By Robert M. Sapolsky, Penguin Books, May 2, 2017, 978-0143110910

I enjoyed this very long book – read over four months. It’s funny, irreverent, and filled with fascinating facts and ideas. Summary: our behavior is a complicated interplay between environment and genes. There’s no short path to say why we behave the way we behave except by studying all the topics Sapolsky put in this book and then some.

You won’t walk away with that happy feeling of learned something. At least, I didn’t. I felt like there’s so much I don’t know and understand. I like psychology and genetics and moral psychology and … Yet, it’s not something I think I can study enough to actually have a grasp of anything. So I read these types of books to remind myself how little I know, and maybe to remember a factoid or two.

I do like how Sapolsky ends with some societal reforms. He thinks prisons need to be redone, and he presents solid reasons for it. Not that the system will change the way he wants, but at least he presents his ideas cogently, e.g. “But there is simply no place for the idea that punishment is a virtue. Our dopaminergic pathways will have to find their stimulation elsewhere.”

[k1396] And behaviorist rules have failed when humans love the wrong abusive person.

[k1791] In other words, testosterone doesn’t necessarily make you behave in a crappy manner, but believing that it does and that you’re drowning in the stuff makes you behave in a crappy manner.

[k1796] Testosterone makes us more willing to do what it takes to attain and maintain status. And the key point is what it takes. Engineer social circumstances right, and boosting testosterone levels during a challenge would make people compete like crazy to do the most acts of random kindness.

[k1798] In our world riddled with male violence, the problem isn’t that testosterone can increase levels of aggression. The problem is the frequency with which we reward aggression. OXYTOCIN AND VASOPRESSIN: A MARKETING DREAM If the point of the preceding section is that testosterone has gotten a bum rap, the point of this one is that oxytocin (and the closely related vasopressin) is coasting in a Teflon presidency.

[k1961] Oxytocin, the luv hormone, makes us more prosocial to Us and worse to everyone else. That’s not generic prosociality. That’s ethnocentrism and xenophobia. In other words, the actions of these neuropeptides depend dramatically on context–who you are, your environment, and who that person is.

[k2111] Ditto for chronically inhibiting reproductive physiology; you’ll disrupt ovulatory cycles in women and cause plummeting erections and testosterone levels in men.

[k2158] Thus stress facilitates learning fear associations but impairs learning fear extinction.

[k2163] Stress also desynchronizes activation in different frontocortical regions, which impairs the ability to shift attention between tasks.

[k2173] This involves an interesting gender difference–in general, major stressors make people of both genders more risk taking. But moderate stressors bias men toward, and women away from, risk taking.

[k2178] Stated most broadly, sustained stress impairs risk assessment.

[k2200] More bad news: stress biases us toward selfishness.

[k2428] You’ve got your maximal number of neurons around birth, and it’s downhill from there, thanks to aging and imprudence.

[k2465] Adult neurogenesis is the trendiest topic in neuroscience.

[k2478] There’s the ambivalence of someone who spent a long time as a scorned prophet who at least got to be completely vindicated. He’s philosophical about it–hey, I’m a Hungarian Jew who escaped from a Nazi camp; you take things in stride after that.

[k2505] The discovery of adult neurogenesis is revolutionary, and the general topic of neuroplasticity, in all its guises, is immensely important–as is often the case when something the experts said couldn’t be turns out to be.

[k2533] Six Adolescence; or, Dude, Where’s My Frontal Cortex?

[k2545] If by adolescence limbic, autonomic, and endocrine systems are going full blast while the frontal cortex is still working out the assembly instructions, we’ve just explained why adolescents are so frustrating, great, asinine, impulsive, inspiring, destructive, self-destructive, selfless, selfish, impossible, and world changing.

[k2571] Neuronal overproduction followed by competitive pruning (which has been termed “neural Darwinism”) allowed the evolution of more optimized neural circuitry, a case of less being more.

[k2725] Rejection hurts adolescents more, producing that stronger need to fit in. One neuroimaging study.

[k2771] Feeling someone else’s pain is painful, and people who do so most strongly, with the most pronounced arousal and anxiety, are actually less likely to act prosocially.

[k2772] Instead the personal distress induces a self-focus that prompts avoidance–“This is too awful; I can’t stay here any longer.” As empathic pain increases, your own pain becomes your primary concern.

[k2784] Late adolescence and early adulthood are when violence peaks, whether premeditated or impulsive murder, Victorian fisticuffs or handguns, solitary or organized (in or out of a uniform), focused on a stranger or on an intimate partner. And then rates plummet. As has been said, the greatest crime-fighting tool is a thirtieth birthday.

[k2814] If the frontal cortex matured as fast as the rest of the brain, there’d be none of the adolescent turbulence, none of the antsy, itchy exploration and creativity, none of the long line of pimply adolescent geniuses who dropped out of school and worked away in their garages to invent fire, cave painting, and the wheel.

[k2819] I don’t think delayed frontal cortical maturation evolved so that adolescents could act over the top.

[k2830] Adult life is filled with consequential forks in the road where the right thing is definitely harder. Navigating these successfully is the portfolio of the frontal cortex, and developing the ability to do this right in each context requires profound shaping by experience.

[k2835] Ironically, it seems that the genetic program of human brain development has evolved to, as much as possible, free the frontal cortex from genes. Seven Back to the Crib, Back to the Womb After journeying to Planet Adolescence, we resume our basic approach.

[k2972] As noted, high pain thresholds in sociopaths help explain their lack of empathy–it’s hard to feel someone else’s pain when you can’t feel your own.

[k3069] When combined with children-should-be-seen-but-not-heard-ism, this suggested that once you’ve addressed a child’s need for nutrition, proper temperature, plus other odds and ends, they’re set to go. Affection, warmth, physical contact?

[k3066] This period brought one of history’s strangest one-night stands, namely when the Freudians and the behaviorists hooked up to explain why infants become attached to their mothers. To behaviorists, obviously, it’s because mothers reinforce them, providing calories when they’re hungry. For Freudians, also obviously, infants lack the “ego development” to form a relationship with anything/anyone other than Mom’s breasts. When combined with children-should-be-seen-but-not-heard-ism, this suggested that once you’ve addressed a child’s need for nutrition, proper temperature, plus other odds and ends, they’re set to go. Affection, warmth, physical contact? Superfluous.

[k3076] Remarkably, hospitalism soared in hospitals with newfangled incubators (adapted from poultry farming); the safest hospitals were poor ones that relied on the primitive act of humans actually touching and interacting with infants.

[k3087] Freud and B. F. Skinner would have wrestled over access to chicken-wire mom. But infant monkeys chose the terry-cloth mom.*

[k3181] This is so wrong–foolishly pick a poor family to be born into, and by kindergarten, the odds of your succeeding at life’s marshmallow tests are already stacked against you.

[k3234] Kids with the metaphorical “kick me” signs on their backs are more likely to have personal or family psychiatric issues and poor social and emotional intelligence. These are kids already at risk for bad adult outcomes, and adding bullying to the mix just makes the child’s future even bleaker.

[k3239] The second profile is the confident, unempathic, socially intelligent kid with an imperturbable sympathetic nervous system; this is the future sociopath.

[k3720] According to Lamarck, when she has babies, they will have longer necks because of “acquired inheritance.”* Lunatic! Buffoon! Epigenetically mediated mechanisms of inheritance–now often called “neo-Lamarckian inheritance”–prove Lamarck right in this narrow domain. Centuries late, the guy’s getting some acclaim. Thus, not only does environment regulate genes, but it can do so with effects that last days to lifetimes.

[k3737] Oh, and splicing enzymes are proteins, meaning that each is coded for by a gene. Loops and loops.

[k3743] Clearly McClintock, with her (derisively named) “jumping genes,” had gone mad,

[k3742] The only possibility, she concluded, was that stretches of DNA had been copied, with the copy then randomly inserted into another stretch of DNA. Yeah, right. Clearly McClintock, with her (derisively named) “jumping genes,” had gone mad, and so she was ignored (not exactly true, but this detracts from the drama). She soldiered on in epic isolation. And finally, with the molecular revolution of the 1970s, she was vindicated about her (now termed) transposable genetic elements, or transposons. She was lionized, canonized, Nobel Prized (and was wonderfully inspirational, as disinterested in acclaim as in her ostracism, working until her nineties).

[k3752] Plants utilize transposons. Suppose there is a drought; plants can’t move to wetter pastures like animals can. Plant “stress” such as drought induces transpositions in particular cells, where the plant metaphorically shuffles its DNA deck, hoping to generate some novel savior of a protein.

[k3757] The main point here is that transposons occur in the brain. In humans transpositional events occur in stem cells in the brain when they are becoming neurons, making the brain a mosaic of neurons with different DNA sequences. In other words, when you make neurons, that boring DNA sequence you inherited isn’t good enough.

[k4111] Having the low-activity version of MAO-A tripled the likelihood . . . but only in people with a history of severe childhood abuse. And if there was no such history, the variant was not predictive of anything.

[k4113] What does having a particular variant of the MAO-A gene have to do with antisocial behavior? It depends on the environment. “Warrior gene” my ass.

[k4286] Amid all these tiny effects and technical limitations, it’s important to not throw out the genetic baby with the bathwater, as has been an agitated sociopolitical goal at times (during my intellectual youth in the 1970s, sandwiched between the geologic periods of Cranberry Bell-bottoms and of John Travolta White Suits was the Genes-Have-Nothing-to-Do-with-Behavior Ice Age). Genes have plenty to do with behavior.

[k4293] Ask what it does in a particular environment and when expressed in a particular network of other genes (i.e., gene/gene/gene/gene…/environment).

[k6633] In the 1950s the psychologist Gordon Allport proposed “contact theory.” Inaccurate version: if you bring Us-es and Thems together (say, teenagers from two hostile nations brought together in a summer camp), animosities disappear, similarities become more important than differences, and everyone becomes an Us. More accurate version: put Us-es and Thems together under very narrow circumstances and something sort of resembling that happens, but you can also blow it and worsen things.

[k6674] Thus, in order to lessen the adverse effects of Us/Them-ing, a shopping list would include emphasizing individuation and shared attributes, perspective taking, more benign dichotomies, lessening hierarchical differences, and bringing people together on equal terms with shared goals. All to be revisited.

[k6679] It is understood how stress can cause or worsen disease or make you more vulnerable to other risk factors. Much of this is even understood on the molecular level. Stress can even cause your immune system to abnormally target hair follicles, causing your hair to turn gray.

[k6682] we love stress when it’s the right kind; we call it “stimulation.”

[k6691] Keep in mind that what seems like rationality is often just rationalization, playing catch-up with subterranean forces that we never suspect. Focus on the larger, shared goals.

[k6690] If we accept that there will always be sides, it’s a nontrivial to-do list item to always be on the side of angels. Distrust essentialism. Keep in mind that what seems like rationality is often just rationalization, playing catch-up with subterranean forces that we never suspect. Focus on the larger, shared goals. Practice perspective taking. Individuate, individuate, individuate. Recall the historical lessons of how often the truly malignant Thems keep themselves hidden and make third parties the fall guy.

[k6694] And in the meantime, give the right-of-way to people driving cars with the “Mean people suck” bumper sticker, and remind everyone that we’re all in it together against Lord Voldemort and the House Slytherin.

[k6710] a hierarchy is a ranking system that formalizes unequal access to limited resources, ranging from meat to that nebulous thing called “prestige.”

[k6838] I love these findings. As I said, in lots of social species, attaining high rank is about sharp teeth and good fighting skills. But maintaining the high rank is about social intelligence and impulse control: knowing which provocations to ignore and which coalitions to form, understanding other individuals’ actions.

[k7133] Fear, anxiety, the terror of mortality–it must be a drag being right-wing. But despite that, in a multinational study, rightists were happier than leftists.

[k7436] What incrementalism does is put the potential resister on the defensive, making the savagery seem like an issue of rationality rather than of morality.

[k7519] Humans committed themselves to a unique trajectory when we invented socioeconomic status. In terms of its caustic, scarring impact on minds and bodies, nothing in the history of animals being crappy to one another about status differences comes within light-years of our invention of poverty.

[k7618] knowing a judge’s opinions about Plato, Nietzsche, Rawls, and any other philosopher whose name I just looked up gives you less predictive power about her judicial decisions than knowing if she’s hungry.

[k7769] Know thyself. Especially in differing contexts.

[k7802] we have entered complicated terrain when we can make sense of an interchange where a masochist says, “Beat me,” and the sadist sadistically answers, “No.”

[k7839] When they live in a society where people don’t trust one another and feel as if they have no efficacy.

[k7838] The authors found a key correlation–the lower the social capital in a country, the higher the rates of antisocial punishment. In other words, when do people’s moral systems include the idea that being generous deserves punishment? When they live in a society where people don’t trust one another and feel as if they have no efficacy.

[k8051] And it takes a locomotive’s worth of effort for me to admit that I can’t justify that hatred and contempt, that mine is a mere moral intuition, that there are things that I do that would evoke the same response in some distant person whose humanity and morality are certainly no less than mine, and that but for the randomness of where I happen to have been born, I could have readily had their views instead. The thing that makes the tragedy of commonsense morality so tragic is the intensity with which you just know that They are deeply wrong. In general, our morally tinged cultural institutions–religion, nationalism, ethnic pride, team spirit–bias us toward our best behaviors when we are single shepherds facing a potential tragedy of the commons. They make us less selfish in Me versus Us situations. But they send us hurtling toward our worst behaviors when confronting Thems and their different moralities.

[k8105] The human capacity for deception is enormous.

[k8171] A pattern of brain activation before each round’s decision predicted breaking of a promise.

[k8592] Thus, if feeling your pain makes me feel awful, I’m likely to just look out for number one, rather than helping you.

[k8596] Mogil’s group (with my involvement) recently showed that if you use a drug to block glucocorticoid secretion, both mice and humans become more empathic toward strangers. Thus, if you feel highly distressed, whether due to resonating with someone else’s problems or because of your own, tending to your own needs readily becomes the priority.

[k8624] There is the realm of what has been termed “pathological altruism,” the type associated with codependency. This is the scenario of someone so consumed with the vicarious pain of a loved one that they endure and facilitate his dysfunction rather than administering tough love. Then there’s the danger that the empathic pain is so intense that you can only come up with solutions that would work for you, rather than ones that might help the sufferer.

[k8630] A large piece of the training of health-care professionals is teaching them to keep empathy at bay.

[k8713] Better that our good acts be self-serving and self-aggrandizing than that they don’t occur at all; better that the myths we construct and propagate about ourselves are that we are gentle and giving, rather than that we prefer to be feared than loved, and that we aim to live well as the best revenge.

[k8716] I’m not advocating that people become Buddhists in order to make the world a better place. (Nor am I advocating that people don’t become Buddhists; what is the sound of one atheist waffling?)

[k8722] Which brings us to a final point. Yes, you don’t act because someone else’s pain is so painful–that’s a scenario that begs you to flee instead. But the detachment that should be aimed for doesn’t represent choosing a “cognitive” approach to doing good over an “affective” one. The detachment isn’t slowly, laboriously thinking your way to acting compassionately as an ideal utilitarian solution–the danger here is the ease with which you can instead think your way to conveniently concluding this isn’t your problem to worry about. The key is neither a good (limbic) heart nor a frontal cortex that can reason you to the point of action. Instead it’s the case of things that have long since become implicit and automatic–being potty trained; riding a bike; telling the truth; helping someone in need.

[k8723] Yes, you don’t act because someone else’s pain is so painful–that’s a scenario that begs you to flee instead. But the detachment that should be aimed for doesn’t represent choosing a “cognitive” approach to doing good over an “affective” one. The detachment isn’t slowly, laboriously thinking your way to acting compassionately as an ideal utilitarian solution–the danger here is the ease with which you can instead think your way to conveniently concluding this isn’t your problem to worry about. The key is neither a good (limbic) heart nor a frontal cortex that can reason you to the point of action. Instead it’s the case of things that have long since become implicit and automatic–being potty trained; riding a bike; telling the truth; helping someone in need. Fifteen Metaphors We Kill By EXAMPLE 1 Stretching back at least to that faux pas about the golden calf at Mt.

[k8983] The key to evolution as an improviser rather than inventor is chapter 10’s concept of exaptation–some trait evolves for some purpose and is co-opted when it turns out to be useful for something else. And soon feathers are aiding flight, in addition to regulating body temperature, and the insula helps get us into heaven, in addition to purging our guts of toxins. The latter is a case of what has been called “neural reuse.”

[k9101] Something similar happened in South Africa, much of it promulgated by Nelson Mandela, a genius at appreciating sacred values. Mandela, while at Robben 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 mind-set.

[k9109] Instead the 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. While the general did not quite wind up as Mandela’s soul mate, and it is impossible to assess the importance of any single thing that Mandela said or did, Viljoen was stunned by Mandela’s use of Afrikaans and warm, chatty familiarity with Afrikaans culture. An act of true respect for sacred values. “Mandela wins over all who meet him,” he later said. And 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. When Mandela retired from his presidency in 1999, Viljoen gave a short, halting speech in Parliament praising Mandela . . . in the latter’s native language, Xhosa.

[k9568] Archaeologists do something impressive, reflecting disciplinary humility. When archaeologists excavate a site, they recognize that future archaeologists will be horrified at their primitive techniques, at the destructiveness of their excavating. Thus they often leave most of a site untouched to await their more skillful disciplinary descendants. For example, astonishingly, more than forty years after excavations began, less than 1 percent of the famed Qin dynasty terra-cotta army in China has been uncovered.

[k9605] But there is simply no place for the idea that punishment is a virtue. Our dopaminergic pathways will have to find their stimulation elsewhere. I sure don’t know how best to achieve that mind-set. But crucially, I sure do know we can do it–because we have before: Once people with epilepsy were virtuously punished for their intimacy with Lucifer. Now we mandate that if their seizures aren’t under control, they can’t drive. And the key point is that no one views such a driving ban as virtuous, pleasurable punishment, believing that a person with treatment-resistant seizures “deserves” to be banned from driving. Crowds of goitrous yahoos don’t excitedly mass to watch the epileptic’s driver’s license be publicly burned. We’ve successfully banished the notion of punishment in that realm. It may take centuries, but we can do the same in all our current arenas of punishment.

[k9633] Many who are viscerally opposed to this view charge that it is dehumanizing to frame damaged humans as broken machines. But as a final, crucial point, doing that is a hell of a lot more humane than demonizing and sermonizing them as sinners.

[k10561] The certainty with which we act now might seem ghastly not only to future generations but to our future selves as well.

[k10579] Finally, you don’t have to choose between being scientific and being compassionate.