Behave: The Biology of Humans at Our Best and Worst

The final chapter of Sapolsky’s book is one of the longest, presenting evidence that the worst of human behaviors are becoming less prevalent in society while our best ones are ascendant. Throughout the chapter, he highlights how several factors of brain biology he has already covered, including learning-to-automaticity, reappraisals of Us/Them relationships, empathy and cultural conditioning, can lead individuals to become their best. Like the chapters before, this is a massive application of all the science of behavior we have previously seen to a major social issue.

In the year 1800, slavery, child labor, and animal abuse were legal across the globe. Renaissance Europe averaged 41 homicides per 100,000 people per year. Today, it’s 1.4 (though some global nations of today exceed Renaissance rates). Sapolsky lists several more horrors of the past currently declining—“persecution of homosexuals […] beating of schoolchildren […] death in childbirth […]” and several more recent moral inventions, such as “the concept of crimes against humanity […] agreements to hinder trafficking of blood diamonds […] industries that battle global pandemics and send medical personnel to any place of conflict” (615). Sapolsky also recognizes such rules are not universally enforced, and humans across the globe can still do quite horrific things to each other. “Nonetheless, worldwide, things have improved” (615).

Sapolsky now brings up a book he previously cited heavily in Chapter 9: Steven Pinker’s The Better Angels of Our Nature. Sapolsky agrees with Pinker’s argument that “organized human violence predates civilization, stretching back to our last common ancestor with chimps” (616), and therefore it is no surprise that horrific violence occurs throughout the world’s cultures and human history. Sapolsky then reviews Pinker’s argument of why such events are in decline, which is that it is a result of the “civilizing process” (617) that accompanied the Enlightenment and modern state formation. Arguably, however, such “giddy overvaluing of the dead-white-male Enlightenment fuels Western neoimperialism” (618). This is a counter-argument launched by some anthropologists, which they support with evidence that in some cases violence is in fact less frequent in traditional culture. Sapolsky’s argument that violence predates civilization should not be understood as support for a colonial agenda. Instead, it should be understood as evidence that the violence of all cultures emerges from our human natures, which are the true substrate structuring society. In fact, the idea that human morality is extended via conditions of the scale of state and culture (the basic argument of the civilizing process) exemplifies how any culture could be capable of such enlightened advances given the proper variables.

Although the world is getting more peaceful overall, globalization and instantaneous worldwide communication also extends the reach and influence of the “violent few” (619). Even if we are less violent today, our potential for violence is greater than ever. What strategies help to reduce violence? Migration to escape violence is a common historical trend. Stable trade relationships between nations as well as cultural diffusion also decrease the likelihood these nations will fight each other: “Where goods do not pass frontiers, armies will” (620). This is an example of the civilizing process at work.

Religion is a new topic of study in the science of morality. All the world’s religions make stipulations for both personal and collective behavior with their effects on prosociality largely being limited to group members. For insiders, religion promotes charity, trust, and forgiveness. For outsiders, it justifies atrocity, dehumanization, holy war. Religious war also tends to be more tenacious and long-lasting than wars without sacred justifications. However, it is not religiosity alone that predicts violence. However, the more you regularly attend church, mosque, or temple, the more likely you are to support violence against those of other religions. “It’s not religiosity that stokes intergroup hostility; it’s being surrounded by coreligionists to affirm parochial identity, commitment, and shared loves and hatreds” (626). In other words, to apply findings of a previous chapter: Religion is one of the strongest ways humans create Us/Them relationships. Religious values of love and equity are examples of the sentiments we extend to members of our in-group, the Us. Religion’s justification of war is an example of the sentiment we extend toward the out-group, the Them. To pick up on another chapter, religion codifies these ideas through metaphor and enshrines them in sacred values. This makes religious ideas very resilient. If we structure these values correctly, it can also make religion a very potent tool for social good.

Chapter 11’s coverage of contact theory showed that consistent intergroup contact decreases hostility, given specific conditions. Though these conditions are many, one key takeaway comes out: It is infinitely harder to treat others with violence or hatred when we are encouraged to recognize them as human. Sapolsky illustrates this with a narrative of the Black South-African clinical psychologist Pumla Gobodo-Madikizela’s memoir of her time spent interviewing Eugene De Kock, a counter-insurgency commander responsible for many murders, and her growing pity and empathy for the man as she understood more and more of his emotional world (629-30).

What does this tell us of conflict? One of the strongest tools to brainwash someone toward group dedication is to have them burn cultural bridges. Child soldiers are often forced to kill their own family members as initiation into armies, as they are told, “We are your family now” (630). Furthermore, as covered in Chapters 11 and 15, we must beware of any leader who uses dehumanizing rhetoric of our antagonists as well as those who play on our empathic intuitions or moral virtues by citing the moral crimes of our antagonists. Such awareness of the value of seeing others as part of our group to enhance common good or awareness of the tools genocidal maniacs will use to convince you of the correctness of their horrible acts are examples of how scientific understanding of human nature gives us tools to enhance our lives and the world.

Why do humans cooperate with strangers? The answer could be that real world economic games are examples of open-ended play: We never know if we will see our play partner again, which encourages cooperation in case we need them later. This explanation would coincide with the argument of the civilizing process: We have gotten better to each other over time because we have recognized that everyone, even people in nations far away from us, are our trading partners. To take it a level deeper, this is based on the science of reciprocal altruism: I am good to you because I expect that if I am, you will be good to me. This only works when we are in contact with each other.

Though the basics of reconciliation for wrongs are evident in primate species, humans are the only species that institutionalizes reconciliation, such as in the Truth and Reconciliation Commissions (TRCs), which have cropped up in several nations in the modern era. Notably, these commissions often do not require remorse and forgiveness so much as they are focused on “increas[ing] the odds the shattered nation[s] would function” (639) by focusing on reparation and judicious applications of amnesty. In other words, reconciliation does not need to mean forgiveness.

Further, forgiveness is not forgetting, even neurobiologically speaking. If a rat is conditioned to associate a sound with a shock, this association can be extinguished by repeated events decoupling the sound from the shock, but once the sound and shock are reassociated reacquisition of the association is faster than initial learning. To bring back reasoning from the previous chapters, this is an example of the function of neural plasticity via long term potentiation (LTP). The neural connections between the shock stimulus and the reaction have strengthened and can be relearned faster. For humans, forgiveness usually requires reappraisal. A statement such as “I forgive for myself, not for you,” or a recognition that you and the person you are harmed by are both victims of an overarching circumstance can transform a Me/You relationship into an Us.

In general, people are highly averse to killing. Surprising statistics back up this fact. Of the 27,000 muskets recovered from the Battle of Gettysburg, 24,000 were left unfired. In WWII, only 15% to 20% of riflemen ever fired their gun. We are most averse to close combat killing (with hands or knives), somewhat less to medium range (guns), and least to long range (bombs, artillery). Killing in a group is also easier, as killing in a group dilutes responsibility.

Notably, drone pilots—who in fact kill quite intimately, often watching their targets for weeks—have just as high rates of PTSD as infantry. Although we used to believe PTSD came from the terror of being attacked, it is likely often due to the even deeper trauma of killing. As militaries train killing to be more reflexive via virtual reality human targets, soldiers’ aversion to killing is declining.

How do we use the information we have marshalled to forward a study of the potential for peace? Sapolsky starts with a story of a baboon troop he studied who took to foraging on the garbage of a nearby tourist lodge. As these baboons grew fatter, aggressive males from a neighboring troop began to visit and compete for the scraps. Then, a tuberculosis outbreak, which kills baboons within weeks, spread across the troop. This killed the aggressive males of the neighboring troop who visited the dump, leaving that troop with a 2:1 female male ratio and with all surviving males particularly unaggressive and affiliative. This brought about a highly non-aggressive culture unique to this troop, which was then adopted by new males as they entered the group. This occurred because the females, in a state of non-stress due to the lack of need to fend off aggressive male advances, were more willing to risk affiliative overtures to new individuals, which assisted in an assimilation of aggressive adolescent males into the non-aggressive culture. This teaches us that our aggression is not innate. Instead, our behavior is plastic and peace only requires a culture of peace. Another way to think about this is to recognize the importance of social learning in primates. Because we are so social, and because we have such high cognitive function, humans are better than any other species at social learning, and the vastness of our behavioral repertoire—far greater than any other species—represents this. Therefore, to improve our behavior, we must teach good behavior within our cultures. Because we learn most of our sociality in adolescence, our parents need to be the primary teachers of this behavior.

Singular acts of individuals often catalyze great reforms. Gandhi and Mandela are clear examples. The 26-year-old fruit seller Mohamed Bouazizi, who immolated himself in front of a government office after being beaten for being unable to pay a bribe, which incited much of the action connected with the Arab Spring, is a somewhat less known example.

Another example involves the My Lai massacre. During the Vietnam war, a company of 100 American soldiers massacred a Vietnamese village, killing the elderly and infants and raping the women. Reports from the atrocity indicate individual thresholds for killing varied, with some refusing orders even under threat of court martial. One soldier, the helicopter pilot Hugh Thompson, who was flying over and realized what was occurring and showed incredible bravery in landing his helicopter between a group of soldiers and civilians, threatened to kill fellow Americans unless they ceased their attack. This is a dramatic Us/Them recategorization.

These are acts of incredible selflessness and bravery. However, as Sapolsky’s coverage of a former slave ship captain who renounced slavery as an elderly man (659-61) and became one of the great voices of the abolitionist movement indicates, even gradual change based on slow cognitive reappraisal can be effective, provided we eventually do make it.

Another example of unlikely peace is the frequent fraternizing that occurs between opposing soldiers in war, which is more common if they’re of the same race, religion, or lower rank and when they encounter each other as individuals often. A famous example is the Christmas truce of 1914, when German and English soldiers in World War I made an agreement to halt hostilities during Christmas dinner, began exchanging food, helping each other dig graves, and eventually started playing soccer together. “For most of the 500 miles of trenches, the truth held through Christmas, and often even New Year’s. It took officers' threats of court martial to get everyone back to fighting” (664).

This truce likely worked due to the proximity of trench warfare, the threat of revenge for those against it, the ethnic proximity of the two fighting groups, their mutual animosity to the other’s allies (e.g., the French were British allies but long-time cultural antagonists), and the top-down authorization from the Pope and God that this was a holy day. Other truces of infantrymen existed throughout the war, upheld by fear of reciprocal action (no one shot food carts) or via ritualized signals—a sniper repeatedly shooting the same empty spot on a wall and the other side’s sniper returning the gesture to signal shots would be aimed over each other’s heads. Furthermore, a Tit for Tat system emerged for truce breaking: fire a shell at us, we fire two back at you, then the truce resumes. This is another example of the functions of reciprocal altruism in the real world. These cultures of non-hostility produced a sense of camaraderie unique to the trench combatants who stood against the dehumanizing rhetoric forced on troops by war propaganda. Thems became not the military enemy but shared enemies of rats, lice, death, and officers with no regard for the lives of their troops. This shows us the most important way for us to improve social relations between groups is to help them reappraise themselves as essentially the same and recontextualize the Them status onto another group. Even more importantly, because of our capacity for metaphorical thought, this Them does not even have to be another human group but can be concepts we are taught to abhor.

Today, such events of truce with adversaries such as Al Qaeda seem unlikely. However, such was true of Japanese-American hostility in WWII as well. How likely are we in the future to “look back at our current hatreds and find the mysterious” (668)? If we are to remember how to restructure Us/Thems into Uses (like Japan and America have now done, engaging in free trade between the two nations) it is undoubted that our world will continue to be a better place.

In this chapter, Sapolsky focuses on how reshaping Us/Them relationships can be a powerful tool toward moving away from what we may think of as an absolute human constant, war. In this discussion, this chapter shares its core argumentative features with the chapters prior. Chapters 12 to 17 have worked to show how the macro conditions of society (the prevalence of war, nations, or certain concepts in criminal justice) are not primarily based on emergence from the social systems we put in place. While in some cases our social systems do change how we behave—such as through the civilizing process or the more general effects of culture on behavior—these are not the primary factor. Instead, the primary factor in our global social systems is our biology—the way our worlds work is a function of how we work as an organism. Therefore, ultimately understanding society and being able to effectively shape it, relies on understanding ourselves as a species.