Behave: The Biology of Humans at Our Best and Worst

by Robert M. Sapolsky

  Grossman’s premise is supported by something new and startling. Since it morphed from “battle fatigue” or “shell shock” into a formal psychiatric illness, combat PTSD has been framed as a result of the sheer terror of being under attack, of someone trying to kill you and those around you. As we’ve seen, it is an illness where fear conditioning is overgeneralized and pathological, an amygdala grown large, hyperreactive, and convinced that you are never safe. But consider drone pilots—soldiers who sit in control rooms in the United States, directing drones on the other side of the planet. They are not in danger. Yet their rates of PTSD are just as high as those of soldiers actually “in” war.

  Why? Drone pilots do something horrifying and fascinating, a type of close-range, intimate killing like nothing in history, using imaging technology of extraordinary quality. A target is identified, and a drone might be positioned invisibly high in the sky over the person’s house for weeks, the drone operators always watching, waiting, say, for a gathering of targets in the house. You watch the target coming and going, eating dinner, taking a nap on his deck, playing with his kids. And then comes the command to fire, to release your Hellfire missile at supersonic speed.

  Here’s one drone pilot, describing his first “kill”—three Afghanis targeted from his air force base in Nevada. The missile has hit, and he watches through an infrared camera, which transmits heat signatures:

  The smoke clears, and there’s pieces of the two guys around the crater. And there’s this guy over here, and he’s missing his right leg above his knee. He’s holding it, and he’s rolling around, and the blood is squirting out of his leg, and it’s hitting the ground, and it’s hot. His blood is hot. But when it hits the ground, it starts to cool off; the pool cools fast. It took him a long time to die. I just watched him. I watched him become the same color as the ground he was lying on.45

  But there would be more. Pilots wait to see who retrieves the bodies, who comes to the funeral, ready to perhaps release another strike. Or in other circumstances the pilot might watch as an American convoy approaches a roadside IED booby trap, unable to warn them, or watch insurgents execute a shrieking civilian begging for mercy.

  The pilot above was twenty-one when he made that first kill; he would eventually accumulate 1,626 drone-mediated kills.* No personal danger, an omnipresent eye in the sky. He could finish his shift and get a doughnut on the way home. Yet he and many of his fellow drone pilots succumb to devastating PTSD.

  After reading Grossman, the explanation is simple. The deepest trauma is not the fear of being killed. It’s doing the close-up, individuated killing, watching someone for weeks and then turning him the color of the ground. Grossman cites that during World War II there were low rates of psychiatric breakdowns among sailors and medics—people who were just as endangered as infantrymen but killed either impersonally or not at all.

  Militaries train soldiers to override their inhibitions against killing, and Grossman notes that the training has become more effective—trainees no longer fire at bull’s-eyes; instead it’s rapid-fire situations of mobile virtual-reality figures coming at you, where shooting becomes reflexive. In the Korean War, 55 percent of American riflemen fired their weapons; in the Vietnam War, over 90 percent. And this was before the rise of violent, desensitizing video games.

  Maybe there will soon be completely different types of wars. Perhaps drones themselves will decide when to fire. Maybe wars will consist of autonomous weapons fighting each other, or each side racing to win with the most effective cyberattack on the other’s computers. But as long as we still see the faces of those we kill, this seemingly natural inhibition will be vital.

  THE POSSIBILITIES

  It’s remarkable the things humans can spend their lives studying. You can be a coniologist or a caliologist, studying dust or birds’ nests, respectively. There are batologists and brontologists, pondering brambles and thunder, and vexillologists and zygologists, with their dazzling knowledge of flags and of methods for fastening things. On and on—odontology and odonatology, phenology and phonology, parapsychology and parasitology. A rhinologist and a nosologist fall in love and have a child who becomes a rhinological nosologist, studying the classification of nose diseases.

  The preceding pages suggest the possibility of “peaceology,” the scientific study of the effects of trade, demographics, religion, intergroup contact, reconciliation, and so on, on the ability of humans to live in peace. An intellectual venture with great potential to help the world.

  But with each new example of us at our worst, from the pinpricks of petty meanness to massive carnage, this intellectual venture can feel like rolling a boulder uphill. And thus, to falsely separate cognition and affect, we conclude these many pages by fueling the emotional rather than intellectual certainty that there is hope, that things can change, that we can be changed, that we personally can cause change.

  Rousseau with a Tail

  For more than thirty years I spent my summers studying savanna baboons in the Serengeti ecosystem in East Africa. I love baboons, but I must admit that they’re often violent and abusive, so that the weak suffer at the canines of the strong. Okay, some detachment—they’re a highly sexually dimorphic tournament species with extensive escalated aggression and a strong propensity toward frustration displacement—i.e., they can be intensely shitty to one another.

  —

  In the mid-1980s the baboon troop adjacent to my study group hit the jackpot. Their territory included a tourist lodge; as at tourist places anywhere in the wilds, it had always been a challenge keeping wildlife from feeding on food garbage. Hidden in a grove of trees far from the lodge was a deep garbage pit, surrounded by a fence. But baboons climb fences, fences get knocked down, gates are left open—and that neighboring troop had taken to foraging daily in the dump. Like another widely dispersed primate, humans, baboons eat almost anything—fruit, plants, tubers, insects, eggs, prey they’ve killed, dead things they’ve scavenged.

  The remainders of one of my males, the morning after being attacked by a coalition of rivals

  This transformed the “Garbage Dump” troop. Baboons normally descend from their sleeping trees at dawn and walk ten miles a day foraging. Garbage Dumpers slept in trees above the dump, waddled down at eight o’clock to meet the garbage tractor from the lodge, spend ten minutes in frenzied competition for discarded roast beef and drumsticks and plum pudding, and then waddle out for a nap. I’d even darted Garbage Dump animals and studied them with colleagues—they put on weight, thickened with subcutaneous fat, had elevated circulating levels of insulin and triglycerides, had the start of metabolic syndrome.46

  Breakfast time, as garbage is dumped from a cart

  Somehow baboons in “my” troop got word of the feasting over the hill, and soon half a dozen would head over each morning to join. It wasn’t random who did this, who would try to compete for food against fifty or sixty Thems. The ones who tried were male, big, and aggressive. And morning is when baboons do much of their socializing—sitting in contact, grooming, playing—so going for garbage meant forgoing the socializing. The males who went each morning were the most aggressive, least affiliative members of the troop.

  Not long after, there was a tuberculosis outbreak among the Garbage Dump baboons. In humans tuberculosis is a chronic disease, slowly consuming you with “consumption.” In nonhuman primates, TB is wildfire, spreading rapidly, killing within weeks. Kenyan wildlife vet colleagues and I identified the cause of the outbreak—the meat inspector at the lodge was being bribed to approve tubercular cows for slaughter; animals were killed, unsightly lesionish organs discarded and then consumed by baboons. Most of the Garbage Dump troop died, as did all my males who raided the dump.47

  This was kinda upsetting to me; I habituated a new troop at the other end of the park and wouldn’t go anywhere near the remnants of my troop for half a dozen years. Finally, my soon-to-be wife visiting Kenya for the fi
rst time, I worked up the nerve to return to the troop, to show her the baboons of my youth.

  They were unlike any baboon troop documented, exactly like what you’d expect if you eliminated half the adult males, producing a 2:1 female-to-male ratio instead of the typical 1:1, and if the males remaining were particularly unaggressive and affiliative.48

  They stayed close together, sat in contact, and groomed more than average. Levels of aggression were lower, and in an informative way. Males still had a dominance hierarchy; number three would still fight with numbers four and two, defending his status and seeking a promotion. But there was minimal displacement aggression onto innocent bystanders—when number three lost a fight, he’d rarely terrorize number ten or a female. Stress hormone levels were low; the neurochemistry of anxiety and benzodiazepines worked differently in these individuals.

  Here’s a measure of it, a picture that, if you’re a baboon-ologist, is more surprising than one showing baboons inventing the wheel—two adult males grooming. That hardly ever happens. Except in this troop.

  And now the most important part. Female baboons remain in their birth troop, whereas males get itchy around puberty and leave, trying their luck anywhere from the troop next door to one thirty miles away. By the time I returned to this troop, most of the males who had avoided the TB had died; the troop was filled with males who had transferred in after the TB. In other words, adolescent males had grown up in typical baboon troops and then joined this one and adopted the style of low aggression and high affiliation. The troop’s social culture was being transmitted.

  How? Adolescents who joined the troop were no less aggressive or displacing than those joining other troops—there wasn’t self-selection. There was no evidence of social instruction occurring. Instead the most likely explanation involved resident females. These were probably the least stressed female baboons on earth, not being subject to typical male displacement aggression. In this more relaxed state, they were more willing to risk affiliative overtures to new individuals—in a typical baboon troop it is more than two months before females first groom or sexually solicit new transfer males; in this troop it was a matter of days to weeks. Coupled with the lack of displacement aggression from resident males, this caused the new-transfer males to gradually change, assimilating into the troop culture in about six months. Thus, when treated in a less aggressive, more affiliative manner, adolescent baboons start doing the same.

  In 1965 a rising star of primatology, Irven DeVore of Harvard, published the first overview of the subject.49 Discussing his own specialty, savanna baboons, he wrote that they “have acquired an aggressive temperament as a defense against predators, and aggressiveness cannot be turned on and off like a faucet. It is an integral part of the monkeys’ personalities, so deeply rooted that it makes them potential aggressors in every situation.” Thus savanna baboons became, literally, textbook examples of an aggressive, stratified, male-dominated primate. Yet as we see here, this picture is not universal or inevitable.

  Humans have formed both small nomadic bands and megastates and have demonstrated a flexibility whereby uprooted descendants of the former function in the latter. Human mating patterns are atypically flexible, and our societies feature monogamy, polygyny, or polyandry. We have fashioned religions where certain types of violence earn you paradise and others where the same violence consigns you to hell. Basically, if baboons unexpectedly show this much social plasticity, so can we. Anyone who says that our worst behaviors are inevitable knows too little about primates, including us.

  One Person

  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 seven 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. There’s the obligatory list of those who changed everything—Mandela, Gandhi, MLK, Rosa Parks, Lincoln, Aung San Suu Kyi. Yes, they often had scads of advisers. But they were the catalysts, the ones who paid with their freedom or their lives. And there are whistle-blowers who took great risks to trigger change—Daniel Ellsberg, Karen Silkwood, W. Mark Felt (Watergate’s Deep Throat), Samuel Provance (the U.S. soldier who revealed the abuses at Abu Ghraib Prison), Edward Snowden.*

  But there are also lesser-known people, acting alone or in small numbers, with extraordinary impact. Take Mohamed Bouazizi, a twenty-six-year-old fruit seller in Tunisia, then in its twenty-third year of corrupt and repressive rule by a dictator. At the market the police hassled Bouazizi about an imaginary permit, expecting a bribe. He refused, not out of principle—he’d often bribed—but because he lacked the money. He was kicked and spat upon, his fruit cart overturned. His complaint at the government office was ignored. And within an hour of being preyed upon by the police, on December 10, 2010, Bouazizi stood in front of that office, doused himself with gasoline, shouted, “How do you expect me to make a living?” and set himself on fire.

  Bouazizi’s immolation and death triggered protests in Tunisia against the leader, Zine El Abidine Ben Ali, against his ruling party, against the police. The protests grew, and within a month the government and Ben Ali were overthrown. Bouazizi’s act led to protests in Egypt, toppling Hosni Mubarak’s thirty-year dictatorship. Likewise in Yemen, ending Ali Abdullah Saleh’s thirty-four-year rule. And in Libya, leading to the overthrow and killing of Muammar Gaddafi after forty-three years in power. And in Syria, where protests morphed into civil war. And in Jordan, Oman, and Kuwait, leading to the resignations of their prime ministers. And in Algeria, Iraq, Bahrain, Morocco, and Saudi Arabia, producing semblances of governmental reform. The Arab Spring. Bouazizi wasn’t thinking about political reform in the Muslim world when he lit the match; instead there was rage with nowhere to go but inward. Make what you will of the Arab Spring’s brief hopefulness, followed by new strongmen, violence, refugees, and the catastrophe of Syria and ISIS. And perhaps history makes the self-immolator as much as the self-immolator makes history—regional discontent had long been brewing. Regardless, Bouazizi’s singular act catalyzed millions in twenty countries to decide that they could cause change.

  Antigovernment protestors displaying a picture of Bouazizi

  There have been other singular acts. In the mid-1980s a commemoration was being held at the Pearl Harbor Memorial on the anniversary of the attack. A group of survivors who had gathered were approached by an elderly man. This was his third trip to the memorial, trying to work up his nerve. He approached the survivors and, in halting English, apologized.50

  The man, Zenji Abe, was a fighter pilot in the 1937 Japanese invasion of China and throughout the Pacific during World War II—including helping to lead the attack on Pearl Harbor.

  Little in his earlier life predicted Abe’s apologizing as an old man. His inculcation into war started early, when he joined a military academy as a seventh grader. His experience of war was detached—he never killed an American soldier at close quarters. The Pearl Harbor attack felt like a training exercise. His sense of responsibility could readily have been blunted, as the bomb he dropped hadn’t detonated. And his country had been defeated.

  Some things favored Abe’s gesture. He had been captured and spent a year as a POW, treated decently by Americans. And he felt shame about the attack—pilots had been told that war against America had been declared that morning, that American defenses would be ready. He soon learned that instead it was a sneak attack.

  Some larger factors favored his gesture as well. Japanese/American relations had transformed. And Americans were not traditional enemies. The racial, cultural, and geographic distance might have facilitated pseudospeciation of Americans, but it was nouveau pseudospeciation, contrasting with centuries of hatred of a nearby enemy—Abe never went to China to apologize for the Rape of Nanking. As we know, Thems come in different categories.

  So these likelihoods and unlikelihoods converged, and
Abe stood there, along with nine other pilots who had flown that day, apologizing. Some survivors refused the overture. Most accepted it. Abe and other pilots made subsequent trips to Pearl Harbor and had multiday meetings with American survivors; reconciliative handshakes were broadcast on the Today show for the fiftieth anniversary. Survivors generally considered the pilots to have just been following orders and found their current actions brave and admirable. Abe became close with one survivor, Richard Fiske, a docent at the memorial. Fiske had been on one of the ships during the attack, lost many friends among the 2,390 Americans killed, fought at Iwo Jima, described himself as so hating the Japanese that he developed a bleeding ulcer. For reasons he never fully understood, Fiske was the first to accept Abe’s gesture. Other Japanese and Americans became close as well, visiting the homes and, eventually, the grave sites of their ex-enemies.

  Left: Zenji Abe, December 6th, 1941; right: Abe and Richard Fiske, December 6th, 1991

  The process was rich in symbols, starting with an apology that, as we’ve seen, changes nothing and everything. Abe gave Fiske money so that, for the rest of his life, Fiske placed flowers monthly at the memorial. Fiske, a bugler, took to playing not only taps at the memorial, but the Japanese equivalent as well. Some semblance of Us-ness had emerged that included everyone there that infamous day.