Behave: The Biology of Humans at Our Best and Worst

“Here are some words of central importance to this book: aggression, violence, compassion, empathy, sympathy, competition, cooperation, altruism, envy, schadenfreude, spite, forgiveness, reconciliation, revenge, reciprocity […] flinging us into definition of quagmires. Why the difficulty? […] One reason is that so many of these terms are the subject of ideological battles over the appropriation and distortion of their meanings […] These terms mean different things to scientists living inside different disciplines.”

Working categorically in science provides concision and comprehensibility, which is necessary to the correlative nature of the scientific process. However, this process does little to offer us modes of deciphering the real-world complexity of emotion and behavior. Definition only provides categories. A holistic approach that goes beyond any one discipline is necessary, and the project of this book.

“The opposite of love is not hate; its opposite is indifference.”

These words are Freud’s, reiterated by the Nobel laureate and Holocaust survivor Elie Wiesel. It illustrates a point that Sapolsky will reiterate again and again throughout this book, which is that biologically a behavior we deem morally laudable and morally reprehensible can be identical: our sympathetic nervous system may activate, stimulating an aggressive response to kill our spouse or protect them from an attack. It is only in context that these behaviors can be differentiated. The real opposite to an act of love or an act of hate is not another act but a state of non-action.

“Various muscles have moved, and behavior has happened. Perhaps it is a good act: you’ve empathically touched the arm of the suffering person. Perhaps it is a foul act: you’ve pulled the trigger targeting an innocent person. Perhaps it is a good act: you’ve pulled the trigger and drawn fire to save others. Perhaps it is a foul act: you’ve touched the arm of someone, starting a chain of libidinal events that betray a loved one. Acts that, as emphasized, are definable only by context.”

To illustrate the irreducible necessity of viewing behavior in its context, Sapolsky treats a single behavior as it could be categorically defined: movements of muscles in the fingers. As the quote explicates, these behaviors could cause exactly the same immediate physical events, the firing of a gun or the touching of an arm. However, both the gunfire and the touch can be incredibly malevolent or incredibly altruistic, whether they are superficially aggressive or kind.

“Logically, when the amygdala wants to mobilize a behavior—say, fleeing—it talks to the frontal cortex, seeking its executive approval. But if sufficiently aroused, the amygdala talks directly to subcortical, reflexive motor pathways. Again, there’s a trade-off—increased speed by bypassing the cortex, but decreased accuracy. Thus the input shortcut may prompt you to see the cell phone as a gun. And the output shortcut may prompt you to pull a trigger before you consciously mean to.”

Sapolsky shows how relevant understanding the nuanced functions of neurobiology is to understanding the complexity of human action. Referencing the shooting of Stephon Clark when a police officer mistook his phone for a gun, Sapolsky diagnoses this event not as a simple event of racial injustice but as at least in part due to the complexity of neural wiring emerging from an evolutionary past no longer suited to our social lives, a neurological mistake. As future chapters will outline, however, cultural control against this sort of behavior—a culture which, for instance, works against seeing other races as others—can improve our suppression of such impulsive acts.

“Once we had lives that, amid considerable privation, also offered numerous subtle, hard-won pleasures. And now we have drugs that cause spasms of pleasure and dopamine release a thousandfold higher than anything stimulated in our old drug-free world. An emptiness comes from this combination of over-the-top non-natural sources of reward and the inevitability of habituation; this is because unnaturally strong explosions of synthetic experience and sensation and pleasure evoke unnaturally strong degrees of habituation […] If we were designed by engineers, as we consumed more, we’d desire less. But our frequent human tragedy is that the more we consume, the hungrier we get.”

Closing a section discussing the function of the dopaminergic system in inspiring us toward reward-seeking, Sapolsky describes another tragedy emerging from the fact that our brains are not designed for the world we currently live in. Our constant cycle of craving reward and becoming habituated to its standard levels, unless understood and put in check, can doom us to living life consistently chasing a prize forever exceeding our grasp.

“There’s been a proliferation of ‘neuro’ fields. Some, like neuroendocrinology and neuroimmunology, are stodgy old institutions by now. Others are relatively new—neuroeconomics, neuromarketing, neuroethics, and, I kid you not, neuroliterature and neuroexistentialism. In other words, a hegemonic neuroscientist might conclude that their field explains everything. And with that comes the danger […] that explaining everything leads to forgiving everything. […] It is wrong to think that understanding must lead to forgiveness, mainly because I think a term like ‘forgiveness,’ and others related to criminal justice […] are incompatible with science and should be discarded.”

In a down-to-earth and humorous note, Sapolsky pokes fun at his own field’s habit of thinking it can perform as a metanarrative: one story that explains and accounts for everything. Neuroscience, though it can lead us to a much deeper understanding of why we are the way we are, neither explains away the richness and irreducibility of what it is to be alive nor excuse behaviors that, though they have a neurological basis, are unacceptable among moral beings. Neuroscience should be dedicated only to the impartial analysis of the biological mechanisms underlying behavior, not any value judgements on them.

“No brain operates in a vacuum, and over the course of seconds to minutes, the wealth of information streaming into the brain influences the likelihood of pro- or antisocial acts. As we’ve seen […] much of these varied types of information is subliminal. Ultimately […] in the moments just before we decide upon some of our most consequential acts, we are less rational and autonomous decision makers than we like to think.”

Closing his chapter on the modulating effects that an immediately preceding stimulus can have on a behavior, Sapolsky reminds us of two facts. First, much of what we do is based on automatic reflexes programmed not by rationality in our modern world but by their likelihood to keep you alive in an evolutionary environment long past. Second, neuroscience is a tool to help us understand and adapt to how automatic and out of our conscious control our actions can really be.

“Over the course of minutes to hours, hormonal effects are predominantly contingent and facilitative. Hormones don’t determine, command, cause, or invent behaviors. Instead they make us more sensitive to the social triggers of emotionally laden behaviors and exaggerate our pre-existing tendencies in those domains.”

Hormones are often viewed as chemicals with causal effects. If you take anabolic steroids, you grow your muscles; if you take estrogen or testosterone, you become more feminine and emotional or masculine and aggressive. This is an incorrect picture of hormones. Hormones dispose us toward certain behaviors based on context. Testosterone may make us aggressive in societies that favor aggression as a mode of mate selection, but can also make us more affiliative if our society favors this behavior to attract mates.

“Altman, who at the time of this writing is 89, published a 2011 memoir chapter. Parts of it have a plaintive, confused tone—everyone was so excited at first; what happened? Maybe he spends too much time in the lab and two little marketing the discovery, he suggests […] He’s philosophical about it—hey, I’m a Hungarian Jew who escaped from a Nazi camp; you take things in stride after that.”

Sapolsky describes the memoir of Joseph Altman, who was pushed out of academia after discovering adult neurogenesis and being rejected by his more well-situated peers who believed all neurogenesis occurred in the womb. Characteristically wry, Sapolsky gives us an insight into the personal, emotional, and counter-factual aspects of science as it is actually practiced in human culture. The passage forms a sort of meta-comment on the book: Even those of us who are supposed to be the most impartial, even those of us who actually study this very thing, are capable of the thoughtless, self-aggrandizing action that characterizes so much of human behavior. These geniuses are also subject to biology driving us, sometimes, to behave at our worst.

“Take baboons. Suppose two troops encounter each other at some natural boundary—say, a stream. The males threaten each other for a while, eventually get bored, and resume whatever they were doing. Except there’s an adolescent, standing at the streams edge, riveted. New baboons, a whole bunch of them! He runs five steps toward him, runs back four, nervous, agitated. He gingerly crosses and sits on the other bank, scampering back should any new baboon glance at him.”

As well as a world-class endocrinologist, Robert Sapolsky is also a primatologist and spent decades observing the behavior of baboons. Here, we receive a brief insight into Sapolsky’s other main academic field. We also get a picture of the essential similarities between our own behavior in adolescence and that of other primates based on two traits adaptive to adolescent success: high affiliative behavior, and high risk-taking.

“A first challenge is to truly incorporate biology into our thinking. A child suffers malnutrition and, as an adult, has poor cognitive skills. That’s easy to frame biologically—malnutrition impairs brain development. Alternatively, a child is raised by cold, inexpressive parents and, as an adult, feels unlovable. It’s harder to think those two biologically, to resist thinking that somehow this is a less biological phenomena than the malnutrition/cognition link. There may be less known about the biological changes explaining the link between the cold parents and the adult with poor self-esteem than about the malnutrition/cognition one. It may be less convenient to articulate the former biologically than the latter […] But biology mediates both links. A cloud may be less tangible than a brick, but it’s constructed with the same rules about how atoms interact.”

Sapolsky challenges his readers to think biologically, and this means thinking in a multifactorial manner. Biology has made great strides in explaining aspects of behavior we tend to think of as outside the realm of hard science. These may defy our intuitive understandings of what anatomy, chemistry, life-history, and will really mean in our lives, but this doesn’t change the science. Note at the end of this passage Sapolsky invokes the common symbol of chaos theory, the rain cloud. Though less tangible and comprised of many more variables, the cloud is just as subject to cause and effect as any more easily determinable object.

“Neon lights! This is crucial: study a gene in only one environment and, by definition, you’ve eliminated the ability to see if it works differently in other environments [in other words, if other environments regulate the gene differently]. And thus you’ve artificially inflated the importance of the genetic contribution.”

Geneticists work to determine heritability scores, which is the degree to which the variation in a trait is controlled by genetics. However, science is limited by practical concerns that muddle the effectiveness of this method: few geneticists get to analyze their plant in both Boston and Borneo. We often inflate the importance of genes in influencing behavior by downplaying how much effect environment really has, which can only be discovered by studying the gene and the trait in multiple different environments. As Sapolsky says more succinctly later “it’s not meaningful to ask what a gene does, just what it does in a particular environment” (248).

“Urbanized humans do something completely unprecedented among primates—regularly encountering strangers we never see again, fostering the invention of the anonymous act. After all, it wasn’t until 19th-century urbanization that crime fiction was invented, typically set in cities—in traditional settings there’s no whodunit, since everyone knows what everyone dun.”

Related to the concept of the civilizing process the social structure of living in cities—a blip in the history of the human species—causes different cultural forms and norms to emerge. Suddenly, unlike in small-scale societies, we could be anonymous. This required new social systems to come into being. One example is “Big Gods”: omniscient, punitive deities that will catch you if you do wrong, even if your neighbors don’t.

“As noted, HGs pioneered human cooperative hunting and sharing among nonrelatives. This is most striking with meat […] There are fascinating hints about the antiquity of this. Big-game hunting by hominins 400,000 years ago has been documented; bones from animals butchered then show cut marks that are chaotic, overlapping at different angles, suggesting a free-for-all. But by 200,000 years ago the contemporary HG pattern is there—cut marks are evenly spaced and parallel, suggesting that single individuals butchered and dispensed the meat.”

Among all the discussion of neurons, gene/environment interactions, and chemical signaling, Sapolsky briefly takes a detour into archaeology. In doing so, he gives us another insight into the scientific method and how small pieces of data like the direction and regularity of cut-marks on bones tell us about the social organization of those groups doing the cutting.

“Are we pair bonded or tournament species? Western civilization doesn’t give a clear answer. We praise stable devoted relationships yet are titillated, tempted, and succumb to alternatives at a higher rate […] Anthropology doesn’t help either. Most cultures have allowed polygyny but within such cultures most people are (socially) monogamous […] Measure after measure, it’s the same. We aren’t classically monogamous or polygamous.”

The question of whether we are by nature polygamous or monogamous (tournament species or pair-bonded species) is irresistible to many who would like to shake off puritanical constraints on sexuality. Here, however, biology, anthropology, and sociology seem to let us down because the data says we float somewhere in the middle. (See, however, Richard Wrangham’s The Goodness Paradox, mentioned in Further Reading and Resources).

“From massive, breathtaking barbarity to countless pinpricks of micro-aggression, Us vs. Them has produced oceans of pain. Yet our generic goal is not to cure us of Us/Them dichotomizing. It can’t be done, unless your amygdala is destroyed, in which case everyone seems like an us. But even if we could, we wouldn’t want to eliminate Us/Theming. […] Some of the most exquisitely happy moments of my life have come from feeling like an Us.”

The opposite of love isn’t hate; it’s indifference. Love and hate, and being Us versus being Them comes as a package in our evolution. Both can have negative and positive consequences, and without the brain regions associated with this process we become socially braindead.

“Much as with our ability to detect Thems, we’re intensely interested in and adept at spotting rank differences. For example, 40 milliseconds is all we need to reliably distinguish between a dominant face and a subordinate one […] Status is also signaled in the body […] dominance with an exposed torso with arms wide open, subordination with arms sheltering a bent torso […] Again, we recognize those cues at automatic speeds.”

As much of Sapolsky’s book works to show, the structure of our social systems, from top to bottom, are products of our evolved psychology. As a highly social species, we are also highly hierarchical and incredibly adept at detecting our position within hierarchies relative to others. Like most animals, these detections of hierarchy are quick, unconscious, and automatic but can have incredibly long-lasting effects on our lives.

“The issue isn’t how a few bad apples can ruin the whole barrel, it’s how a bad barrel can turn any apple bad. […] Rather than concentrating on one evil person at a time, what Zimbardo calls a ‘medical’ approach, one must understand how some environments cause epidemics of evil, a ‘public health’ approach. As he states: ‘any deed, for good or evil, that any human being has ever done, you and I could also do—given the same situational forces.’”

The results of Asch, Milgram, and Zimbardo’s experiments on the role of authority and environment in compliance are stunning. Though challenged, they indicate a terrifying truth of human existence: we mostly go along with whatever environment we are born into, regardless of the inherent morality or immorality of this environment. While this is adaptive and helps us to cope, survive, and thrive, it can also lead to some of the greatest crimes in human history. However, these studies also show the power of culture in shaping us toward upstanding behaviors, as Sapolsky further outlines in his discussion of emergent, non-aggressive baboon culture in Chapter 17 (648-49).

“When [Buddhist monk Mathieu Ricard] was confronted with examples of human suffering and instructed to empathically feel the pain of those people, Ricard showed activation of the same circuitry as you’d see in most everyone else. And it was extremely aversive—‘the empathic sharing very quickly became intolerable to me and I felt emotionally exhausted,’ he explained. When instead he did his Buddhist thing, focusing on thoughts of compassion, a totally different picture of activation emerged—the amygdala was silent, and instead there was a heavy activation of the mesolimbic dopamine system. He described it as a ‘warm positive state associated with a strong prosocial motivation.’”

This passage occurs near the end of Sapolsky’s chapter on the affective and effective differences of empathy, sympathy, and compassion. To achieve a sustainable form of compassion in which we take action to help others in need, we must resist the urge to fully take on the sense of pain of another as if it is that of ourselves. Instead, we must train ourselves toward automatic, objective compassion, as Buddhists do through meditation.

“Everything about our hominin past has honed us to be responsive to one face at a time, to a face that is local and familiar, to a source of pain that we ourselves have suffered. Yes, best that our compassion be driven by the most need rather than by the most readily shared pain. Nevertheless, there’s no reason why we should expect ourselves to have particularly good intuitions when aiming to heal this far-flung heterogeneous world. We probably need to be a bit easier on ourselves in this regard.”

The issue of lack of compassion toward developing nations is a major one for global health, prosperity, and future. Here Sapolsky offers an evolutionary explanation for why we offer so little to charity and tend not to sacrifice all that we have for strangers. Forgiving ourselves for not being perfect is the first (but only the first) step to living an effective, compassionate life.

“Mandela, while at Robin Island, had taught himself the Afrikaans language and studied Afrikaans culture—not just to literally understand what his captors were saying among themselves at the prison but to understand the people and their mindset. At one point just before the birth of a free South Africa, Mandela entered into secret negotiations with the Afrikaans leader General Constand Viljoen.… They met in Mandela’s house, with the general apparently anticipating tense negotiations across a conference table. Instead a smiling, cordial Mandela led him to the warm, homey living room, sat beside him on a comfy couch designed to soften the hardest of asses, and spoke to the man in Afrikaans, including small talk about sports, leaping up now and then to get the two of them tea and snacks […] Viljoen was stunned by Mandela’s use of Afrikaans and warm, chatty familiarity with Afrikaans culture. […] Over the course of the conversation, Mandela persuaded Viljoen to call off the armed insurrection and to instead run in the upcoming election as an opposition leader.”

In chapter 15, Sapolsky discusses the danger of our human metaphors. They allow us to believe others are disgusting and less than human. Creating sacred values also creates sticking points that inspire recalcitrance in diplomatic efforts when these sacred values are not heeded or understood. Now, at the end of the chapter, Sapolsky highlights how our penchant for sacred values can also become the most important tools in making peace. This requires acknowledging the sacred values of the other, living by their metaphors, and encouraging them to see us as participants in a shared sacred cause. Mandela, the man who ended Apartheid in South Africa, is a stunning example of this process.

“The biology of the behaviors that interest us is, in all cases, multifactorial—that is the thesis of this book.”

No aspect of biology divorced from its context, can be understood as causal to behavior. But brain systems, stimuli, genetics, personal history, immediately preceding experience, and mood all have biological effects, and these effects, in synthesis, shape and predict behavior. Therefore, to understand behavior in light of biology requires a multifactorial approach.

“Somewhere between neurons, hormones, and genes on one hand and culture, ecological influences, and evolution on the other, sits the individual. And with more than 7 billion of us, it’s easy to feel that no single individual can make much of a difference. But we know that’s not true.”

Summing up his book, Sapolsky places the individual squarely at the intersection of genetics and culture, though as we know by now, these two terms are not completely discrete. Across the book, we have been reminded again and again of the many determining factors on our behavior and the many ways in which free will cannot even be understood to exist. However, as Sapolsky has also noted, making choices, creating patterns, and thinking logically and purposefully about the kind of life we want to pursue can have incredible effects not only for us but also for all those around us. Cultural change and evolution both pivot on the decisions of individuals.