Science of Good and Evil Read online

  Subsequent to Darwin, group selection was occasionally invoked until the mid-1960s, when the highly influential evolutionary biologist George C. Williams published his widely read book Adaptation and Natural Selection, in which he demonstrated that natural selection at the individual level was all that was needed to explain nature’s diversity, including human social and moral behavior. Since the 1960s, group selection was vilified as the pap of bleeding-heart liberals who couldn’t deal with the reality of “nature red in tooth and claw.” Evolutionary theorist Michael Ghiselin described the “economy of nature” as competitive exclusively at the individual level: “The impulses that lead one animal to sacrifice himself for another turn out to have their ultimate rationale in gaining advantage over a third … . Given a full chance to act in his own interest, nothing but expediency will restrain him from brutalizing, from maiming, from murdering—his brother, his mate, his parent, or his child. Scratch an ‘altruist,’ and watch a ‘hypocrite’ bleed.”32

  In the late 1990s, however, group selection made something of a comeback. In their 1998 book Unto Others, anthropologist David Sloan Wilson and his colleague, philosopher Elliott Sober, demonstrated through a sophisticated mathematical model and a series of logical arguments that group selection is viable. They began by defining a group as “a set of individuals that influence each other’s fitness with respect to a certain trait but not the fitness of those outside the group.” They then explained how “individual selection favors traits that maximize relative fitness within single groups,” and that “group selection favors traits that maximize the relative fitness of groups.” In this model, “altruism is maladaptive with respect to individual selection but adaptive with respect to group selection.” Therefore, they conclude, “altruism can evolve if the process of group selection is sufficiently strong.”33 For example, they cite William Hamilton’s analysis of how consciousness might have provided a group selective advantage for certain human populations with regard to the ethical enforcement of rules: “The more consciences are lacking in a group as a whole, the more energy the group will need to divert to enforcing otherwise tacit rules or else face dissolution. Thus considering one step (individual vs. group) in a hierarchical population structure, having a conscience is an ‘altruistic’ character.”34 The reason individual selection will not work becomes apparent in this thought experiment proposed by David Sloan Wilson:

  Imagine a population that consists of solid citizens and shirkers. The solid citizens produce a public good that is available to everybody, including themselves. For purposes of the example, let’s say that the public good can be produced at no cost to the solid citizens. Not only do they share the bounty, but they lose nothing by creating it. Even so, the solid citizens will not be favored by natural selection in this example because the solid citizens and shirkers do not differ in their survival or reproduction. Natural selection requires differences in fitness so raising or lowering the fitness of everyone in the population has no effect. If, as seems likely, the public good is costly to produce, the solid citizens will go extinct, even if they share the benefits, because their private cost reduces their fitness relative to the shirkers. Behaviors that are “for the good of the group” are at best neutral (if the public good is cost-free) and at worst maladaptive (if there is any cost associated with producing the public good).

  Wilson calls this “the fundamental problem of social life” and provides the following group selection solution:

  Imagine not one but many populations that vary in their proportions of solid citizens and shirkers. Even if shirkers fare better than solid citizens within each population, populations with an excess of solid citizens fare better than populations with an excess of shirkers. In short, there is a process of natural selection at the group level that favors solid citizens, just as there is a process of natural selection at the individual level (within each group) favoring shirkers. Group-level adaptations will evolve whenever group-level selection is stronger than individual-level selection.35

  Part of the problem in this debate is the all-too-human tendency to dichotomize. Instead of viewing this as a forced choice between individual selection and group selection, we can readily adopt a hierarchical theory of evolution, where we recognize and acknowledge both forces at work. A second challenge is in how we define certain terms, such as altruism and cooperation, and the temptation to force these categories into either-or choices, where people are (generally/situationally /purely) altruistic or selfish, cooperative or competitive. As descriptive terms, altruistic and cooperative are not reified things; they are behaviors. And like all behaviors, there is a broad range of expression, from a little to a lot. Here again a fuzzy logic analysis helps clarify this complex human phenomenon. Depending on the circumstances, some people in some situations are .2 altruistic and .8 nonaltruistic (or selfish), or .6 cooperative and .4 noncooperative (or competitive). Fuzzy fractions apply to individual and group selection as well. Individuals and groups can be altruistic and nonaltruistic, cooperative and noncooperative in degrees of expression changing over varying circumstances. It all depends on the situation. In this context, it might be useful to settle the group selection debate, at least provisionally, by acknowledging that group selection might work in a limited set of circumstances for some species. Group selection is not in opposition to individual selection; it is complementary, giving whole populations a selective advantage over other whole populations.

  In applying group selection to the origins of religion, Wilson argues that “Religions exist primarily for people to achieve together what they cannot achieve alone. The mechanisms that enable religious groups to function as adaptive units include the very beliefs and practices that make religion appear enigmatic to so many people who stand outside of them.” Going inside religion, Wilson argues, allows us to see what their practical function is—the group itself becomes a living organism, subject to the forces of natural selection. “Through countless generations of variation and selection, they acquire properties that enable them to survive and reproduce in their environments.”36 He notes as support, for example, anthropological studies of meat sharing practiced by all modern hunter-gatherer communities around the world. It turns out that these small bands and tribes—which can cautiously be used as a model for our own Paleolithic ancestors—are remarkably egalitarian. Using portable scales to precisely measure how much meat each family within the group received after a successful hunt, anthropologists discovered that the immediate families of successful hunters got no more meat than the rest of the families in the group, even when this was averaged over several weeks of regular hunting excursions. “Hunter-gatherers are egalitarian, not because they lack selfish impulses but because selfish impulses are effectively controlled by other members of the group,” Wilson explains. “In human hunter-gatherer groups, an individual who attempts to dominate others is likely to encounter the combined resistance of the rest of the group. In most cases even the strongest individual is no match for the collective, so self-serving acts are effectively curtailed.”37

  How gossip, morality, and group selection link together can be seen in studies of a number of hunter-gatherer societies. Anthropologist Chris Boehm, for example, has demonstrated the use of gossip to ridicule, shun, and even ostracize individuals whose competitive drives and selfish motives interfere with the cooperative needs and altruistic tendencies of the group. In other words, people are competitive and selfish, and individual selection has created these important and powerful drives. But people are also cooperative and altruistic, and these drives are created and reinforced by the group in which the individual lives. Thus, an emotional sense of “right” and “wrong” action is ingrained into individuals back to the earliest days in human evolutionary history, through genetic transmission of such traits supplemented by culture transmission through modeling and learning. A moral “sense,” then, need not be culturally codified in some formal fashion (for example, in writing), or even be a conscious effort on the p
art of individuals. “Good” and “bad” behaviors are rewarded and punished by the group, individuals succeed or fail as members of the group depending on their moral or immoral behaviors, and groups with more moral individuals than immoral individuals gain a collective advantage over other groups who are less successful at fostering a healthy balance between cooperation and competition, altruism and selfishness.

  An anthropological example of how this process works can be seen in the Malaysian rain forest tribe called the Chewong. Like other hunter-gatherer groups, the Chewong (who also employ limited agriculture) are egalitarian, a way of life that is governed by a system of superstitions called punen. In the words of anthropologist Signe Howell, who conducted an extensive ethnography of the Chewong, punen is “a calamity or misfortune, owing to not having satisfied an urgent desire.” In the Chewong world, for example, strong desires are connected with food, and powerful norms about food sharing are associated with the mythical being Yinlugen bud, who supposedly brought the Chewong out of a more primitive state by insisting that eating alone was improper human behavior. Myth, gods, religion, and morality are all integrated in the Chewong culture through the concept of punen and are linked to a very practical matter of individual and group survival: eating and sharing food. Thus, the Chewong avoid provoking punen at all costs. When game is caught away from the village, it is promptly returned, publicly displayed, and equitably distributed among all households and even among all individuals within each home. To reinforce the sanction against punen, someone from the hunter’s family touches the catch and then proceeds to touch everyone present, repeating the word punen. In this system, religious superstitions and gods oversee the exchange process, generating within the individuals an overall sense of right and wrong action as related to the success or failure of the group.38

  The Psychology of Morality: Emotions, Tipping, and the Prisoner’s Dilemma

  At the foundation of the Bio-Cultural Evolutionary model is an evolved moral sense. By a moral sense, I mean a moral feeling or emotion generated by actions. For example, positive emotions such as righteousness and pride are experienced as the psychological feeling of doing “good.” These moral emotions likely evolved out of behaviors that were reinforced as being good either for the individual or for the group. Negative emotions such as guilt and shame are experienced as the psychological feeling of doing “bad.” These moral emotions probably evolved out of behaviors that were reinforced as being bad either for the individual or for the group. This is the psychology of morality—the feeling of being moral or immoral. These moral emotions represent something deeper than specific feelings about specific behaviors. While cultures may differ on what behaviors are defined as good or bad, the general moral emotion of feeling good or feeling bad about behavior X (whatever X may be) is an evolved emotion that is universal to all humans.

  Consider some of the more basic emotions that represent something deeper than specific feelings. When we need to eat we do not compute caloric input/output ratios; we simply feel hungry. That feeling is an evolved hunger sentiment that triggers eating behavior. When we need to procreate to pass on our genes into the next generation we do not calculate the genetic potential of our sexual partner, we just feel horny and seek out a partner we find attractive. The sexual urge—the undeniably powerful feeling of wanting to have sex—is an evolved sexual sentiment that triggers sexual behavior. In other words, we are hungry and horny because, ultimately, the survival of the species depends on food and sex, and those organisms for whom healthy foods tasted good and for which sex was exquisitely delightful left behind more offspring. To be blunt, we are the descendants of hungry and horny hominids.

  Theists often ask, “If there is no God why should we be moral?” In this evolutionary theory of morality, asking “Why should we be moral?” is like asking “Why should we be hungry?” or “Why should we be horny?” For that matter, we could ask, “Why should we be jealous?” or “Why should we fall in love?” The answer is that it is as much a part of human nature to be moral as it is to be hungry, horny, jealous, and in love.

  Again, to punch home the important distinction between the how and the why in the search for the origins of morality, specific behaviors in a culture may be considered right or wrong and these vary over cultures and history. But the sense of being right or wrong in the emotions of righteousness and pride, guilt and shame, is a human universal that had an evolutionary origin. There is variation within human populations on this evolved trait, just as there is variation in any personality trait, where some people feel more or less guilt or more or less pride than others. This variation, like the variation in personality traits, is accounted for by roughly half genetics and half environment.

  Consider tipping at a restaurant in a city where you have never been and will never return. Since I travel a fair amount for my work I am faced with this moral question nearly every trip: why should I bother to tip a restaurant server I will never see again? There is no anticipated reciprocity since the tip comes after the service. I often dine alone so there is no one to impress with my generosity. Since I do not believe in God my answer cannot be “because God will know.” (Even if you are a believer this seems like a rather shallow reason in any case.) Ethical egoism theory states that I will leave a tip because it makes me feel good. That is, tipping is not an altruistic act at all, but a purely selfish one. But what does it mean to feel good about an act, regardless of whether we consider it selfish or altruistic? In my theory this sense of feeling good about doing something good for someone else is an evolved moral sense that has a perfectly reasonable evolutionary explanation. Humans practice both deception and self-deception. Research shows that we are better at deception than at deception detection, but deceivers get caught often enough that it is risky to attempt to deceive others. Research also shows that the normal cues we give off when we are attempting to deceive others (particularly nonverbal cues like taking a deep breath, looking away from the person you are talking to, hesitating before answering, and so forth) are less likely to be expressed if you actually believe the deception yourself.39 Liars are not liars if they believe the lie. This is the power of self-deception.

  It is not enough to fake doing the right thing in order to fool our fellow group members, because although we are fairly good deceivers, we are also fairly good deception detectors. We cannot fool all of the people all of the time, and we do learn to assess (through gossip, in part) who is trustworthy and who is not trustworthy, so it is better to actually be a moral person because that way you actually believe it yourself and thus there is no need for deception. What I am saying is that the best way to convince others that you are a moral person is not to fake being a moral person but to actually be a moral person. Don’t just go through the motions of being moral (although this is a good start), actually be moral. Don’t just pretend to do the right thing, do the right thing. It is my contention that this is how moral sentiments evolved in our Paleolithic ancestors living in small communities.

  Modern game theory grants us a deeper understanding of the tension between competitiveness and cooperation, the most common example of which is the “Prisoner’s Dilemma,” first developed in the 1950s by the Rand Corporation to model global nuclear strategy. The scenario is that each of two prisoners arrested for a crime is independently made an offer (and both know the other has been presented with the same deal). To make the game more real, pretend you are one of those charged with the crime. Here are the four possible options:

  1. If you and your partner cooperate with each other and take the Fifth, then you each get one year in jail.

  2. If you confess and admit that your partner was in on the crime with you, then you get off and your partner gets three years in the slammer.

  3. If your partner confesses and you don’t, then you receive a three-year stay in the pokey while he walks.

  4. If you both confess, then you each get a two-year stay in the gray-bar hotel.

  What should you do? If you
defect on your partner and confess, then you will get either zero or two years in the pen, depending on what he does. If you cooperate and stay quiet, you get either one or three years, again depending on his response. In this scenario the logical choice is to defect. Of course, your partner is likely going to make the same calculation as you, which means he too will defect, guaranteeing that you will receive a two-year stint in prison. Knowing that he is probably computing the same strategy as you, then surely he will realize that you should both cooperate. Of course, perhaps he’ll figure that this will be your conclusion as well, so he’ll defect in hopes that you will cooperate, getting him off the hook and sending you to wallow in the general population for three big ones. Herein lies the dilemma.

  When the game is noniterated—that is, just one round is played—defection is the norm. When the game is iterated over a fixed number of trials, defection is also the norm because awareness of how many rounds there will be means that both players know that the other one will defect on the last round, which pushes another defection strategy to the second to the last round, and so forth back to the start of the game. But when the game is iterated over an unknown number of trials, and both players keep track of what the other has been doing throughout the history of the game—that is, it more closely resembles real life—cooperation prevails.