Behave: The Biology of Humans at Our Best and Worst

by Robert M. Sapolsky

“Behave is the best detective story ever written, and the most important. If you’ve ever wondered why someone did something—good or bad, vicious or generous—you need to read this book. If you think you already know why people behave as they do, you need to read this book. In other words, everybody needs to read it. It should be available on prescription (side effects: chronic laughter; highly addictive). They should put Behave in hotel rooms instead of the Bible: the world would be a much better, wiser place.” —Kate Fox, author of Watching the English

To Mel Konner, who taught me. To John Newton, who inspired me. To Lisa, who saved me.

This book explores the biology of violence, aggression, and competition—the behaviors and the impulses behind them, the acts of individuals, groups, and states, and when these are bad or good things. It is a book about the ways in which humans harm one another. But it is also a book about the ways in which people do the opposite. What does biology teach us about cooperation, affiliation, reconciliation, empathy, and altruism?

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

This is my definition of courage.

cognition (defined by Princeton’s Jonathan Cohen as “the ability to orchestrate thought and action in accordance with internal goals”)?

The Obligatory Declaration of the Falseness of the Dichotomy Between Cognition and Emotion

dopamine is not about the happiness of reward. It’s about the happiness of pursuit of reward that has a decent chance of occurring.

A leading theory points to the plunging levels of progesterone as menses approaches and thus the loss of its anxiolytic and sedating effects.

"Anxiolytic" is unlikely to be ins most readers' vocabularies.

Moreover, there is the temptation to conclude that epigenetics explains “everything,” whatever that might be; most effects of childhood experience on adult outcomes probably don’t involve epigenetics and (stay tuned) most epigenetic changes are transient. Particularly strong criticisms come from molecular geneticists rather than behavioral scientists (who generally embrace the topic); some of the negativity from the former, I suspect, is fueled by the indignity of having to incorporate the likes of rat mothers licking their pups into their beautiful world of gene regulation.

As a molecular geneticist, I would be party to the "particualrly strong criticisms" mentioned, but not for the reason he gives. In fact, I doubt most molecular biologists have any problem to that so-called indignity. Rather, my problem would be the one he mentions a couple paragraphs further, which I note below.

But none of this is truly amazing. Because things must work these ways. While little in childhood determines an adult behavior, virtually everything in childhood changes propensities toward some adult behavior. Freud, Bowlby, Harlow, Meaney, from their differing perspectives, all make the same fundamental and once-revolutionary point: childhood matters. All that the likes of growth factors, on/off switches, and rates of myelination do is provide insights into the innards of that fact.

This is my basic problem with the idea that epigenetics "explains" everything, or even much of anything.

The DRD4 gene is super variable, coming in at least ten different flavors in humans.

I think this refers to alleles, not alternative splicing.

(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).

I once heard it summarized by a Southern studies scholar describing the weirdness of leaving the rural South to start grad school in a strange place, Cambridge, Massachusetts, where families would get together at Fourth of July picnics and no one would shoot each other.

Predictably, half of each conference on the subject consists of definitional squabbles.

A similar conclusion comes in the 2011 book The Better Angels of Our Nature: Why Violence Has Declined, by Harvard’s Steven Pinker.56 Cliché police be damned, you can’t mention this book without calling it “monumental.”

HGs gossip endlessly, and as studied by Polly Wiessner of the University of Utah, it’s mostly about the usual: norm violation by high-status individuals.77 People magazine around the campfire.

HG = hunter-gatherer.

Geographic evidence. To use Richard Dawkins’s suggestion for dealing with a fundamentalist insisting that all species emerged in their current forms from Noah’s ark—how come all thirty-seven species of lemurs that made landfall on Mt. Ararat in the Armenian highlands hiked over to Madagascar, none dying and leaving fossils in transit?

I’m a fairly solitary person—after all, I’ve spent a significant amount of my life studying a different species from my own, living alone in a tent in Africa.

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

religious wars, which are, to cite a quote generally attributed to Napoleon, “people killing each other over who has the better imaginary friend,”

definitive exploration of this is the 1995 book On Killing: The Psychological Cost of Learning to Kill in War and Society, by David Grossman, a professor of military science and retired U.S. Army colonel.

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.

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.

Genes aren’t about inevitabilities; they’re about potentials and vulnerabilities. And they don’t determine anything on their own. Gene/environment interactions are everywhere. Evolution is most consequential when altering regulation of genes, rather than genes themselves.

If you had to boil this book down to a single phrase, it would be “It’s complicated.”