testosterone, 90, 99–107, 151, 158, 432, 444, 708
aggression and violence and, 100–102, 107, 115, 135, 170, 215, 216, 218–20, 259–60
papers published on, 605
challenge hypothesis of, 105–7, 435
contingent effects of, 104–5, 115
in females, 119–21
genes and, 227, 259–60
math skills and, 266
prenatal, 211–20
prosocial and nurturing behaviors and, 106n
social rank and, 435
subtleties of effects of, 102–4
winning and, 102, 103, 105
Theory of Mind (ToM), 114, 177–81, 206, 274, 275, 411n, 429, 430, 433, 475, 480, 515, 527, 531, 533, 617–18
mirror neurons and, 538
religion and, 622
Thinking, Fast and Slow (Kahneman), 512n
Thomas, Elizabeth Marshall, 319
Thompson, Hugh, Jr., 657–58, 658, 660, 661, 670
Thompson-Cannino, Jennifer, 641–42
threat perception, 451–52, 561–62
Tierney, Patrick, 312n
Tinbergen, Niko, 83n
Tit for Tat, 346–53, 363, 634, 666
Contrite, 350
Forgiving, 350, 351
Tomasello, Michael, 486
tool use, 269, 270, 523
tournament species, pair bonding vs., 354–58, 360, 383
Toxoplasma gondii, 151, 219
trade, 620–21
tragedy of the commons vs. tragedy of commonsense morality, 508–11, 533
transcription factor (TF), 226–29, 233
transgender individuals, 215n
Treachery of Images, The (Magritte), 556–57, 556
Trench Warfare: 1914–1918 (Ashworth), 665, 666
Trip to the Moon, A, 398
Trivers, Robert, 344, 384
trolley problem (killing one person to save five), 55, 56, 58–59, 117, 482, 488–91, 505–7
self-driving cars and, 612n
trust, 112–13, 116, 292, 496
chimpanzees and, 393
truth and reconciliation commissions (TRC), 638–39, 642
tryptophan hydroxylase (TH), 251
Tsai, Jeanne, 275
Tunisia and the Arab Spring, 652–53
Turchin, Peter, 291
Tutsi and Hutu tribes, 372, 469, 570–73
Tutu, Desmond, 639
Tversky, Amos, 93
Twinkie defense, 92n
twins, 336, 717
studies of, 234–41
Tylor, Edward, 269
UCLA, 502–3
Uganda, 414
Ultimatum Game, 38–39, 106, 486, 497, 498, 500, 610, 635
unconscious and subliminal cuing, 84–90, 93–96
language, 92–93
United States:
ethnicity in, 395
individualism in, 277
regionalism in, 288
South in, 181n, 207, 284–88, 501
urban living, 296, 298–99
Us and Them: The Science of Identity (Berreby), 399
Us/Them dichotomies, 387–424, 425, 478, 493, 526
in children, 391–92
conformity and, 470
converts and, 397
and discrepancies between what people claim to believe and how they act, 416–18
disgust and, 398–99
elimination of, 423
empathy and, 532–35
essentialism and, 399, 407, 423
individuation vs., 420–21
frontal cortex and, 416–17
hierarchies and, 421–22, 425
honorable enemy phenomenon and, 414, 415
Implicit Association Test (IAT) and, 116, 388, 389, 416, 582
magical contagion and, 403
manipulation of, 418–22, 469
by changing rank ordering of categories, 419–20
by contact, 420, 626–30
by cuing and priming, 418–19
to decrease implicit biases, 419, 643
essentialism vs. individuation in, 420–21
hierarchies in, 421–22
minimal, arbitrary groupings in, 389–91, 393
oxytocin and, 116–17, 389
race and, 406–8
self-hating and, 415
strength of, 388–93
Them in, 398–405
dehumanization and pseudospeciation of, 372, 570, 572–73, 574, 632–33
different feelings about different types of, 410–11
individual vs. group interactions with, 404–5
oxytocin and, 116–17, 135, 614
religion and, 624
thoughts vs. feelings about, 400–404
uniquely human realms of, 405–18
Us in, 393–97
multiple categories of, 405–10, 491
warmth and competence categories in, 410–15, 522
values, sacred, in conflict resolution, 575–79, 643–44
vasopressin, see oxytocin and vasopressin
Vietnam War, 415, 624, 647, 664
My Lai Massacre in, 464, 655–58, 657, 658
Viljoen, Constand and Abraham Viljoen, 578, 670
violence, 2–4, 11, 15
in adolescence, 170–71
in American South, 285–88, 286, 501
context of, 3
in crime waves of 1970s and 1980s, 311
crowding and, 298–99
culture and, 272
decline in, 306, 615–21
fear and, 44
frontal cortex and, 54
genes and, 224
hot-blooded vs. cold-blooded, 18
in hunter-gatherer societies, 319–25, 322
income inequality and, 295
incompetence at and aversion to, 644–47
intrafamily, 369–70
media, 198, 206–7
observing in childhood, 197–98
in prehistoric and indigenous cultures, 306–15
psychopathic, 44
religion and, 624
reproductive success and, 367
serotonin and, 76–77
temperature and, 303
testosterone and, 170
see also aggression
virtue ethics, 504, 520
visual spectrum, 6
visual stimuli, 6, 84
voles, 110–11, 113n, 116, 229, 525–26, 530
Voltaire, 383
Von Frisch, Karl, 83n
Von Neumann, John, 345
voting, 237, 403, 442–44, 451
Wall, Patrick, 699
Wallace, Alfred Russel, 230n
Wallen, Kim, 215
war and peace, 614–70
Civil War, 409, 662
Battle of Gettysburg, 554, 644
collective power and, 662–68
contact and, 420, 626–30
decline in violence, 306, 615–21
fraternizing between enemy soldiers, 662
Golden Arches theory of peace, 620
individuals making a difference, 652–61
religion and, 621–26
trade and, 620–21
Vietnam War, 415, 624, 647, 664
My Lai Massacre in, 464, 655–58, 657, 658
World War I, 394–95, 414, 619–21, 662–68, 670
Christmas truce in, 410, 663–65, 663, 667
Live and Let Live truces in, 665–67
propaganda posters in, 667
World War II, 202, 308, 404, 410, 413, 618, 619, 645–47
Japanese in, 413, 640, 653–55, 668, 669
&
nbsp; War Before Civilization: The Myth of the Peaceful Savage (Keeley), 306
Washington, Booker T., 642
Watergate, 652
Watson, James, 714
Watson, John, 8–9, 82
weaning conflict, 358
weather, 302–3
Wegner, Daniel, 62
Wellesley effect, 11, 90
Wendorf, Fred, 308
Westermarck effect, 371
Weyer, Johann, 584
Wheeler, Mary, 408
White, Dan, 92n
Whiten, Andrew, 458
Whitman, Charles, 33
Who’s in Charge? Free Will and the Science of the Brain (Gazzaniga), 591
Wiesel, Elie, 19
Wiessner, Polly, 324
Wilberforce, William, 659
Wilde, Oscar, 509
Wilkinson, Richard, 294
Williams, George, 333
Williams, Robin, 17n
willpower, 91, 449
Wilson, Allan, 228
Wilson, Margo, 367
Wilson, David Sloan, 364
Wilson, E. O., 364, 383–84
Wilson, James Q., 95
Wingfield, John, 105
winning, 102, 103, 105
witchcraft, 583–84, 606–8
Woodward, James, 506–8
Worchel, Stephen, 628
word definitions, 15–16, 18, 20
World War I, 394–95, 414, 619–21, 662–68, 670
Christmas truce in, 410, 663–65, 663, 667
Live and Let Live truces in, 665–67
propaganda posters in, 667
World War II, 202, 308, 404, 410, 413, 618, 619, 645–47
Japanese in, 413, 640, 653–55, 668, 669
Wrangham, Richard, 314, 316–17
Wyatt-Brown, Bertram, 285
Wynn, Karen, 484
Wynne-Edwards, V. C., 332
Yanomamö, 311–14, 316, 319
Yanomamo: The Fierce People (Chagnon), 312
Young, Larry, 110, 526
zero-sum games, 394–95
Zhong, Chen-Bo, 564
Zimbardo, Philip, 461, 463–68, 475
Zulus, 310, 310
Robert M. Sapolsky is the author of several works of nonfiction, including A Primate’s Memoir, The Trouble with Testosterone, and Why Zebras Don’t Get Ulcers. He is a professor of biology and neurology at Stanford University and the recipient of a MacArthur Foundation genius grant. He lives in San Francisco.
* Shortly after making this pronouncement, Watson fled academia amid sexual scandal. He eventually resurfaced as the vice president of an advertising company. You may not be able to shape people into anything you wish, but at least you can often shape them into buying some useless gewgaw.
* I recently found a startling example of unorthodox defining of terms. This concerned Menachem Begin, one of the surprising architects of the Camp David Peace Accords in 1978 as the prime minister of Israel. In the mid-1940s he headed the Irgun, the Zionist paramilitary group intent on driving Britain out of Palestine in order to facilitate the founding of Israel. The Irgun raised money to buy arms through extortion and robbery, hanged two captive British soldiers and booby-trapped their bodies, and carried out a series of bombings including, most notoriously, an attack on British headquarters at Jerusalem’s King David Hotel, an act that killed not only numerous British officials but also scores of Arab and Jewish civilians. And Begin’s account of these activities? “Historically we were not ‘terrorists.’ We were, strictly speaking, anti-terrorists” (my emphasis).
* I’ve observed a remarkable example of this among the baboons that I’ve studied in East Africa. Over the thirty-odd years I’ve watched them, I’ve seen a handful of instances of what I believe warrants the seemingly human-specific term “rape”—where a male baboon will forcibly vaginally penetrate a female who is not in estrus, who is not sexually receptive, who struggles to prevent it, and who gives every indication of distress and pain when it happens. And each of these instances has been the act of the former alpha male in the hours after he has been toppled from his position.
* There is a great contemporary version of human ritualistic aggression, namely the haka ritual performed by rugby teams from New Zealand. Just before the game starts, the Kiwis line up midfield and perform this neo-Maori war dance, complete with rhythmic stamping, menacing gestures, guttural shouting, and histrionically threatening facial expressions. It’s cool to see from afar on YouTube (even better is watching the YouTube clip of Robin Williams doing a haka display at Charlie Rose on PBS), while up close it typically appears to scare the bejesus out of the other team. However, some opposing teams have come up with ritualistic responses straight out of the baboon playbook—getting in the haka-ers’ faces and trying to stare them down. Other teams come out with ritualistic responses that are pure human uniqueness—ignoring the haka-ers while nonchalantly warming up; using their smartphones to film the display, thereby emasculating it to something vaguely touristy in flavor; tepidly applauding afterward with great condescension. One response initially seems uniquely human but would be understandable to other primates after some translating—the sports newsletter for one Australian team printed a photo of the mortal enemy New Zealanders doing a haka, with each player brandishing a Photoshopped woman’s handbag.
* A fascinating, grotesque example of this is Munchausen Syndrome by Proxy, where a woman (it’s overwhelmingly a female disorder) generates illnesses in her child out of a pathological need for the attention, care, and envelopment of the medical system. This is not someone falsely telling the pediatrician that her child had a fever last night. This is giving children emetics to induce vomiting, poisoning them, smothering them to induce symptoms of hypoxia—often with fatal consequences. One feature of the disorder is a stunning lack of affect in the mothers. One would expect an air of spittle-flecked madness to match the actions. Instead, there is cold detachment, as if they could simply be lying to a veterinarian about their supposedly sick goldfish or to customer service at Sears about their supposedly broken toaster, if doing so would bring the same psychological benefits. For a lengthy overview of Munchausen Syndrome by Proxy, see R. Sapolsky, “Nursery Crimes,” in Monkeyluv and Other Essays on Our Lives as Animals (New York: Simon and Schuster/Scribner, 2005).
* It is also often called the “involuntary nervous system,” contrasting it with the “voluntary nervous system.” The latter is about conscious, voluntary movement and involves neurons in “motor” regions of the brain and their projections down the spine to skeletal muscles.
* Just as a warning of complexities to come, the hypothalamus consists of a bunch of different nuclei, each receiving a unique orchestration of limbic inputs and equivalently distinctive outputs to various midbrain/brain-stem regions. And while each hypothalamic nucleus has a different set of functions, they all fall under the general rubric of autonomic regulation.
* And to needlessly complicate things further, thus explaining why this is buried in a footnote, there is actually an intervening synapse between the long spinal projection neurons of the SNS and the SNS neurons reaching target cells. This is the second neuron in the two-step pathway that releases norepinephrine. The first neuron in each pathway releases acetylcholine.
* Nice logical piece of this: Suppose you’re stressed, not by running for your life from a lion but by having to give a speech. Your mouth gets dry, the first step of your SNS shutting down digestion until a more auspicious time.
* Like the SNS, the PNS gets the brain to target organs via two steps. And as one complication, the SNS and PNS branches aren’t always working in complete opposition; in some cases they function in a more cooperative, sequential manner. For example, erection and ejaculation involve coordination between the SNS and PNS that is so complicated that it’s a miracl
e that any of us were conceived.
* In other words, layers 2 and 3 can influence the autonomic functions of layer 1, which alters events throughout the body, which in turn influences all the parts of the brain. Loops and loops.
* Nauta was not only a towering scientist but also a force of integrity, as well as a renowned teacher who made neuroanatomy, taught in three-hour evening classes, borderline fun. During college I did research in the lab next to his, and I was so in awe of the guy that I’d find every possible autonomic excuse to go to the bathroom whenever I saw him heading in that direction, just for the chance to offhandedly say hello to him by the urinals. (My awe grew further later, with my discovery that he and his family sheltered Jews from Nazis in Holland during World War II and are cited in the Holocaust Museum in Washington, DC.)
* The word is from the Greek ἀμυγδαλἠ (thank you, Wikipedia), which means “almond,” which the amygdala very vaguely resembles. Weirdly, it turns out that the word also means “tonsil,” which must have produced some major malpractice suits when ancient Greeks went in for tonsillectomies.
* The amygdala is one of those “bilateral” structures, meaning that there are two of them, one in each hemisphere, mirroring each other.
* A note about specificity. To be confident that the amygdala really is selectively about aggression, you also have to show that it activates more than do other brain regions and doesn’t activate as much during a hodgepodge of other behaviors.
* Wait, don’t the Marines want you to be physically threatening? Don’t they train you to be that way? This is a great example of the big theme of this book, namely the context dependency of our best and worst behaviors: what the Marines train people for is to be majorly physically threatening . . . in certain contexts only.
* By the way, what does mouse anxiety look like? Mice dislike bright lights and open spaces—go figure, for a nocturnal animal that lots of species like to eat. So one measure of mouse anxiety is how long it takes for a mouse to go into the center of a brightly lit area to get some food.
Behave: The Biology of Humans at Our Best and Worst Page 95