Behave: The Biology of Humans at Our Best and Worst

by Robert M. Sapolsky

Ultimately, forgiveness is usually about one thing—“This is for me, not for you.” Hatred is exhausting; forgiveness, or even just indifference, is freeing. To quote Booker T. Washington, “I shall allow no man to belittle my soul by making me hate him.” Belittle and distort and consume. Forgiveness seems to be at least somewhat good for your health—victims who show spontaneous forgiveness, or who have gone through forgiveness therapy (as opposed to “anger validation therapy”) show improvements in general health, cardiovascular function, and symptoms of depression, anxiety, and PTSD. Chapter 14 explored how compassion readily, perhaps inevitably, contains elements of self-interest. The compassionate granting of forgiveness epitomizes this.41

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.

Anyone who says that our worst behaviors are inevitable knows too little about primates, including us.

The war machines in combatant countries spewed the usual pseudospeciating propaganda. But in studying soldiers’ diaries and letters, Ashworth observed minimal hostility toward the enemy expressed by trench soldiers; the further from the front, the more hostility. In the words of one frontline soldier, quoted by Ashworth, “At home one abuses the enemy, and draws insulting caricatures. How tired I am of grotesque Kaisers. Out here, one can respect a brave, skillful, and resourceful enemy. They have people they love at home, they too have to endure mud, rain and steel.”

A key point of the previous chapter was that those in the future will look back on us and be appalled at what we did amid our scientific ignorance. A key challenge in this chapter is to recognize how likely we are to eventually look back at our current hatreds and find them mysterious.

The philosopher George Santayana provided us with an aphorism so wise that it has suffered the fate of becoming a cliché—“Those who cannot remember the past are condemned to repeat it.” In the context of this final chapter, we must turn Santayana on his head—those who do not remember the extraordinary truces of the World War I trenches, or who do not learn of Thompson, Colburn, and Andreotta, or of the reconciliative distances traveled by Abe and Fiske, Mandela and Viljoen, Hussein and Rabin, or of the stumbling, familiar moral frailties that Newton vanquished, or who do not recognize that science can teach us how to make events like these more likely—those who do not remember these are condemned to be less likely to repeat these reasons to hope.

As the single most important of them, virtually every scientific fact presented in this book concerns the average of what’s being measured. There is always variation, and it’s often the most interesting thing about a fact.

Childhood adversity can scar everything from our DNA to our cultures, and effects can be lifelong, even multigenerational. However, more adverse consequences can be reversed than used to be thought. But the longer you wait to intervene, the harder it will be.

Things that seem morally obvious and intuitive now weren’t necessarily so in the past; many started with nonconforming reasoning.

Repeatedly, biological factors (e.g., hormones) don’t so much cause a behavior as modulate and sensitize, lowering thresholds for environmental stimuli to cause it.

Genes have different effects in different environments; a hormone can make you nicer or crummier, depending on your values; we haven’t evolved to be “selfish” or “altruistic” or anything else—we’ve evolved to be particular ways in particular settings. Context, context, context.

Adolescence shows us that the most interesting part of the brain evolved to be shaped minimally by genes and maximally by experience; that’s how we learn—context, context, context.

Often we’re more about the anticipation and pursuit of pleasure than about the experience of it.

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.

We implicitly divide the world into Us and Them, and prefer the former. We are easily manipulated, even subliminally and within seconds, as to who counts as each.

We aren’t chimps, and we aren’t bonobos. We’re not a classic pair-bonding species or a tournament species. We’ve evolved to be somewhere in between in these and other categories that are clear-cut in other animals. It makes us a much more malleable and resilient species. It also makes our social ...

Many of our best moments of morality and compassion have roots far deeper and older than being mere products of human civilization.

Be dubious about someone who suggests that other types of people are like little crawly, infectious things.

It’s not great if someone believes it’s okay for people to do some horrible, damaging act. But more of the world’s misery arises from people who, of course, oppose that horrible act . . . but cite some particular circumstances that should make them exceptions. The road to hell is paved with rationalization.

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

Neither the capacity for fancy, rarefied moral reasoning nor for feeling great empathy necessarily translates into actually doing somethi...

People kill and are willing to be killed for symbolic sacred values. Negotiations can make peace with Them; understanding and respecting the intensity of ...

Our worst behaviors, ones we condemn and punish, are the products of our biology. But don’t forget that the same applies to our best behaviors.

Individuals no more exceptional than the rest of us provide stunning examples of our finest moments as humans.

If you had to boil this book down to a single phrase, it would be “It’s complicated.” Nothing seems to cause anything; instead everything just modulates something else. Scientists keep saying, “We used to think X, but now we realize that . . .” Fixing one thing often messes up ten more, as the law of unintended consequences reigns. On any big, important issue it seems like 51 percent of the scientific studies conclude one thing, and 49 percent conclude the opposite. And so on. Eventually it can seem hopeless that you can actually fix something, can make things better. But we have no choice but to try. And if you are reading this, you are probably ideally suited to do so. You’ve amply proven you have intellectual tenacity. You probably also have running water, a home, adequate calories, and low odds of festering with a bad parasitic disease. You probably don’t have to worry about Ebola virus, warlords, or being invisible in your world. And you’ve been educated. In other words, you’re one of the lucky humans. So try.

The naturalist Edward O. Wilson, one of the most influential thinkers of our time, has found himself at the center of fiery controversies related to the evolution of human social behavior (discussed in chapter 10). An elegant and graceful man, he has written about those disputes and those who have most strongly opposed him—“Without a trace of irony I can say I have been blessed with brilliant enemies. I owe them a great debt, because they redoubled my energies and drove me in new directions.”