In 1859, Charles Darwin published On the Origin of Species, a text followed by several other foundational works on the theory of evolution. In it, he describes the mechanism and successive stages that allow the most elementary life forms to evolve into other, more complex forms, especially into acquiring the mental states and emotions that characterize humans and numerous animal species.
Darwin recognizes in humans “instincts of sympathy and goodwill to his fellows, which is still present and ever in some degree active in his mind.”1 He conceives of sympathy as “a basic element of social instincts” and concludes that “the man who did not possess similar feelings would be a monster.” Contrary to a widespread misconception that Darwinism leaves no place for altruism, evolutionist theory insists on cooperation between individuals and on the development of empathy.
At a time when almost nothing was known about genetics, Darwin’s detailed observations and perspicacity revolutionized our understanding of the relationships between animal species and their history. Darwin understood that the diversity of species was the result of a long and continuous process of adaptation to surrounding conditions. Showing remarkable discernment in the study of the nature of relationships and particularities that had escaped his predecessors, Darwin collected his discoveries into a theory of evolution of species, based on the combination of three essential elements:
• genetic mutations, which occur at random and cause hereditary variations that lead to differentiation in members of a species;
• variations that allow individuals to survive better and thus reproduce are favored by natural selection, so that the individual bearers of these mutations become increasingly numerous over the course of generations;
• adaptation: If external conditions change, individual bearers of other features might be better adapted to the new conditions; under the selective pressure exercised by the surrounding environment, they in turn prosper over the course of generations.
The notion of genes emerged from discoveries made by Gregor Mendel (1822–1884), a contemporary of Darwin (1809–1882), but not until after Darwin’s death, and the structure of DNA wasn’t elucidated by Watson and Crick until the 1950s, which made Darwin’s discernment all the more remarkable. Today, we speak of genes rather than “hereditary traits,” but the foundations of the theory of evolution remain unchanged.
The birth of life corresponds to the appearance of entities capable of maintaining their integrity in a given environment, of reproducing and transmitting to the next generation the information necessary to the formation of new individuals. This information is coded in an ensemble of molecules that comprise the genes. Entities that have similar genomes and characteristics, and that, in the case of sexual reproduction, reproduce among themselves, form a species. They enjoy a certain degree of autonomy while still constantly being in dynamic interaction with their environment.
How does the transition from the most elementary forms of interactions to the most complex forms of psychological mechanisms occur? The various biological processes and behavior, first of all, have specific functions. For instance, the function of photosynthesis is to allow plants to use the energy of light; the function of incubation, that of keeping eggs warm until they hatch; that of hunting, as practiced by wild animals, of procuring food.
To this notion of function is added that of need. In order to grow, a tree needs water, oxygen, light, and nutritive elements drawn from the soil. These growth processes have become increasingly complex over the course of evolution. The needs of a bacterium, an oyster, a mouse, or a human being are all different, but within the biosphere all these species are interdependent on one another.
In the animal kingdom, these needs give birth to tendencies, which can go from the simple tropism of a bacterium which moves along a gradient of concentrated nutritive factors, onward to the propensity of an earthworm to move away from a dry, hot surface that endangers its survival, all the way to the complex tendencies and impulses among more evolved organisms.
The dimension of desire or aspiration is added to needs and tendencies when an organism acquires the ability to become aware of itself in a subjective way. Aspirations direct and facilitate the accomplishment of the organism’s functions, needs, and tendencies. The most elementary conscious aspiration of a sentient being is one that consists of avoiding suffering and searching for well-being. Aspirations become more and more complex as the appreciation for suffering and well-being moves from the physical realm to the mental realm.
When a predator kills its prey, the vital function of the prey is interrupted, and it acquires the function of food for the predator. The needs and aspirations of the prey are thwarted, but those of the predator are satisfied. The desirable or undesirable nature of a situation is thus a relative notion, depending on individual points of view.
The ability of an organism to become aware of its identity and its aspirations goes hand in hand with a corresponding ability to become aware that the other also has its own identity and aspirations. From this, empathy is born.
The aspirations of self and other agree or disagree; it’s at this stage that ethics enters the scene. Ethics is based on an appreciation of the desirable or undesirable nature of behavior (beneficial or harmful), or of a situation (fair or unfair), an appreciation that takes into account the other’s aspirations without neglecting our own. This evaluation is associated with a value judgment depending on the altruistic or selfish nature of our motivations.
An individual who takes no account whatsoever of others’ needs or aspirations uses others as tools in order to satisfy his or her own needs, without questioning the validity of his or her motivation and actions.
Altruism based on reciprocity leads to the “social contract,” that is, to a collection of rules regulating relationships between individuals, rules that people agree to follow because they themselves draw advantage from them.
Through empathy and reasoning, which culminate in the human, individuals are now able to put themselves in the other’s place, to consider the other’s point of view, to become aware of the other’s aspirations, and to understand that they are just as legitimate as their own. They then respect the other and stop considering the other as an instrument in the service of their own personal interests, and ethics takes on an additional dimension.
When this realization of the value of the other gives rise to a motivation and behavior whose final goal is to accomplish the other’s wellbeing, we speak of altruism and of compassion when the goal is to relieve the other’s suffering. An altruistic action may happen to benefit us personally without that being the ultimate goal of our action. It can also cost us, when we willingly decide to renounce some of our advantages for the sake of the other.
The quality and validity of an ethic increases with its degree of universality. Criminals, for example, can spend their time robbing people while still respecting a “criminal code of honor” that leads them to share their loot fairly. A malefactor or a tyrant can observe familial ethics, and be concerned for the well-being of his children, while he mercilessly oppresses the rest of the population.
We should note that most of our ethical systems take into consideration only human beings. That does not call into question the usefulness of these systems, but it considerably limits their extent. An ethic can be universal only if it takes into account the aspirations of all living beings, in all their modalities, and with all their degrees of complexity. According to such an ethic, the desire not to suffer that all sentient beings feel should be respected, even if it is not felt by a being endowed with a superior intelligence, and even if it is not expressed in a language that we humans are able to decipher. Those who enjoy a superior intelligence should, by that very fact, use this ability to recognize and respect among other beings the same desire to avoid suffering.
Ethics is fundamentally linked to altruism. It begins with altruism limited to those close to us and to those who wish us well, and then extends to strangers who belong to the same human family as we do, and it culminates in an interest in the fate of all sentient beings.
Are we able to practice such an ethic? We are biologically programmed for limited altruism, toward our kind and toward those who treat us well, but this ability can serve as a foundation for cultivating extended altruism.
Darwin envisaged three types of behavior: purely automatic and instinctive behavior (that of the simplest organisms); behavior of pursuing individual interests (often to the detriment of other individuals); and behavior stemming from social instincts that are notably expressed by parental care and sympathy for other members of a group. Darwin clearly envisaged the possibility among humans of extending this sympathy beyond the family circle, the clan, and even the human species:
As man advances in civilization, and small tribes are united into larger communities, the simplest reason would tell each individual that he ought to extend his social instincts and sympathies to all members of the same nation, though personally unknown to him. This point being once reached, there is only an artificial barrier to prevent his sympathies extending to the men of all nations and races. [If they appear different from him]… experience unfortunately shews us how long it is before we look at them as our fellow creatures. Sympathy beyond the confines of man, that is humanity to the lower animals, seems to be one of the latest moral acquisitions.… This virtue, one of the noblest with which man is endowed, seems to arise incidentally from our sympathies becoming more tender and more widely diffused, until they extend to all sentient beings. As soon as this virtue is honoured and practised by some few men, it spreads through instruction and example to the young, and eventually becomes incorporated in public opinion.2
In 1880, the Russian biologist Karl Fedorovich Kessler, then at St. Petersburg University, stressed the fact that, compared to the law of reciprocal struggle, the law of reciprocal aid is much more important for success in the struggle for life and for the progressive evolution of species. This idea inspired Peter Kropotkin to devote himself to the study of mutual aid among animals, the outstanding points of which he outlined in his Mutual Aid: A Factor of Evolution.
As for the phrase “struggle for life,” Darwin himself used it in a metaphorical sense. In fact, two dogs can fight over a piece of meat and two plants can “fight” against drought to survive in a desert. The two dogs are fighting against one another, whereas the two plants are both struggling against drought.3 In the latter case, the “struggle for life” does not imply any hostility between species. Some species emerge victorious from the evolutionary process without having to engage in the slightest battle; they have, for instance, a better immune system, or are equipped with eyes or ears, which allow them better to detect predators.4 Moreover, although organisms are sometimes in direct competition with members of other species or their own species in appropriating rare and precious resources, or else in establishing their rank in a social hierarchy, if we consider the totality of interactions over time, we note that in the majority of cases, this competition is neither violent nor direct.5, 6
Competition is generally more visible and more spectacular than cooperation. A brawl in a public place immediately draws a crowd of people, and attracts much more attention than a group of people who have been cooperating in various ways for hours. However, it is fair to state that human life is more reliant on cooperation than on competition. In fact, as Martin Nowak, Director of the Program for Evolutionary Dynamics at Harvard, explains, evolution needs cooperation in order to be able to construct new levels of organization: genes collaborate in chromosomes, chromosomes collaborate in cells, cells collaborate in organisms and more complex structures, these structures collaborate in bodies, and these bodies collaborate in societies.7 One thus finds cooperation among units sharing the same genes as well as among units carrying different genes. Throughout the history of life, units that were at first independent got together in a cooperative way and, over time, ended up constituting entire individuals, a human being for instance, or “superorganisms,” as in the case of a colony of ants. Thought of in this context, the word “cooperation” does not imply any conscious motivation, since it can be applied just as well to genes as to bacteria or to superior animals.8
In general, animals co-exist in various, more or less complex ways. Some remain solitary aside from brief periods of procreation. Gregarious animals, on the other hand, are drawn by the company of their fellows, and tend to share in common grounds, without necessarily interacting. On the scale of complexity, we then move on to the subsocial stage, characterized by the occurrence of parental care. At this stage, animals become considerably involved in raising their young until they are grown. In certain species, the next stage is the colonial stage, occurring in large colonies of birds, for example, in which although the parents take direct care only of their own offspring, they also oversee a common terrain that ensures the group’s security. At the communal stage, the females cooperate in taking care of the young, feeding them and protecting them. Finally, at the stage called eusocial, the most complex stage, one can observe the construction and defense of a communal habitat—an ants’ nest, for instance—in which the adults cooperate over the long term in raising the young, as well as in a division of labor and a specialization in tasks.9
Explaining altruistic cooperation has been one of the great challenges posed to the theory of evolution. This type of cooperation implies a cost for the individual, and so it is hard to explain from the point of view of “survival of the fittest,” a term coined by Thomas Huxley, the forefather of what became known later as “Social Darwinism,” since the individual seemingly draws no advantage for his own survival from it. However, examples of this kind of behavior abound among humans, whom we constantly see engaging in strong, diverse, and repeated forms of collaboration, often costly or risky, which extend well beyond the limited circle of relatives to individuals without any kinship to them.10
Darwin noted the existence of altruistic behavior in situations where it turned out to be useful to the group, but useless to the individual, as in the case of sterile workers in a society of insects. He found himself, he said, faced with “by far the most serious special difficulty, which my theory has encountered.”11 Natural selection should “never produce in a being anything injurious to itself, for natural selection acts solely by and for the good of each.”12 In order to exist, then, altruism must have a fundamental usefulness for the species:
In however complex a manner this feeling may have originated, as it is one of high importance to all those animals which aid and defend each other, it will have been increased, through natural selection; for those communities, which included the greatest number of the most sympathetic members, would flourish best, and rear the greatest number of offspring.13
Theoreticians who developed and completed Darwin’s ideas have always come up against the question of altruism. The question posed a thorny problem for them, since a priori it seemed that an individual who behaved in a completely selfish way had an advantage in the “struggle for life.” The egoist would unhesitatingly appropriate food and other limited resources for himself, would brutally oust his potential rivals at the time of reproduction, and would not hesitate to kill altruists if that favored his survival. Because of this, it was hard to see how genes that manifested in an altruistic temperament could have become implanted in any sort of population.
From this perspective, willingly giving the other an advantage seems to be a major counter-indication to the optimization of the individual’s chances of survival. Altruists should logically be the eternal losers in the struggle for life. However, that is far from the reality.
We have thus far defined altruism as a mental state, a motivation, an intention to fulfill others’ needs, a desire to do good for them or spare them suffering. Elliott Sober calls this motivation “psychological altruism” as opposed to “evolutionary altruism.” We should keep in mind, though, in this chapter, that when evolutionists speak of “altruism,” they are not interested in motivation, but solely in prosocial behavior—that is, in behavior that is beneficial to other individuals, and that entails a greater or lesser cost to their agents.14
For an evolutionist, the term “altruist” can be applied to sterile worker ants whose behavior benefits the ant colony, or else to a bird that emits an alarm call at a predator’s approach, allowing its fellows to flee to a safe place, but drawing the raptor’s attention to itself—a behavior that is often deadly for it. According to the view of survival of the fittest, such sacrificial behavior doesn’t make sense, since, by prematurely losing their lives, these “altruists” leave behind fewer descendants than the survivors. Such behavior should be naturally eliminated over the course of generations. Even bacteria, according to Dugatkin, can be regarded as “altruistic,” if their behavior leads to a diminution of their potential for reproduction while still being beneficial to that of other bacteria.15
This misappropriation by evolutionists of the terminology usually used to designate motivations is regrettable, since it continues to create pointless confusion. It would have been preferable for evolutionists to use other terms, such as “beneficial,” “useful,” “advantageous,” or “favorable” to others, for instance, in order to prevent their discussions on the nature of evolutionary altruism from influencing our vision of real altruism in human nature, as so often happens.
The problem of “evolutionary altruism” would eventually be clarified to some extent by a young English student fascinated by the question of altruism. In the 1960s, at Cambridge University, William Donald Hamilton decided, against everyone’s wishes, to concentrate in the genetic evolution of altruistic behavior. Solitary and shy, Hamilton didn’t even ask for a desk or an office. He worked at home, in libraries, and even on train station benches when the libraries were closed. He faced repeated criticisms from his professors and even considered terminating the course of his scientific career. But he persevered and published two articles, one in 1963, the other in 1964, which were received with complete indifference.16 His thesis advisers, who were of the opinion that he didn’t deserve his doctorate in science, refused to award it to him until 1968. However, these two articles would profoundly influence the science of evolution. In them, Hamilton describes, with the help of a relatively simple equation, what would be regarded as one of the great discoveries of the twentieth century in the field of evolution.17
Darwin spoke of the transmission of hereditary “traits” that were more or less favorable to the survival of the individual, hence to his ability to engender descendants who would bear that individual’s traits. Hamilton demonstrated that engendering the greatest possible number of descendants was not the only way to ensure the transmission of one’s genes to future generations. The same objective can be reached if close relatives, who also carry some of the genes, reproduce.
In his two articles, Hamilton proposes an equation, which has since become famous, that accounts for what we now call “kin selection,” by which behavior that helps a genetically related individual is favored by natural selection. Until then, the “reproductive success” of an individual was measured by the number of that individual’s descendants. But Hamilton showed that this selective value is not only commensurate with the success of the individual himself, but also with the success of all those who are genetically related to him, his brothers and sisters, nieces and nephews. In fact, they too carry a part of the genes of the individual in question (the sister of a given individual has an average of 50% of genes in common with him, a first cousin, 25%, a niece, 12.5%, and so on).
The overall reproductive success (or else the selective overall value called inclusive fitness by Hamilton) is then the sum of his direct reproductive success (his descendants) and his indirect reproductive success (that of his parents, who carry part of his genes). In the final analysis, what matters is the overall quantity of copies of our genes transmitted to the next generation, directly or indirectly.
Altruistic behavior in certain animals seemed suddenly to take on meaning from the evolutionary perspective. Hamilton’s equation formalized the intuition of the great geneticist J.B.S. Haldane, according to which it is worth giving one’s life to save the lives of at least two brothers or sisters, or four cousins, or eight nephews or nieces. If a wolf sacrifices itself by breaking away from the pack when it’s being pursued by hunters in order to attract attention to itself, saving the lives of a sufficient number of its brothers and sisters, nieces and nephews, who carry its genes and who can reproduce, then its sacrifice represents a clear benefit for the propagation of its own genes.
Since then, Hamilton’s equation has been verified many times in nature, in more complex situations. It has been demonstrated that among a species of ground squirrel, the Belding spermophile, for instance, individuals that most often give the alarm at the approach of a predator—very risky behavior, since when the predator catches its prey, in half the cases, it’s the unfortunate individual that gave the alarm—are those who have the greatest number of relatives in the immediate surroundings.18
In 1965, the great specialist in social insects Edward O. Wilson discovered Hamilton’s work and contributed greatly to its diffusion in the scientific community. Hamilton’s equation was verified in a spectacular way in eusocial insects like ants (which alone comprise half the biomass of all insects), certain bees, and other Hymenoptera.19
It follows from all this that a mutation predisposing behavior of the “evolutionary altruism” kind is favored by natural selection (and not penalized as previously thought) provided that the cost of the act borne by the “altruistic” individual is less than the corresponding gain for the propagation of his genes by his relatives.
Before he was recognized as a brilliant innovator, William D. Hamilton was joined in his intellectual quest, which till then had been solitary, by a man named George Price.20 Born in a poor family, son of an electrician and an opera singer, George Price studied chemistry, then at the age of twenty was recruited by the Manhattan Project, which was developing the atomic bomb. He worked for a time for IBM as an inventor, then emigrated to London. In a library, he came upon some articles by Hamilton. They intrigued him, and he wrote to Hamilton. Thus began a correspondence that led George Price, who initially was a novice in the field of evolution, to construct mathematical models to explain not only cooperation and altruistic behavior, but also intimidation, aggressiveness, and behavior that was generally harmful.
Finally, after some other exchanges with Hamilton, George Price formulated an equation, called the “covariance” equation, which accounted for various types of behavior, benevolent and malevolent, and for observations made in the animal world according to which altruistic behavior decreases when one goes from the immediate family to the group, and then changes into aggressiveness between individuals of different groups. Price showed too that, given adequate conditions, altruistic behavior could develop within a group of individuals.
As was the case for Hamilton, Price’s ideas were at first ignored. The article he sent to the journal Nature was rejected and, even though they ended up accepting it, it was solely because Hamilton refused to publish his next article21 until Price’s was published, explaining that he was basing the developments of his new article on Price’s equation. The article, called “Selection and Covariance,”22 was therefore published, but no one paid any attention to it. Hamilton seemed to be the only person who understood its importance at the time. Years later, Price’s contribution was recognized as one of the major breakthroughs of the twentieth century in evolution.
For over 98% of human history, our ancestors lived as hunter-gatherers,23 in small cooperative tribes. The children were raised with the help of members of the extended family and, usually, of the tribe as a whole. Both sexes took part in the search for food, with men hunting and women gathering edible plants.24 These societies were based on reciprocity and cooperation.
In 1971, Robert Trivers suggested that the creation of long-term relationships of exchange and mutual aid can facilitate reproduction and survival for each individual. Those who respect the law of reciprocity will derive long-term advantages from it that those who go it alone will not. According to his theory of “reciprocal altruism,” it is therefore in the interest of individuals to help each other over the long term, even if they are not related. Although Trivers was not concerned with motivations and did not address the question of “psychological altruism,” the theory of reciprocal altruism enlarges the circle of beneficial behavior, if one compares it to Hamilton’s theory, which concerns only individuals genetically related. According to Trivers, reciprocal altruism is likely to have evolved among species with relatively long lifespans who are interdependent, know each other well enough to be able to distinguish a trustworthy individual and one apt to return the favor from some other individual who is only an unprincipled profiteer. Such species also have an egalitarian organization, and are collectively involved in the care of their young.25
The research carried out by Kim Hill on the Ache tribes in the mountains of Paraguay have shown that 10% of the time spent gathering food by men and women in fact helps members of the tribe not related to them, but who themselves helped others. It also appears that, more than the degree of relation, it’s concern for fairness and taking into consideration the actual needs of each individual that govern the sharing of food. Such a reciprocity has even more meaning among the Ache since the provisioning of food is irregular and chancy. Reciprocal altruism thus comprises a form of insurance for periods when food is scarce. Here again, researchers focus on altruistic behavior, not on the motivation underlying such behavior.
Kim Hill and her colleagues also examined the social structures of groups of hunter-gatherers who still survive to this day throughout the world. Hill saw that because of the propensity of children of both sexes to leave the family home, most members of these communities are more often friends than relatives. The emergence of kindness to strangers thus seems to have appeared among humans not via the intermediary of genes (as one would expect if Hamilton’s model were applied to humans, which, obviously, is not the case), but as the result of the gradual evolution of cultures.26
In 1976, Richard Dawkins published a book that met with great success, The Selfish Gene, in which he explains that the most fundamental aspect of the process of evolution is not the survival of individuals, but that of genes.27 Dawkins’ main contribution was to show that Darwinian selection and competition are not exercised at the level of species or even of individuals, but at the level of the fundamental replicators of heredity, which are the DNA molecules that make up genes. Dawkins expresses this idea unambiguously when he writes, “We are survival machines—robot vehicles blindly programmed to preserve the selfish molecules known as genes.”28
Whereas Darwin saw the possibility for sympathies “to extend to the men of all nations and races,” even “beyond the confines of man,” that is, to animals, Dawkins leaves us with no illusions:
The argument of this book is that we, and all other animals, are machines created by our genes.… I shall argue that a predominant quality to be expected in a successful gene is ruthless selfishness. This gene selfishness will usually give rise to selfishness in individual behavior. However, as we shall see, there are special circumstances in which a gene can achieve its own selfish goals best by fostering a limited form of altruism at the level of individual animals.… Much as we might wish to believe otherwise, universal love and the welfare of the species as a whole are concepts that simply do not make evolutionary sense.29
Dawkins is of course not opposed to the idea of creating a better world, but he thinks that we are not naturally predisposed to do so and that, to attain that objective, we have nothing working in our favor:
If there is a human moral to be drawn, it is that we must teach our children altruism, for we cannot expect it to be part of their biological nature.30
As we will see in the chapter devoted to animals and childhood, that is not at all what emerges from research, for example the research of Felix Warneken and Michael Tomasello, in which they conclude: “Our claim is thus that the altruistic tendencies seen in early human ontogeny reflect a natural predisposition.” The fact that not only humans, but also chimpanzees, help each other altruistically also indicates that “The phylogenetic roots of human altruism—at least in the form of instrumental helping—may reach as far back as to the last common ancestor of humans and chimpanzees some six million years ago.”31
Although the stress Dawkins placed on the central role of genes in the evolutionary process does not lend itself to controversy, the use of psychological terms in his book to designate processes of an entirely different order is unfortunate. The very title of Dawkins’ book—The Selfish Gene—no doubt contributed to its success: what would have become of the book if it had been called On the Self-Perpetuation of Genes? Still, according to the great ethologist Jane Goodall, this book became a bestseller “in part, I think, because for many people it provided an excuse for human selfishness and cruelty. It was just our genes. We couldn’t help it… It was comforting perhaps to disclaim responsibility for our bad behavior.”32
As Frans de Waal notes, “Genes can’t be any more ‘selfish’ than a river can be ‘angry,’ or sun rays ‘loving.’ Genes are little chunks of DNA.”33 Even if Dawkins claims that he “is not interested in the psychology of motivations,” by using a term like “selfishness,” which inevitably evokes a motivation, he only aggravates the confusion that already reigned over the question of the nature of altruism.
This ambiguity did not fail to strike the imagination and to provide a justification for some of the most self-serving and selfish behavior of our time. Frans de Waal cites the case of the Enron company, which went bankrupt thanks to embezzlement: “The company’s CEO, Jeff Skilling—now in prison—was a great fan of Richard Dawkins’ The Selfish Gene, and deliberately tried to mimic nature by instigating cutthroat competition within his company.”34
In fact, Skilling set up a system of internal evaluation among colleagues, who were ordered to evaluate each other. Then he fired anyone who got a weak score. Up to 20% of employees were turned away every year, after they had been humiliated on an Internet site where unflattering portraits of them were posted. To be able to survive in the world of Enron, you had to relentlessly attack/hound your colleagues!
Despite its remarkable consonance with many eusocial insects, Hamilton’s theory fails spectacularly to explain human behavior, and, generally, any behavior characterized by a high level of cooperation independent of blood relationship. Humans are, in fact, capable of enlarging the circle of their altruism not only to include other non-related humans, but also to other non-human species, which is even less conceivable from the perspective of kin selection.
A science journalist for the British newspaper The Guardian wrote about the 180 Japanese workers in the Fukushima nuclear plant who continued working for months up to fifty hours in a row in order to cool down the damaged reactors, thus voluntarily exposing themselves to radiation levels that were seriously harmful to their health:
Although kin selection works well in the animal kingdom it seems an unlikely mechanism to account for human altruism and co-operation. A Japanese nuclear plant worker who wanted to benefit his genes would serve them better by buying train tickets to take himself and all his relatives far from Fukushima.35
As for animals that take care of other species, like the tigress in the Calcutta zoo that suckled a litter of orphaned piglets instead of devouring them, Richard Dawkins declared in a televised documentary that this was a case of “a misfiring of selfish genes.”
Not only are genes supposed to be “selfish,” but in order to be faithful to them, we are supposed to behave solely in a selfish way. However, while still remaining in agreement with the Darwinian principles of evolution, extended altruism is fully explicable by taking into account the basic role of cooperation in evolution. That, in any case, is what emerges from recent discoveries in the field of evolution, which combine a considerable mass of observations about animal behavior with new mathematical models on the dynamic of populations.
E. O. Wilson was, as we have seen, one of the great promoters of the theory of kin selection. “I must say that I’ve had to concede that Hamilton—even though I think I knew more about social insects—beat me to it to produce the main idea, the most original, important idea, on social insects of this century,”36 Wilson wrote in 1971. For forty years, this theory based on the importance of kinship has dominated evolutionist thinking. Today, having reached the summit of a long and distinguished career as a researcher, E. O. Wilson thinks he was mistaken: he is now convinced that it is generalized cooperation, compatible with classical Darwinian selection, that explains the emergence and success of social species, as the title of his most recent book attests: The Social Conquest of Earth.37
Other voices, those of eminent geneticists like Luca Cavalli-Sforza and Marcus Feldman, had, starting in the 1970s, drawn attention to the limitations of Hamilton’s theory in explaining altruism.38 His successors have tended to regard kin selection as being the universal principle of evolution, and have tried to make everything factor into this theory as well as they could, including altruistic cooperation. Over the years, Wilson also developed growing doubts about the validity of this theory. These doubts crystallized when he began collaborating with Martin Nowak, biologist, mathematician, and Director of the Program for Evolutionary Dynamics at Harvard. Wilson thought that Hamilton’s theory was brilliant mathematically, but increasingly doubted its applications to the real world as practical observations, ever more numerous, came to contradict it. Nowak, on the contrary, was of the mind that Hamilton’s theory was indeed verified in nature, but, from the mathematical point of view, he deemed it obscure and limited. Their meeting contributed to “a mutual liberation.”39
Nowak and Corina Tarnita, a brilliant mathematician on the Harvard team, conceived of a more rigorous mathematical model, based on the classic Darwinian concept of natural selection, which encompasses kinship relationships, when they are involved, as well as the cooperative behavior involved in evolution. This model, based on the dynamics and genetics of populations, takes into account the variety of interactions that occur within a population, on both the individual and collective level.40
The necessity for this new formulation was twofold: to provide a theory that transcends the limitations of Hamilton’s theory concerning “extended altruism,” and to take into account the increasing number of exceptions to the theory of kin selection. Two wasp specialists, notably—James Hunt, at North Carolina State University, and Raghavendra Gadagkar, at the Indian Institute of Science in Bangalore—discovered that kin selection did not apply to the species they were studying.41 Philip Johns and his collaborators also showed that after an antagonistic encounter between two non-related colonies of termites, the survivors of each colony cooperated successfully, forming a single colony.42
In particular, according to Wilson, the main factor that leads to the appearance of large animal societies (eusociality) is not fundamentally the link of kinship, but the building of “nests”—understood here in the wider sense of collective places for habitation and reproduction, an underground anthill, for instance—which can be defended and in which several generations of young are raised. When a female, the queen of an anthill, for instance, and her adult descendants remain in the nest to look after the next generations, a eusocial community can thus be established. The kinship links existing in such a community would thus not be the necessary cause (as Hamilton thought), but one of the consequences of the formation of this community. In brief, kinship links are useful, but not necessary, and we are now aware of many examples of eusocial colonies comprised of non-related individuals.43
The mathematical explanatory model by Nowak, Tarnita, and Wilson roused a storm of controversy in the field of evolutionists who, for several decades, have centered their vision of evolution on kin selection. An intense exchange of publications and arguments ensued in the scientific journal Nature, and the debate is still continuing today.44 Still, this model brings new arguments to the idea of natural selection operating on multiple levels: that of individuals, that of groups of individuals, and that of cultures which influence the behavior of these groups.
Ever since Darwin, the idea that natural selection could favor or place at a disadvantage not only individuals, and more specifically their genes, but also the group of individuals which could be regarded as itself an entity, has met with varied reactions and continues to give rise to endless debate. Envisaged by Darwin, it was dismissed at the end of the 1960s,45 brought back by Hamilton and Price in 1975 without much success, and finally reformulated with new arguments by David Sloan Wilson, Elliott Sober,46 E. O. Wilson, and Martin Nowak.
Generally, a group is defined here as a collection of individuals constituted over a certain period of time during which they mutually influence their future (and their reproductive success).47 Bees in a hive, for instance, have more influence over the fate of the other inhabitants of their own hive than on those of a neighboring hive. This group can have a varying duration of existence, from a few days to a whole lifetime. A dozen explorers preparing to leave in search of treasure in a jungle in Central America comprise such a group: they can all draw benefits from it and they will also all expose themselves to danger. The actions of each member will have repercussions on the fate of all the others.48
Selective pressure occurs at all levels of the organization of life, from the cells of a multicellular organism to ecosystems, from individuals to groups. Group selection does not in any way oppose individual selection, but it goes beyond its limitations. Essentially, when individuals are all in competition with each other, those who cooperate the least and profit the most from the kindness of others succeed best, but when it is groups that enter into competition, the aptitude of groups to cooperate is a determining asset: strongly cooperative groups survive better than other groups.49
According to the mathematical models presented by David Wilson and Sober, groups that contain a majority of altruistic individuals prosper because of the advantages that cooperation and mutual aid bring to the group as a whole, despite the presence of a certain number of selfish individuals, or freeriders, that profit from the altruism of others. The members of this group will thus have more descendants, the majority of whom will exhibit altruistic behavior.
Groups containing a majority of selfish individuals do much less well, because the dominant attitude of “everyone for himself” harms the overall success of the community. In such a group, the minority altruists are less favored, and find themselves too isolated for their spirit of cooperation to influence the others. One on one, selfish individuals may have an advantage here over altruistic individuals, but their group stagnates as a whole, and will thus produce fewer descendants.
If this pattern is repeated from generation to generation, the proportion of individuals bearing the altruistic trait will increase. The lesson of this model, tested mathematically over a large number of generations, is encouraging: once the percentage of altruists in a population surpasses a certain threshold (which could be around 20% of the population), the altruistic characteristic is amplified over the course of generations.50
In collaboration with Sober and Wilson, Martin Nowak and Corina Tarnita have pinpointed the conditions that allow altruistic cooperation to prosper. It turns out, in fact, that human societies can be described in terms of collections of people who share certain interests, values, and activities. The more points you have in common with someone, the more you will interact with him, and the more your shared interests will encourage you to cooperate.
The eternal problem, in a community of cooperating individuals, is the presence of profiteers, whom economists call “freeriders,” who profit from the kindness of cooperators in order to use them and get the best of the deal. When the majority of people trust each other and cooperate, freeriders can easily exploit others. And when their number increases too much, the community declines. Thus the rate of trust and cooperation will fluctuate over time.
Little by little, cooperators will tend to find each other and to work together, while groups where freeriders are predominant will decline with time. Fluctuations will still be repeated, however, since new freeriders will regularly introduce themselves into a group of prospering cooperators.51
By testing various mathematical models over hundreds of virtual generations, Nowak and his collaborators have shown that, aside from mobility, the success of cooperation depended in the end on the frequency with which cooperators associated with each other. If this frequency is higher than the frequency with which freeriders collude with other freeriders, altruistic cooperators will become the majority. In short, in order to progress toward a more altruistic society, it is essential that altruists associate with each other and join forces. In our time, this synergy between cooperators and altruists no longer requires them to be gathered together in the same geographical location, since contemporary means of communication, social networks in particular, allow the emergence of movements of cooperation joining together large numbers of people who are geographically scattered.