As we better understand the brain, we will increasingly understand all of the forces—kindness, reciprocity, trust, openness to argument, respect for evidence, intuitions of fairness, impulse control, the mitigation of aggression, etc.—that allow friends and strangers to collaborate successfully on the common projects of civilization. Understanding ourselves in this way, and using this knowledge to improve human life, will be among the most important challenges to science in the decades to come.
Many people imagine that the theory of evolution entails selfishness as a biological imperative. This popular misconception has been very harmful to the reputation of science. In truth, human cooperation and its attendant moral emotions are fully compatible with biological evolution. Selection pressure at the level of "selfish" genes would surely incline creatures like ourselves to make sacrifices for our relatives, for the simple reason that one's relatives can be counted on to share one's genes: while this truth might not be obvious through introspection, your brother's or sister's reproductive success is, in part, your own. This phenomenon, known as kin selection, was not given a formal analysis until the 1960s in the work of William Hamilton, 3 but it was at least implicit in the understanding of earlier biologists. Legend has it that J. B. S. Haldane was once asked if he would risk his life to save a drowning brother, to which he quipped, "No, but I would save two brothers or eight cousins." 4
The work of evolutionary biologist Robert Trivers on reciprocal altruism has gone a long way toward explaining cooperation among unrelated friends and strangers. 5 Trivers's model incorporates many of the psychological and social factors related to altruism and reciprocity, including: friendship, moralistic aggression (i.e., the punishment of cheaters), guilt, sympathy, and gratitude, along with a tendency to deceive others by mimicking these states. As first suggested by Darwin, and recently elaborated by the psychologist Geoffrey Miller, sexual selection may have further encouraged the development of moral behavior. Because moral virtue is attractive to both sexes, it might function as a kind of peacock's tail: costly to produce and maintain, but beneficial to one's genes in the end. 6
Clearly, our selfish and selfless interests do not always conflict. In fact, the well-being of others, especially those closest to us, is one of our primary (and, indeed, most selfish) interests. While much remains to be understood about the biology of our moral impulses, kin selection, reciprocal altruism, and sexual selection explain how we have evolved to be, not merely atomized selves in thrall to our self-interest, but social selves disposed to serve a common interest with others. 7
Certain biological traits appear to have been shaped by, and to have further enhanced, the human capacity for cooperation. For instance, unlike the rest of the earth's creatures, including our fellow primates, the sclera of our eyes (the region surrounding the colored iris) is white and exposed. This makes the direction of the human gaze very easy to detect, allowing us to notice even the subtlest shifts in one another's visual attention. The psychologist Michael Tomasello suggests the following adaptive logic:
If I am, in effect, advertising the direction of my eyes, I must be in a social environment full of others who are not often inclined to take advantage of this to my detriment—by, say, beating me to the food or escaping aggression before me. Indeed, I must be in a cooperative social environment in which others following the direction of my eyes somehow benefits me. 8
Tomasello has found that even twelve-month old children will follow a person's gaze, while chimpanzees tend to be interested only in head movements. He suggests that our unique sensitivity to gaze direction facilitated human cooperation and language development.
While each of us is selfish, we are not merely so. Our own happiness requires that we extend the circle of our self-interest to others—to family, friends, and even to perfect strangers whose pleasures and pains matter to us. While few thinkers have placed greater focus on the role that competing self-interests play in society, even Adam Smith recognized that each of us cares deeply about the happiness of others. 9 He also recognized, however, that our ability to care about others has its limits and that these limits are themselves the object of our personal and collective concern:
Let us suppose that the great empire of China, with all its myriads of inhabitants, was suddenly swallowed up by an earthquake, and let us consider how a man of humanity in Europe, who had no sort of connection with that part of the world, would be affected upon receiving intelligence of this dreadful calamity. He would, I imagine, first of all, express very strongly his sorrow for the misfortune of that unhappy people, he would make many melancholy reflections upon the precariousness of human life, and the vanity of all the labours of man, which could thus be annihilated in a moment. He would too, perhaps, if he was a man of speculation, enter into many reasonings concerning the effects which this disaster might produce upon the commerce of Europe, and the trade and business of the world in general. And when all this fine philosophy was over, when all these humane sentiments had been once fairly expressed, he would pursue his business or his pleasure, take his repose or his diversion, with the same ease and tranquility, as if no such accident had happened. The most frivolous disaster which could befall himself would occasion a more real disturbance. If he was to lose his little finger to-morrow, he would not sleep to-night; but, provided he never saw them, he will snore with the most profound security over the ruin of a hundred millions of his brethren, and the destruction of that immense multitude seems plainly an object less interesting to him, than this paltry misfortune of his own. To prevent, therefore, this paltry misfortune to himself, would a man of humanity be willing to sacrifice the lives of a hundred millions of his brethren, provided he had never seen them? Human nature startles with horror at the thought, and the world, in its greatest depravity and corruption, never produced such a villain as could be capable of entertaining it. But what makes this difference? 10
Smith captures the tension between our reflexive selfishness and our broader moral intuitions about as well as anyone can here. The truth about us is plain to see: most of us are powerfully absorbed by selfish desires almost every moment of our lives; our attention to our own pains and pleasures could scarcely be more acute; only the most piercing cries of anonymous suffering capture our interest, and then fleet-ingly. And yet, when we consciously reflect on what we should do, an angel of beneficence and impartiality seems to spread its wings within us: we genuinely want fair and just societies; we want others to have their hopes realized; we want to leave the world better than we found it.
Questions of human well-being run deeper than any explicit code of morality. Morality—in terms of consciously held precepts, social contracts, notions of justice, etc.—is a relatively recent development. Such conventions require, at a minimum, complex language and a willingness to cooperate with strangers, and this takes us a stride or two beyond the Hobbesian "state of nature." However, any biological changes that served to mitigate the internecine misery of our ancestors would fall within the scope of an analysis of morality as a guide to personal and collective well-being. To simplify matters enormously:
1. Genetic changes in the brain gave rise to social emotions, moral intuitions, and language ...
2. These allowed for increasingly complex cooperative behavior, the keeping of promises, concern about one's reputation, etc....
3. Which became the basis for cultural norms, laws, and social institutions whose purpose has been to render this growing system of cooperation durable in the face of countervailing forces.
Some version of this progression has occurred in our case, and each step represents an undeniable enhancement of our personal and collective well-being. To be sure, catastrophic regressions are always possible. We could, either by design or negligence, employ the hard-won fruits of civilization, and the emotional and social leverage wrought of millennia of biological and cultural evolution, to immiserate ourselves more fully than unaided Nature ever could. Imagine a global North Korea, where the better part of
a starving humanity serve as slaves to a lunatic with bouffant hair: this might be worse than a world filled merely with warring australopithecines. What would "worse" mean in this context? Just what our intuitions suggest: more painful, less satisfying, more conducive to terror and despair, and so on. While it may never be feasible to compare such counterfactual states of the world, this does not mean that there are no experiential truths to be compared. Once again, there is a difference between answers in practice and answers in principle.
The moment one begins thinking about morality in terms of well-being, it becomes remarkably easy to discern a moral hierarchy across human societies. Consider the following account of the Dobu islanders from Ruth Benedict:
Life in Dobu fosters extreme forms of animosity and malignancy which most societies have minimized by their institutions. Dobuan institutions, on the other hand, exalt them to the highest degree. The Dobuan lives out without repression man's worst nightmares of the ill-will of the universe, and according to his view of life virtue consists in selecting a victim upon whom he can vent the malignancy he attributes alike to human society and to the powers of nature. All existence appears to him as a cutthroat struggle in which deadly antagonists are pitted against one another in contest for each one of the goods of life. Suspicion and cruelty are his trusted weapons in the strife and he gives no mercy, as he asks none. 11
The Dobu appear to have been as blind to the possibility of true cooperation as they were to the truths of modern science. While innumerable things would have been worthy of their attention—the Dobu were, after all, extremely poor and mightily ignorant—their main preoccupation seems to have been malicious sorcery. Every Dobuan's primary interest was to cast spells on other members of the tribe in an effort to sicken or kill them and in the hopes of magically appropriating their crops. The relevant spells were generally passed down from a maternal uncle and became every Dobuan's most important possessions. Needless to say, those who received no such inheritance were believed to be at a terrible disadvantage. Spells could be purchased, however, and the economic life of the Dobu was almost entirely devoted to trade in these fantastical commodities.
Certain members of the tribe were understood to have a monopoly over both the causes and cures for specific illnesses. Such people were greatly feared and ceaselessly propitiated. In fact, the conscious application of magic was believed necessary for the most mundane tasks. Even the work of gravity had to be supplemented by relentless wizardry: absent the right spell, a man's vegetables were expected to rise out of the soil and vanish under their own power.
To make matters worse, the Dobu imagined that good fortune conformed to a rigid law of thermodynamics: if one man succeeded in growing more yams than his neighbor, his surplus crop must have been pilfered through sorcery. As all Dobu continuously endeavored to steal one another's crops by such methods, the lucky gardener is likely to have viewed his surplus in precisely these terms. A good harvest, therefore, was tantamount to "a confession of theft."
This strange marriage of covetousness and magical thinking created a perfect obsession with secrecy in Dobu society. Whatever possibility of love and real friendship remained seems to have been fully extinguished by a final doctrine: the power of sorcery was believed to grow in proportion to one's intimacy with the intended victim. This belief gave every Dobuan an incandescent mistrust of all others, which burned brightest on those closest. Therefore, if a man fell seriously ill or died, his misfortune was immediately blamed on his wife, and vice versa. The picture is of a society completely in thrall to antisocial delusions.
Did the Dobu love their friends and family as much as we love ours? Many people seem to think that the answer to such a question must, in principle, be "yes," or that the question itself is vacuous. I think it is clear, however, that the question is well posed and easily answered. The answer is "no." Being fellow Homo sapiens, we must presume that the Dobu islanders had brains sufficiently similar to our own to invite comparison. Is there any doubt that the selfishness and general malevolence of the Dobu would have been expressed at the level of their brains? Only if you think the brain does nothing more than filter oxygen and glucose out of the blood. Once we more fully understand the neuro physiology of states like love, compassion, and trust, it will be possible to spell out the differences between ourselves and people like the Dobu in greater detail. But we need not await any breakthroughs in neuro-science to bring the general principle in view: just as it is possible for individuals and groups to be wrong about how best to maintain their physical health, it is possible for them to be wrong about how to maximize their personal and social well-being.
I believe that we will increasingly understand good and evil, right and wrong, in scientific terms, because moral concerns translate into facts about how our thoughts and behaviors affect the well-being of conscious creatures like ourselves. If there are facts to be known about the well-being of such creatures—and there are—then there must be right and wrong answers to moral questions. Students of philosophy will notice that this commits me to some form of moral realism (viz. moral claims can really be true or false) and some form of consequentialism (viz. the Tightness of an act depends on how it impacts the well-being of conscious creatures). While moral realism and consequentialism have both come under pressure in philosophical circles, they have the virtue of corresponding to many of our intuitions about how the world works. 12
Here is my (consequentialist) starting point: all questions of value (right and wrong, good and evil, etc.) depend upon the possibility of experiencing such value. Without potential consequences at the level of experience—happiness, suffering, joy, despair, etc.—all talk of value is empty. Therefore, to say that an act is morally necessary, or evil, or blameless, is to make (tacit) claims about its consequences in the lives of conscious creatures (whether actual or potential). I am unaware of any interesting exception to this rule. Needless to say, if one is worried about pleasing God or His angels, this assumes that such invisible entities are conscious (in some sense) and cognizant of human behavior. It also generally assumes that it is possible to suffer their wrath or enjoy their approval, either in this world or the world to come. Even within religion, therefore, consequences and conscious states remain the foundation of all values.
Consider the thinking of a Muslim suicide bomber who decides to obliterate himself along with a crowd of infidels: this would appear to be a perfect repudiation of the consequentialist attitude. And yet, when we look at the rationale for seeking martyrdom within Islam, we see that the consequences of such actions, both real and imagined, are entirely the point. Aspiring martyrs expect to please God and experience an eternity of happiness after death. If one fully accepts the metaphysical presuppositions of traditional Islam, martyrdom must be viewed as the ultimate attempt at career advancement. The martyr is also the greatest of altruists: for not only does he secure a place for himself in Paradise, he wins admittance for seventy of his closest relatives as well. Aspiring martyrs also believe that they are furthering God's work here on earth, with desirable consequences for the living. We know quite a lot about how such people think—indeed, they advertise their views and intentions ceaselessly—and it has everything to do with their belief that God has told them, in the Qur'an and the hadith, precisely what the consequences of certain thoughts and actions will be. Of course, it seems profoundly unlikely that our universe has been designed to reward individual primates for killing one another while believing in the divine origin of a specific book. The fact that would-be martyrs are almost surely wrong about the consequences of their behavior is precisely what renders it such an astounding and immoral misuse of human life.
Because most religions conceive of morality as a matter of being obedient to the word of God (generally for the sake of receiving a supernatural reward), their precepts often have nothing to do with maximizing well-being in this world. Religious believers can, therefore, assert the immorality of contraception, masturbation, homosexuality, etc., wi
thout ever feeling obliged to argue that these practices actually cause suffering. They can also pursue aims that are flagrantly immoral, in that they needlessly perpetuate human misery, while believing that these actions are morally obligatory. This pious uncoupling of moral concern from the reality of human and animal suffering has caused tremendous harm.
Clearly, there are mental states and capacities that contribute to our general well-being (happiness, compassion, kindness, etc.) as well as mental states and incapacities that diminish it (cruelty, hatred, terror, etc.). It is, therefore, meaningful to ask whether a specific action or way of thinking will affect a person's well-being and/or the well-being of others, and there is much that we might eventually learn about the biology of such effects. Where a person finds himself on this continuum of possible states will be determined by many factors—genetic, environmental, social, cognitive, political, economic, etc.—and while our understanding of such influences may never be complete, their effects are realized at the level of the human brain. Our growing understanding of the brain, therefore, will have increasing relevance for any claims we make about how thoughts and actions affect the welfare of human beings.
Notice that I do not mention morality in the preceding paragraph, and perhaps I need not. I began this book by arguing that, despite a century of timidity on the part of scientists and philosophers, morality can be linked directly to facts about the happiness and suffering of conscious creatures. However, it is interesting to consider what would happen if we simply ignored this step and merely spoke about "well-being." What would our world be like if we ceased to worry about "right" and "wrong," or "good" and "evil," and simply acted so as to maximize well-being, our own and that of others? Would we lose anything important? And if important, wouldn't it be, by definition, a matter of someone's well-being?