Behave: The Biology of Humans at Our Best and Worst

by Robert M. Sapolsky

The motoric features of our behaviors are less important and challenging to understand than the meaning behind our muscles’ actions.

Chris would like this

In contrast to the SNS and the four Fs, the PNS is about calm, vegetative states. The SNS speeds up the heart; the PNS slows it down. The PNS promotes digestion; the SNS inhibits it (which makes sense—if you’re running for your life, avoiding being someone’s lunch, don’t waste energy digesting breakfast).

In PTSD sufferers the amygdala is overreactive to mildly fearful stimuli and is slow in calming down after being activated.13 Moreover, the amygdala expands in size with long-term PTSD.

Everyone knows that humans are innately afraid of snakes and spiders. But some people keep them as pets, give them cute names.* Instead of inevitable fear, we show “prepared learning”—learning to be afraid of snakes and spiders more readily than of pandas or beagles.

Me asf

Where do these “Ohhh, the tone isn’t scary anymore” neurons get inputs from? The frontal cortex. When we stop fearing something, it isn’t because some amygdaloid neurons have lost their excitability. We don’t passively forget that something is scary. We actively learn that it isn’t anymore.*

In other words, the default state is to trust, and what the amygdala does is learn vigilance and distrust.

Your heart does roughly the same thing whether you are in a murderous rage or having an orgasm. Again, the opposite of love is not hate, it’s indifference. —

the frontal cortex makes you do the harder thing when it’s the right thing to do.

There’s another circumstance where the frontal cortex is hypofunctional, producing similar behavioral manifestations—hypersexuality, outbursts of emotion, flamboyantly illogical acts.54 What disease is this? It isn’t. You’re dreaming. During REM sleep, when dreaming occurs, the frontal cortex goes off-line, and dream scriptwriters run wild. Moreover, if the frontal cortex is stimulated while people are dreaming, the dreams become less dreamlike, with more self-awareness. And there’s another nonpathological circumstance where the PFC silences, producing emotional tsunamis: during orgasm.

Concrete basis for harmony, nice

Briefly, the frontal cortex runs “as if” experiments of gut feelings—“How would I feel if this outcome occurred?”—and makes choices with the answer in mind. Damaging the vmPFC, thus removing limbic input to the PFC, eliminates gut feelings, making decisions harder.

As we saw, without the dlPFC, the metaphorical superego is gone, resulting in individuals who are now hyperaggressive, hypersexual ids. But without a vmPFC, behavior is inappropriate in a detached way. This is the person who, encountering someone after a long time, says, “Hello, I see you’ve put on some weight.” And when castigated later by their mortified spouse, they will say with calm puzzlement, “But it’s true.” The vmPFC is not the vestigial appendix of the frontal cortex, where emotion is something akin to appendicitis, inflaming a sensible brain. Instead it’s essential.64 It wouldn’t be if we had evolved into Vulcans. But as long as the world is filled with humans, evolution would never have made us that way.

One of the coolest synergies between philosophy and science i have ever read

Chapter 6 discusses experiments where a subject plays a game with two other people and is manipulated into feeling that she is being left out. This activates her amygdala, periaqueductal gray (that ancient brain region that helps process physical pain), anterior cingulate, and insula, an anatomical picture of anger, anxiety, pain, disgust, sadness. Soon afterward her PFC activates as rationalizations kick in—“This is just a stupid game; I have friends; my dog loves me.” And the amygdala et al. quiet down. And what if you do the same to someone whose frontal cortex is not fully functional? The amygdala is increasingly activated; the person feels increasingly distressed. What neurological disease is involved? None. This is a typical teenager. Finally,

Now—surprise!—the monkey presses the lever ten times and gets two raisins. Whoa: twenty units of dopamine are released. And as the monkey continues to get paychecks of two raisins, the size of the dopamine response returns to ten units. Now reward the monkey with only a single raisin, and dopamine levels decline. Why? This is our world of habituation, where nothing is ever as good as that first time.

Dopaminergic responses to reward, rather than being absolute, are relative to the reward value of alternative outcomes. In order to accommodate the pleasures of both mathematics and orgasms, the system must constantly rescale to accommodate the range of intensity offered by particular stimuli. The response to any reward must habituate with repetition, so that the system can respond over its full range to the next new thing.

What was an unexpected pleasure yesterday is what we feel entitled to today, and what won’t be enough tomorrow.

Remarkably, once that new scenario is learned, far more dopamine is released. Why? Because nothing fuels dopamine release like the “maybe” of intermittent reinforcement.95

iykyk bruhh

There’s a dualist temptation now to view his behavior as more “biological” or “organic” in some nebulous manner than if he had committed the same act with a normal PFC. However, the guy’s awful, impulsive act is equally “biological” with or without a PFC. The sole difference is that the workings of the PFC-less brain are easier to understand with our primitive research tools.

If people around you smell scared, your brain tilts toward concluding that you are too.

Metaphorically, the frontal cortex says, “Screw it. I’m tired and don’t feel like thinking about my fellow human.”

in circumstances where status is achieved through prosocial routes, the presence of women makes men more prosocial.

Thus, not only does the amygdala detect fearful faces, but it also biases us toward obtaining information about fearful faces.

Show subjects a picture of an object embedded in a complex background. Within seconds, people from collectivist cultures (e.g., China) tend to look more at, and remember better, the surrounding “contextual” information, while people from individualistic cultures (e.g., the United States) do the same with the focal object. Instruct subjects to focus on the domain that their culture doesn’t gravitate toward, and there’s frontal cortical activation—this is a difficult perceptual task. Thus, culture literally shapes how and where you look at the world.*43

the more experience a male had being aggressive prior to castration, the more aggression continues afterward. In other words, the less his being aggressive in the future requires testosterone and the more it’s a function of social learning.

a better question is whether differences in testosterone levels among individuals predict who will be aggressive. And among birds, fish, mammals, and especially other primates, the answer is generally no.

Testosterone boosts impulsivity and risk taking, making people do the easier thing when it’s the dumb-ass thing to do.

Lmfao

Testosterone did not create new social patterns of aggression; it exaggerated preexisting ones.

What the hormone makes you do depends on what counts as being studly.

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. 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.

Wowwwwww :v

Thus, oxytocin makes you more prosocial to people like you (i.e., your teammates) but spontaneously lousy to Others who are a threat. As emphasized by De Dreu, perhaps oxytocin evolved to enhance social competence to make us better at identifying who is an Us.

What is a social construct is medicalizing and pathologizing these shifts as “symptoms,” a “syndrome,” or “disorder.”

The core of psychological stress is loss of control and predictability.

Humans excel at stress-induced displacement aggression—consider how economic downturns increase rates of spousal and child abuse.

In a world in which status is awarded for the best of our behaviors, testosterone would be the most prosocial hormone in existence.

Oxytocin is not a universal luv hormone. It’s a parochial one.

Forming memories doesn’t require new synapses (let alone new branches or neurons); it requires the strengthening of preexisting synapses.1 What does “strengthening” mean? In circuitry terms, if neuron A synapses onto neuron B, it means that an action potential in neuron A more readily triggers one in neuron B. They are more tightly coupled; they “remember.” Translated into cellular terms, “strengthening” means that the wave of excitation in a dendritic spine spreads farther, getting closer to the distant axon hillock.

Hippocampal neurogenesis, for example, is enhanced by learning, exercise, estrogen, antidepressants, environmental enrichment, and brain injury* and inhibited by various stressors.

We’ve seen how in adults experience can alter the number of synapses and dendritic branches, remap circuitry, and stimulate neurogenesis.

Awfully structured sentence i stg

Rejection hurts adolescents more, producing that stronger need to fit in.25

This adolescent empathy frenzy can seem a bit much for adults. But when I see my best students in that state, I have the same thought—it used to be so much easier to be like that. My adult frontal cortex may enable whatever detached good I do. The trouble, of course, is how that same detachment makes it easy to decide that something is not my problem.

Ironically, it seems that the genetic program of human brain development has evolved to, as much as possible, free the frontal cortex from genes.

Here’s what not having ToM looks like. A two-year-old and an adult see a cookie placed in box A. The adult leaves, and the researcher switches the cookie to box B. Ask the child, “When that person comes back, where will he look for the cookie?” Box B—the child knows it’s there and thus everyone knows. Around age three or four the child can reason, “They’ll think it’s in A, even though I know it’s in B.” Shazam: ToM.

Humans understand logical operations between individuals earlier than between objects.

But because Carolee was the most wonderful teacher alive, ToM failed. Afterward I asked her, “Hey, why didn’t you tell everyone that Carolee is your teacher?” “Oh, everyone knows Carolee.” How could everyone not?

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. It also helps explain the imperviousness to negative feedback—why change your behavior if punishment doesn’t register?

“Every heroic act measures itself by its contempt of some external good.” Stage 6 reasoning can inspire. But it can also be insufferable, premised on “being good” and “being law abiding” as opposites. “To live outside the law, you must be honest,” wrote Bob Dylan.

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.

What majorly predicts a life of crime? Being born to a mother who, if she could, would have chosen that you not be. What’s the most basic thing provided by a mother? Knowing that she is happy that you exist.*26

they spent the first months, even years, of their lives without contact with another living being, before being placed in a social group.* Predictably, they’d be wrecks. Some would sit alone, clutching themselves, rocking “autistically.” Others would be markedly inappropriate in their hierarchical or sexual behaviors.

This is so upsetting :(

Behaviors were normal but occurred at the wrong time and place—say, giving subordination gestures to pipsqueaks half their size, threatening alphas they should cower before. Mothers and peers don’t teach the motoric features of fixed action patterns; those are hardwired. They teach when, where, and to whom—the appropriate context for those behaviors.