Chinese restaurant pointed out to me, “the best talkers don’t necessarily make the best listeners,” so we need two sorts of selection simultaneously, which only compounds the problem. If we were to allow, however, that a characteristic might spread through a species because local groups that accidentally possessed it somehow took over the species, the problem would be solved. This possibility of group selection has been regarded as anathema by nearly all evolutionary biologists, although entirely without empirical evidence. The obvious hypothesis is that the exclusive concentration on the individual as the unit of selection is a direct transferral onto evolutionary theory of the central role of the individual as actor in modern social and economic thought. If there is a benefit to the group, it is simply a manifestation of the invisible hand.

The difficulty posed by a combination of pan-selectionist optimizing theory with a commitment to the individual organism as the sole locus of natural selection becomes obvious when we consider altruism. The evolutionary theorist means by altruism a particularly strong form of benefit to others in which that benefit is at the expense of some harm to the altruist. Organisms do indeed seem to sacrifice themselves for others’ benefit. Mothers and fathers sacrifice food and rest for the benefit of their children, and siblings can usually count on each other for support in time of need. But altruism extends outside the family. Soldiers throw themselves on grenades to save their comrades, and even in New York a man may give up a taxi in favor of a pregnant woman.

The problem of altruism is regarded by some evolutionists, in particular those who identify themselves as sociobiologists, as the outstanding problem of evolutionary biology and its solution as the outstanding contribution of sociobiological thought. Hillel is said to have once been challenged by a prospective convert to provide the essence of his religion while standing on one leg, to which the sage replied, “Do not unto others what you would not have them do unto you. All else is commentary.” For sociobiologists, too, unselfishness is the key and all else is commentary. Their real program is not simply to explain social phenomena as a product of evolution, but to demonstrate the universality of optimizing natural selection as the explanation of all features of all organisms. The ambition of evolutionists to possess a universal rather than a contingent truth is in danger of being thwarted by the seeming irrationality of unselfishness. Ought natural selection not have expunged such counter-reproductive behavior? Doesn’t natural selection favor the selfish, those who maximize their own life and reproduction, at the expense of others? Where have we gone astray?

The answer offered by the most trendy evolutionary theory is that we have not gone down far enough in our search for reality. The group is not the unit of selection, nor even the individual organism. In the third article of ideological orthodoxy, it is the gene that is the real object and beneficiary of natural selection. Organisms are merely the temporary and mortal vehicles of the immortal DNA, instruments of the selfish genes. In Richard Dawkins’s disturbing metaphor, we are “lumbering robots” under the direction of the genes that “created us, body and mind.”⁶ If we take the gene’s-eye view, then what appears as altruism at the level of the individual can be understood really as a form of selfish manipulation by the devious genes. If it is the “purpose” of a gene to maximize its own reproduction, then this can be accomplished in different ways. One is the usual pathway of influencing the development and physiology of the individual organism, causing it to out-reproduce other organisms.

Another way, called kin selection, is to make me help the reproduction of other organisms that carry genes of the same kind, even at the expense of my own reproduction. Because my close relatives are likely to carry genes identical to mine, acquired from our common ancestor, then a gene can do just as well by increasing the welfare of several of my kin at my expense. For example, from the gene’s point of view, two of my brothers or sisters are worth one of me, because on the average they carry about half of the same genes as I do. So, if a sneaky gene can induce me to give up some resources to them without utterly bankrupting myself, its own purposes would be well served.

Yet a third way, producing altruism to unrelated strangers, is to lend fitness at interest. I will do a favor to you, and therefore to your genes, even at some cost to me, hoping that your genes will make you reciprocate at a future time, to the benefit of both batches of DNA. An example offered by sociobiologists is the saving of a drowning man, at some risk to the lifesaver, who hopes for future reciprocation. The trouble with this example is that the last person I would count on to save me from drowning is someone who could not swim well enough to save himself. Nor do the books quite balance in the case of the soldier who throws himself on a grenade, but nothing is perfect and the supposition is that on the average over all situations things will work out.

To make it work, however, we need some appropriate mechanism of biological mediation between genes and behavior. Can there be genes “for” being nicer to your brothers and sisters than to your second cousin once removed, or for casting your bread upon waters whose ebb is balanced by their flow? Can genes really modulate the structure of the central nervous system to produce just the right contingent behavior? Nothing is known by way of an answer to this question, and, more important, there is no program of empirical work on the central nervous system intended to make these formal speculations into concrete anatomy and physiology. At this point in the wrestling match the “unrelenting angel of reality” seems to have its wings pinned to the mat.

At first sight, Unto Others appears to be a reformulation of the now orthodox view of the evolution of altruism. It is, however, a great deal more subversive than that, for, if its alternative scheme is taken seriously, evolutionary biologists should stop characterizing the process as one in which genes drive organisms to develop particular characteristics that maximize their fitness. Genes cease to be the “real” beneficiaries of natural selection; individual organisms cease to be the sole “real” objects directly seen by the selective process; there is nothing that is optimized or maximized (except in a tautological bookkeeping sense), and the entire process of evolving a particular behavior does not require that there be genes “for” the behavior.

It might be supposed that some external ideological commitment might be invoked to explain Sober and Wilson’s radical revision of the theory of the evolution of altruism. Surely Kropotkin’s replacement of competition by cooperation in his own theory of evolution was the consequence of the self-conscious application of a principled general position. The case of Unto Others is more easily explained, however, as arising from institutional and idiosyncratic causes. Intellectual work is supposed to be a combination of originality and hard thinking. Unfortunately, there is some contradiction between these, at least in evolutionary theory. Careers are often made either from an ambitious but poorly thought out originality, or a skillful but mechanical analysis of a well-worn theme. Unto Others is precisely that combination of radical reexamination of a system of explanation, an examination from the roots, with a rigorous technical analysis of both biological and epistemological questions that we all are supposed to engage in. What marks off their intellectual production is not its ideology but the seriousness with which they have taken the intellectual project.

The hinge of Sober and Wilson’s argument is a rejection of the prejudice that natural selection must operate directly solely on individuals. They point out that groups of organisms may also be the units of differential reproduction and they provide examples from natural history that can only be understood if, in addition to the survivorship of individuals, the survivorship of entire collections of organisms is taken into account. In fact, the effect of selection within groups may be the opposite of the effect between groups, with the group effect dominating the entire evolutionary process.

The story of the rabbit in Australia is a clear example. Rabbits were introduced into Australia in the nineteenth century in order to allow colonial country squires to continue the English tradition of huntin’ and shootin’. Unfortunately the squires’ marksmanship could not keep up with the reproductive rate of the rabbits, who quickly became a serious pest and competitor with sheep. An attempt was made to control the rabbit population by introducing an infectious lethal disease, myxomatosis, which spread rapidly and, at first, decimated the rabbit population. But then the rabbits began to increase again. As was to be expected, rabbits resistant to the disease organism had appeared, presumably by random mutations, and genetic resistance spread through the species by natural selection. In addition, however, the disease organisms had also evolved to be less virulent so that even susceptible rabbits were less damaged by the newly evolved pathogens.

This seems odd, because more virulent strains grow more quickly and should eliminate less virulent strains when competing within rabbits. The trouble with being virulent, however, is that, having taken over a rabbit, the virus kills it. Myxomatosis is spread from rabbit to rabbit by a mosquito and mosquitoes do not bite dead rabbits. So, having taken over the subpopulation of viruses by natural selection within a rabbit, virulent viruses have guaranteed their own eventual elimination by failure of that subpopulation to be transferred to new hosts. Ethnic cleansing has been the pathway to national suicide and the more benign eventually survive globally.

In considering groups as units of selection, it is important not to take too impoverished a view of what constitutes a group. It need not be a spatially defined unit, as in the myxomatosis case, where all the virus particles contained physically within one rabbit form a selected group that then may contribute to new groups in new rabbits. Groups may be delimited by any shared property such as food preference, temporal pattern of activity, gender, social class, or e-mail list. Anything that sorts individual organisms will do, including kinship. Thus Sober and Wilson swallow up kin selection as a special case of their more general theory. For group selection to operate, all that is required is that there be collections of individuals that interact with each other in some way separate from the interactions of other individuals in other groups, and that subsequently the groups contribute differentially to the next generation.⁷

In fact, it is hard to imagine any real biological species that is not broken up into such “trait groups” according to many different traits, so that a mixture of individual-level selection within collections and group-level selection between them ought to be the rule. The exploitation of plants as a food resource for insects is an example. Female moths make a choice of plants on which to lay eggs, depending on various physical and chemical properties of the plants. There is variation in preference among females within a moth species, partly as a consequence of genetic differences between moths, but also as a result of exposure to different plant chemicals during their own development as caterpillars. All the caterpillars that hatch out on a given plant are a “trait group,” having in common the consumption of a particular plant with particular characteristics. During their lives as caterpillars some will be more efficient or voracious than others, and so survive better to adulthood. Their genetic type will therefore increase within a group.

But this fact alone is not sufficient to predict whether their type will increase in the species as a whole. That increase or decrease depends in part on the commonness or rarity of the plant variety on which they survived and on how choosy they will be as adults when they are ready to lay eggs. A type that survives extremely well in competition on a rare plant will decrease in the species as a whole if its members insist on laying eggs on that rare plant, but may increase if they are more catholic in their tastes for plants. The ultimate pattern of plant consumption for the moth species as a whole is, then, a consequence of a mixture of individual and group selection in which the balance depends in part on how widely the individuals born on one sort of plant will disperse to other sorts of plants to produce the next generation.

Using the trait group approach, Sober and Wilson show quite convincingly that species may evolve altruistic behavior provided that the frequency of altruistic types within groups has an effect on the contribution of the group as a whole to the next generation of the species. If some group has, by chance, a higher frequency of altruistic individuals, and if the consequence is a larger number of offspring for the group as a whole, then even though there is some selection against the altruists within each group, altruism may come to characterize the species. Demographic studies of Native American groups have confirmed that, as might be expected, so-called “war chiefs” who were elected to lead their fellows into battle had smaller numbers of children as a consequence of their greater likelihood of death in combat. Success in war presumably enhanced group survival, however, so the altruistic act of the war chief, sacrificing himself for the group, would nevertheless lead to a survival and spread of the altruistic institution.

The modern ideology of population control predisposes us to think that small families are good for the individual, good for the family, and good for the species as a whole. Large families are harder to support and demand a sharing out of limited domestic resources, and we all know that the world is being ruined by overpopulation. But such an argument confuses the present with the past, owners with peasants, and well-being with numbers. For most of the history of agricultural Europe, land-owning families were well advised to have the largest possible families in order to maximize, by marriage connections, the land and military force on which they could depend. Even today, in rural agricultural India, family prosperity is increased, not decreased, by extra children whose unpaid agricultural labor often means the difference between a net profit or loss to the family.⁸ Moreover, the question of the increase or decrease of numbers in a population should not be confused with their prosperity. The prosperous few have more than once succumbed to the ill-fed masses.

Obdurate genic selectionists will respond that, irrespective of the mechanical details, all that matters in the end is which genes increase and which decrease. Groups, like individuals, are here today and gone tomorrow. Only the gene remains, so we need to consider only the differential reproduction of different genes, however that may be mediated. By definition, a gene is more fit in evolution if it leaves more copies in the next generation. But this bookkeeping trick confuses causes and effects, or, rather, eliminates material causes by reifying statistical effects. First, it confuses random changes with selective changes. In all countries at all times surnames become more or less common, and even extinct, because of variation in reproductive rates among families that are purely at random with respect to the names themselves. Martin is the most common French surname, whereas Bonaparte is practically nonexistent. This is a consequence of the fact that when surnames were created Martin was a common given name, but also that Martins have left a lot of children and Bonapartes only a few.

We would not want to say, however, that these names in themselves had some causal efficacy in reproduction, whatever the social and biological properties of their carriers may have been. That is, we would not want to ascribe Darwinian fitness to a name. There are many causes for an increase in genes that have nothing to do with the direct physiological consequences of bearing those DNA sequences. Different families leave different numbers of offspring for reasons that are at random with respect to a particular gene, so in a finite population of organisms there will be random changes in the frequency of genes from generation to generation. These random changes eventually cause the complete loss of one form of a gene and its chance replacement by another form.

This process of “neutral evolution” characterizes most changes in DNA during evolution, and its very selective neutrality is the basis for the reconstruction of the past relationships of living species. Sometimes unselected genes are swept rapidly to a high frequency because they happen to be on the same chromosome as a gene that is itself the object of natural selection. To assign fitnesses to genes that increase or decrease by chance or because they hitchhike on the chromosomes of other genes is a tautology that completely obfuscates the actual causal events.

Second, there is a confusion of the level at which causal action is occurring. The effect, at one level, of processes occurring at a different level may give an incorrect picture of what is happening. A famous example was the suspicion during the 1970s that the graduate school at the University of California at Berkeley was discriminating against women, because the overall acceptance rate of male applicants was clearly higher than for females. When each department was looked at separately, however, men and women were being accepted at the same rate at which they applied. The apparent discrepancy arose because women were disproportionately applying to the departments with the lowest overall acceptance rates. That is, they were engaged in riskier behavior than men, so they failed more often when averaged over all groups, although not within any given group.⁹

A gene with no deleterious effect on its carrier, but which is present in a species that lives only in the rich soil on the sides of slumbering volcanoes, will not decrease in frequency within that species (and may even increase), but its overall prospects are dim. To claim that selection is operating against this gene just because the species within which it occurs lives in a risky environment is an example of what Sober and Wilson call the “Averaging Fallacy.” To call it a “fallacy,” however, misses the point. The issue is not an analytic one as the word “fallacy” implies, but a metaphysical one about causal reality. If one continues to insist that the gene is what “really” matters, or professes a complete lack of interest in material mediation in favor of computing outcomes, then there is no fallacy. Once again the angel of reality seems to have abandoned us.

A large part of Unto Others is taken up with a classic problem in philosophy and psychology that is analogous to the evolutionary question of whether the appearance of altruism at the individual level is really selfishness at the genic level. Is human altruism really egoism, or even pure hedonism, in disguise? Egoism is entirely self-directed. The egoist asks only “Is it good for me?” The answer, of course, may involve whether it is good for others, who may also be egoists, because it is beyond dispute that we may sometimes benefit ourselves by means of benefiting others. The egoist must spend a certain amount of time doing cost-benefit analyses, but with confidence that some bread is worth casting on some waters.

The important point of the claim for egoism is that the welfare of others enters the calculation only instrumentally. Hedonism, on the other hand, is a particular psychologistic and somewhat unreliable variety of egoism in which the actor asks only “Does it feel good?” without making a calculation. If what I was told about cod-liver oil when I was a child is true, then the senses are an unreliable guide to objective benefit, and assuredly villains smile and smile even outside of Denmark, so how we feel about situations may fool us. Still, risky as hedonism may be, our apparent altruism may be only doing what makes us feel warm inside. That is, we always act only to achieve gratification, but we have been brainwashed by our upbringing and social circumstances into being gratified through being nice. Others then reap the benefit of our ultimate selfishness. A refusal to be tempted by the devil may, after all, only be giving in to the ultimate ego satisfaction of achieving sainthood.

Sober and Wilson are too well versed in the history of this ancient problem to claim they can know the truth of the matter. They know they cannot rule out either egoism or hedonism as the “real” source of human altruism, and they recognize these theories as being ideological predispositions that are not capable of unambiguous empirical tests. They are clearly tempted by the psychological experiments that are most easily interpreted as showing the existence of real empathy for others’ circumstances. For example, a group of test subjects is told that a group of their fellow students needs help in going over their schoolwork. Some of these needy students are described in such a way as to make it easier for the subjects to empathize with them while others are described in a more alienating way. In addition half the subjects are offered a mood-enhancing experience (such as pleasant music) whether or not they helped a student, while the other half were not offered such a reward. In the absence of the reward more subjects helped those with whom they were empathic. The other subjects, despite the promise of an unconditional mood-enhancing experience, still went to the trouble of helping those with whom they felt more empathy. So the claim of the experimenters is that real empathy counts. But Sober and Wilson admit that this sort of experiment is rather unconvincing, and they can offer no suggestion for a better one. They confess that their temptation to believe in a real effect of empathy, in addition to any hedonistic motivation, arises out of their own a priori predisposition to believe in irreducible altruism.

In the end, Sober and Wilson are entirely forthright in saying that they have consciously adopted a pluralistic perspective. In their view evolution occurs at many levels of causation, from the gene to the population. There is natural selection of genes, of individuals, and of whole groups, and all of these are going on in the evolution of altruism. In psychology they accept the existence of egoistic, hedonistic, and irreducibly altruistic motivations for apparently altruistic behavior. To the extent that they support attempts to explain phenomena at lower levels of causation, at the genic rather than the organismal, or the organismal rather than the population level, they do so only for strategic reasons. They are methodological reductionists, because to ascribe actions at higher levels without an attempt to explain them at lower levels invites an indiscriminate obscurantist holism that is the enemy of understanding. I share their pluralism, but, of course, that may really be because it makes me feel good.