THE HANDICAP PRINCIPLE, THE TEN COMMANDMENTS, AND OTHER MECHANISMS FOR ENSURING COLLECTIVE SURVIVAL
THE MOST WIDELY ACCEPTED MODEL OF EVOLUTION HAS AT ITS CORE two main elements: mutation and selection. Mutation causes random changes in the characteristics of organisms from one generation to another. Selection is the mechanism by which “good” mutations spread in a population while “bad” mutations slowly die out. Individuals who possess good characteristics are better at surviving than those who lack them, ensuring that they have more offspring.
We usually think of evolutionary forces as shaping the characteristics of individuals (or genes), but mutation and selection also influence the evolution of societies. Societies with positive characteristics (such as social structures and values that preserve cohesion) will survive better than societies that lack them. The latter will be defeated in battle more often and will be abandoned more often by individuals.
Researchers in biology and social science are increasingly using models of group evolution to understand social structures among animals and humans. The two main evolutionary models that have been developed in this field are called group selection and kin selection. These models differ in much more than name alone: using one instead of the other can sometimes lead to completely opposite conclusions.
Take, for example, the question of whether or not humans may one day attain a life expectancy of 1,000 years. According to the kin selection model, this is eminently possible. Mutation will bring about random genetic changes that over time will grant humans immunity to virtually every known disease. Those lacking the life-extending genetic mutation will die out, leaving only individuals with a 1,000-year life span.
From the perspective of the group selection model this sort of development is inconceivable. Societies composed of people with 1,000-year life spans will fail to benefit from generational change and become developmentally “frozen.”
They will suffer from perpetual resource constraints as their population levels skyrocket, leading to wars that will kill off many more people than in societies like ours, in which life expectancy is only 80 years.
Researchers have heatedly debated the legitimacy of the group selection model. Critics claim that thinking of societies or groups as autonomous individuals is fundamentally wrong. In this view, only individual animals (or human beings), along with their genetic compositions, can be conceived of as individuals subject to evolutionary pressures.
I find this approach too rigid. The “what counts as an individual” question is a philosophical one that has no single unequivocal answer. Consider examples such as ant colonies or corals, where what should be regarded as the “individual” level is far from immediately clear. In many cases an entire ant colony can be studied as an individual more usefully than if it is regarded as a collective formed from individual ants. The same reasoning applies to corals as a whole versus their constituent polyps.
In fact, one can think of a single human being as a colony composed of the individual cells in his or her body. This approach is increasingly being adopted in medical studies. There are articles in scientific journals analyzing competition taking place between cells in living creatures using game theoretical models that have successfully explained various pathological phenomena, including cancerous growths.
The subject of altruism is one of the more perturbing questions being studied by social scientists (including economists) and biologists. The kin selection model can explain why an individual might sacrifice himself for the sake of a family relation (such as a sibling or an offspring). Altruism of this sort can survive and spread in a population because the survival of family relations is in effect the survival of genes, given that family members share a similar genetic pool. The survival of genes is equivalent to the survival of behavioral characteristics.
But how can true altruistic phenomena, in which individuals help other individuals with whom they share no genetic heritage, be explained? The moral principal of aiding others (even if they are not family members) is nearly universal. It can be found in all cultures and religions. What advantage is there to individuals in wanting to help others and exhibiting broad solidarity? The psychological reward from the satisfaction of helping others cannot be sufficient to explain this. This positive sensation is a symptom of the fact that giving contributes to individual survival, just as the pleasure we take from eating sweet chocolate is a symptom of the fact that sugar (in proper moderation) is necessary for our survival. But in both cases the sense of satisfaction is not an explanation.
The desire to help others (even if they are not family relations) exists in other animals, not just in humans. The story of the Battle at Kruger described in the previous chapter is an excellent real-life example. The Arabian babbler, a bird native to desert areas in the Middle East, provides us with another. Babbler flocks have very complex social structures. They live in “communes,” with collective sleeping areas in which the adults share in the burden of raising all the chicks of the flock. They assist each other in incubating eggs, seeking food for the chicks, and providing for the common defense of the entire flock’s brood of chicks. Each adult bird is, in effect, investing heavily in providing for the flock at the expense of providing for his or her direct offspring. Could all this possibly exist simply because of the psychological boost that babblers get from helping others?
The kin selection model and the group selection model can both provide evolutionary explanations for the emergence of the behavioral trait of helping others. Both humans and babblers receive a personal reward in the form of increased chances of survival as a result of helping others. Altruism in societies promotes reciprocity. There is no room for freeloaders in societies that exhibit a preference for reciprocity (in addition to a desire to help others). Individuals who lack the desire to help others are punished by social ostracism that harms their prospects for survival. In contrast, those who give are usually rewarded by receiving the support of others.
Research conducted with the use of fMRI shows that the brain reacts to social ostracism in the same locations and to the same extent that it reacts to disease and the threat of severe danger. In other words, social ostracism and existential threats lead to the same distress reaction.
Of course, there are also differences between human societies and babbler flocks. A babbler bird who invests all his energy solely in providing for his chicks will not be helped by the other birds, and risks being physically chased out of the flock. The communal living structure of the babblers and the close cooperation that takes place between them enable close and efficient monitoring of the behavior of each individual.
Human societies, on the other hand, are less collective and much more individualistic. Thus it is difficult for humans to monitor the altruistic behavior of the peers, whereas babblers do so relatively easily and comprehensively. This can weaken the advantage of altruistic giving among humans.
There have been attempts to create human societies that are communal to the same extent as those of the babblers. Such communes proliferated in the United States in the “hippie” culture of the 1960s. Kibbutz collectives in Israel included communal sleeping quarters for children well into the 1990s. The general record of failure of human communes to sustain themselves over time indicates that babbler-style living arrangements are not natural for humans.
Another example of altruism among birds can be found in the behavior of starlings. In contrast to the babblers, starlings jealously protect their mates and offspring. They do not care for the chicks of other starlings, and they react aggressively to any attempt by rivals to steal their mates. But starlings behave with impressive bravery when it comes to external threats. If a predator approaches a flock of starlings, the first bird who notices this will emit loud cries in order to warn the other members of the flock. Doing so is not only a waste of energy from the selfish perspective of the individual who has volunteered to warn the others, it actually increases his personal danger by drawing the attention of the predator.
Zoologists place this sort of altruism in a different category from the altruism exhibited by babblers. The behavior of the starlings is related to the “handicap principle,” first proposed by the biologist Amotz Zahavi.1 The handicap principle posits that animals (especially males) will handicap themselves or place themselves in apparently dangerous situations to signal potential mates that they have genetic advantages, thus improving their prospects for mating successfully, outcompeting their rivals. Zahavi originally suggested the handicap principle as an explanation for the evolutionary development of the peacock’s tail. Peacocks have extraordinarily impressive tails. Those tails, however, are also extremely heavy while providing in return no physical advantage in the peacock’s natural habitat; in fact, the tails are so burdensome that they are disadvantageous.
The understanding that peacocks’ tails are actually handicaps naturally led zoologists to ask why evolution hadn’t long ago eliminated them. Zahavi’s answer to this question was brilliant and original: the advantage of the peacock’s tail, suggested Zahavi, is precisely that it is a handicap. Having such a long tail is not a luxury that every peacock can afford. Only the strongest, healthiest, and smartest peacocks can have efficient and easy mobility despite the limitations incurred by carrying a heavy tail. A large tail is in fact a signal indicating strength, health, and intelligence, attracting peahens seeking strong, healthy, and intelligent mates who will pass those genes on to their offspring and thus increase their prospects for survival. A peacock with a very long and heavy tail is rewarded with a steamy love life with several peahens while passing on genes that increase his chicks’ chances of survival. The male offspring of such a peacock will, of course, also have long and heavy tails.
My colleague Yair Tauman has made use of the handicap principle in his research to explain the tendency of founders of high-tech start-ups to drop out of college before completing their degrees, even when they are very close to the end of their studies;2 Microsoft founder Bill Gates and Facebook founder Mark Zuckerberg, both of whom dropped out of Harvard, are only two of the most prominent examples. In Tauman’s model, such people, who are well aware of their own talents, find it advantageous to drop out because this “handicaps” them in a way that sends a positive signal to potential investors. In effect, they are saying that they believe in themselves and their ideas to such an extent that they are willing to forgo the job market advantage conferred by an academic degree.
The handicap principle also explains the altruism exhibited by starlings. Starlings do not strut around showing off useless tails, but they do show off by loudly helping their flocks avoid predators. The closer a starling allows himself to get to a predator and the louder he emits a warning call, the better off he is in signaling that he has advantageous genes, thus increasing his chances of impressing potential mates.
In this regard, humans are no different from starlings. A few years ago my nephew Ro’i volunteered to serve in an elite military unit with very selective entry requirements. He and his friends from the unit wanted to celebrate their completion of the unit’s very stringent and demanding training course by holding a large party in a club in Tel Aviv, and they went from club to club to bargain the best possible price for reserving a place for a night of partying. They certainly managed to get a good deal—one of the largest and most luxurious clubs in the city offered not only to let them hold the party on its premises for free, it also gave each soldier in the unit a valuable gift. All it asked in exchange was for the soldiers to agree to let the public join in their party for a fee. The club made a great deal of money that evening from the entrance fees it collected. Hundreds of young women came to the party in the hopes of meeting a brave and strong young man in an elite military unit. The presence of so many women attracted an equal number of young men.
One might make the claim that both starlings and humans, such as soldiers volunteering for dangerous military units, do not exhibit true altruism because they know exactly what they will receive in return while true altruism involves giving without expectation of receiving anything in return. In fact there are biologists who claim that pure altruism does not exist and cannot possibly exist in nature, on the grounds that any behavior that confers no advantage to the individual performing it will eventually go extinct through natural selection. Obsessive altruists, individuals who give and only give (and there are people like that) cannot survive from the evolutionary perspective because they will come to the aid of others in dangerous circumstances but refuse to accept aid for themselves.
There is, however, an evolutionary explanation at the genetic level that can justify pure giving in social groups with very little genetic heterogeneity. In such groups, granting assistance to another member of the group is similar to helping a daughter or a brother. Helping another individual in a genetically homogenous population to survive, under this theory, is like helping yourself survive, because in effect you are helping your own genetic inheritance to survive and spread. Researchers debate whether this explanation is applicable to the sort of altruism exhibited by starlings, but it is widely accepted as explaining the behavior of social insects, such as ants and bees, who long ago lost the capacity for individual reproduction and instead loyally serve their queens. Altruism and giving, it should be noted, are more prevalent among humans in ethnically homogenous societies.
About a year ago I was invited to visit the University of Oslo in Norway. The Norwegian government had invested a large sum of money in a research study focused on a comprehensive comparison between the Scandinavian economic system and the more free-market oriented systems that are prevalent in other developed countries. This research effort was not entirely politically neutral. I got the impression that the Norwegian government was trying to justify the advantages of the egalitarian Scandinavian system to itself, its citizens, and the rest of the world.
In all honesty, anyone who has ever visited Norway or Sweden will find it very difficult to argue against the Scandinavian approach. The Scandinavian countries are blessed with strong economies, excellent health and education systems that are available for free to all citizens, and virtually no poverty or crime. Taxation levels in Scandinavia are among the highest in the world, yet tax evasion is completely negligible.
When asked for my opinion, I said that what needs to be studied is whether the extraordinary success of the Scandinavian system is a result of the system itself or of the public that chose this system. It would be very difficult, I claimed, to transplant the Scandinavian system to other countries. The Scandinavian nations are much more homogeneous than most Western nations, whether the homogeneity is measured ethnically or culturally. They developed historically from small Viking tribes with traditions of egalitarian sharing, tribes that over time grew to the size of nations.
Countries (such as the United States) that have to contend with much more ethnic and cultural heterogeneity will find it difficult to adopt a Scandinavian-style economic system because doing so would involve a significant amount of cross-ethnic and cross-cultural giving. Research recently conducted by the National Bureau of Economic Research in the United States studied patterns of community charitable giving in American neighborhoods. Ethnic diversity in a neighborhood was correlated with small amounts of community charitable giving. A 10 percent increase in ethnic diversity in a neighborhood is associated with an average drop of 14 percent in community charitable giving.3
The genetic-level evolutionary explanation of the spread of altruistic giving in populations is based on three elements. The first is deterrence: an individual lacking any sense of solidarity or desire to come to the aid of others will be ostracized from social interactions and thus pay a very high personal price for such behavior. In early human nomadic hunter-gatherer societies that price was equivalent to a death sentence. A successful hunt requires close cooperation among a band of hunters. A man in hunter-gatherer societies who failed to cooperate on hunts or refused to share with others would very quickly find himself starving to death with little prospects of reproducing. Those behavioral traits would thus die out.
The second element is the handicap principle. The very act of conspicuous giving increases an individual’s chances of reproducing. The third element is the fact that in genetically homogeneous environments, giving to others serves the interests of propagating the altruist’s genes.
The group selection model provides us with a smooth, direct, and simple explanation for the evolutionary survival of altruistic behavior. This model posits that mutation and selection operate at the group level, as opposed to the individual (or the genetic level). Groups that fail to place moral value on mutual assistance will go extinct faster than competing groups.
Imagine a battle between two tribes for control of vital natural resources. One tribe maintains a strong moral imperative for mutual aid among its members, while the other tribe believes that each individual should look out only for himself. It is not difficult to predict the outcome of the battle. Keep in mind, however, that even at the group level there has to be some amount of moderation for the principle of altruism to be beneficial. A tribe whose moral code calls on each individual to sacrifice him or herself for the sake of others in every possible situation will go extinct faster than a competing tribe embracing a less sweeping code of altruism.
This is one reason that religion has been such a powerful force in human history: it creates a social cohesion that benefits the collective of its adherents. The Ten Commandments are a fine illustration of this principle, having helped ensure the survival of the relatively small world population of Jews, and later the survival of much larger communities of Christians and Muslims. Not coincidentally, almost all of the content of the Ten Commandments have been adopted widely throughout the world in the form of religious or social precepts.
At their heart, the Ten Commandments operate based on three mechanisms: (1) ensuring the physical existence of the group, along with its social cohesion; (2) incentivizing reproduction; and (3) providing disincentives to leaving the group.
The first three commandments are there to ensure the primacy of this ethical code above all others. Of course, populations that take their code more seriously are more likely to follow it, and thus to survive. The next seven create a social contract, enforcing prohibitions on theft, adultery, and murder, as well as creating mutually beneficial relationships between family members and neighbors.
The importance of many of these commandments to the well-being of a community is self-evident. But there are a few that bear further analysis. The fourth commandment, “Remember the Sabbath day to keep it holy,” has an important role in preserving the group. The Sabbath day is a day of rest during which an individual’s main attention is focused not on him or herself but on the collective; it thus preserves group cohesion. The commandment explicitly relates to the “other”: “your son, your daughter, your servant, your livestock, and the sojourner who is within your gates.” This commandment also encourages economic relations within the group, reducing the danger of individuals abandoning it to join other groups. An employee from within the group will seek an employer from the group, who observes the Sabbath rest and grants the employee the same day of rest. That employee will similarly find it difficult to work for someone who is not a Sabbath observant and therefore may expect him to work on the Sabbath. This creates mutual dependencies within the community, reducing the chances that people will leave the group.
The fifth commandment, “Honor your father and your mother,” stands out among these commandments. It is the only one that promises a reward, “that your days may be long,” to those who follow it. This creates a very clever social mechanism—an intergenerational contract—that functions as a strong incentive to have children.
At first glance it may be unclear how honoring one’s father and mother serves the goal of group survival, and why such a tempting reward as long life should be offered for those who keep this commandment. Elderly mothers and fathers require honor and assistance long after their fertility has waned. From a purely evolutionary perspective you should perhaps invest time and effort exclusively in your children, not your parents, for the sake of both your genetic survival and the survival of the group. You might even be tempted to think that ignoring your parents and leaving them to fend on their own would be more beneficial for the group than helping them, because elderly parents consume precious and limited resources while contributing almost nothing to the group in return. They cannot protect the existing generation, and they do not create new generations.
But this line of thinking turns out to be wrong. An ethical code permitting hostility or even indifference to elderly parents creates a disincentive to having children, threatening the group with extinction. The true meaning of the reward “that your days may be long” then becomes almost self-evident: honor your father and your mother so that your children will in turn honor you when you become elderly. This intergenerational contract is amazingly similar to a pension scheme. When we urge our adult children to keep visiting their grandparents and inquire about their well-being, we are, even if subconsciously, reminding them that the intergenerational contract also applies to us. In summary, the fifth commandment is not only a way of ensuring that parents are cared for, it also provides an incentive to have children, without which the group cannot continue to survive.
The Bible and Talmud contain many more rules and regulations, over and above the Ten Commandments, intended to preserve group cohesion and stability. These were especially necessary for a dispersed people such as the Jews, who lacked a national territory of their own and faced many incentives to leave the group and join instead the broader cultures in which they were located.
The rules dictating kosher food are an interesting example of this. Many believe that they were intended simply to protect people from unhygienic food sources, but their true aim was preserving group cohesion. In virtually every culture and every era, dining was considered an important social activity that was conducted in a group setting. The kosher food rules greatly limit opportunities of Jews and non-Jews dining together, thus limiting social interactions between Jews and non-Jews in general. This by itself reduces substantially the chances of coming into contact with incentives to leave the group. Completely forbidding common dining between Jews and non-Jews might have created unwanted antagonisms. The construction of a complex set of seemingly arbitrary rules limiting which foods may be eaten succeeds in limiting contact in a more subtle way.
The above analysis is based on the group selection model of evolution. But every evolutionary model (including those operating at the level of groups rather than individuals) requires mutation in addition to selection. In the group selection model, the role of mutations is in ensuring that the group does not remain forever static in its norms and behaviors.
This is especially important under changing environments. Liberal societies that are tolerant of minorities, public protests, eccentric behavior, and free expression of ideas, enable mutations to contribute positively. They facilitate the adaptation of the group to its changing environment. Many of the most important social changes in human history started out as anomalous behavior relative to social norms. Fundamentalist societies that aggressively crush every attempt to introduce change block social mutations from taking effect. They lose their ability to adapt their norms and values to changing environments, greatly reducing their chances of surviving social genetic competition.