Robert Sapolsky

Based on Wikipedia: Robert Sapolsky

The Night a Teenager Figured Out the Universe

One night, a teenage boy in Brooklyn woke up at two in the morning with a revelation. He had been raised Orthodox Jewish, attending synagogue regularly, learning the ancient texts. But something had been nagging at him—a story from Exodus about Pharaoh and the Hebrew slaves.

In that story, God repeatedly "hardens Pharaoh's heart," making the Egyptian ruler refuse to free the Israelites. This creates a strange paradox: God punishes Pharaoh for decisions that God himself caused Pharaoh to make. The boy lay there in the dark, turning this over in his mind, and suddenly it clicked.

"Oh, I get it," he said to himself. "There is no god and there's no free will. The universe is this big, empty, indifferent place."

That teenager was Robert Sapolsky. And he would spend the next fifty years becoming one of the world's foremost experts on why humans do what they do—armed with the conviction that none of us are really choosing anything at all.

From Brooklyn to the Baboons

Robert Morris Sapolsky was born on April 6, 1957, to Soviet immigrants who had made their way to Brooklyn. His father, Thomas, was an architect with a specialty in restaurant renovation—he redesigned Lüchow's and Lundy's, two legendary New York dining establishments. But young Robert had zero interest in architecture or restaurants.

He was obsessed with gorillas.

As a child, Robert spent his free time reading everything he could find about silverback gorillas, imagining what it would be like to live among them. By the age of twelve, he was writing fan letters to primatologists—the scientists who study primates. This was not normal preteen behavior in 1969 Brooklyn, but Sapolsky was not a normal preteen.

At John Dewey High School, while his classmates were presumably doing whatever teenagers did in the early 1970s, Sapolsky was teaching himself Swahili. Why Swahili? Because that's what you speak in East Africa. And East Africa is where the primates live.

The Young Primate Studies Primates

In 1978, Sapolsky graduated summa cum laude—the highest honors—from Harvard University with a degree in biological anthropology. He immediately did what he had been dreaming about since childhood: he went to Kenya to study baboons in the wild.

Then things got interesting in the way that only happens when you're twenty-one years old and think you're invincible.

War broke out in the neighboring countries of Uganda and Tanzania. The Ugandan dictator Idi Amin had invaded Tanzania, and Tanzania was fighting back. Most sensible people would stay far away from an active war zone. Sapolsky decided to witness it up close.

"I was twenty-one and wanted adventure," he later explained. "I was behaving like a late-adolescent male primate."

This is a very Sapolsky thing to say—explaining his own reckless behavior through the lens of primate biology. He traveled to Uganda's capital, Kampala, then to the border with Zaire (now the Democratic Republic of the Congo), then back to Kampala again. He was there on April 10th and 11th of 1979 when the Tanzanian army and their Ugandan rebel allies conquered the capital.

Having satisfied his appetite for danger, Sapolsky returned to New York and earned his doctorate in neuroendocrinology at Rockefeller University, working in the lab of Bruce McEwen. Neuroendocrinology is the study of how hormones interact with the brain—a field that would become central to everything Sapolsky does.

Twenty-Five Summers with the Same Baboons

After that initial year and a half in Africa, Sapolsky didn't simply move on to laboratory work and academic papers. He went back. Every single summer, for twenty-five consecutive years, he returned to Kenya to observe the same group of baboons.

Think about that commitment. From the late 1970s to the early 1990s, and beyond, Sapolsky spent approximately four months each year sitting in the African savanna, watching baboons for eight to ten hours a day. He recorded their behaviors, tracked their relationships, and measured their stress hormones.

Why baboons? Because they're remarkably like us, at least in the ways that matter for studying stress.

Baboons live in complex social hierarchies. They form friendships and rivalries. They experience jealousy, ambition, and anxiety. And unlike many animals that face constant threats from predators or struggle to find food, baboons in the wild have relatively easy lives in terms of basic survival. They spend only about four hours a day foraging.

This means baboons have free time. And like humans with too much free time, they use it to make each other miserable. They scheme, they bully, they stress each other out through pure social drama.

Sound familiar?

The Science of Stress

Sapolsky's research has centered on one big question: what does stress do to us?

The short answer is: nothing good, at least when the stress is chronic.

When you encounter a threat—a lion charging at you, say—your body releases hormones called glucocorticoids. The most famous of these is cortisol. These hormones do amazing things in an emergency: they increase your heart rate, sharpen your focus, and flood your muscles with energy. They suppress non-essential systems like digestion and immune function. After all, there's no point fighting off a cold if you're about to be eaten.

This is called the stress response, and it can save your life.

The problem is that humans—and baboons—have evolved the ability to trigger this response through pure thought. We don't need an actual lion. We can stress ourselves out by imagining future problems, replaying past humiliations, or simply contemplating our place in the social hierarchy.

When stress becomes chronic, when those glucocorticoids keep pumping day after day, the results are devastating. Memory problems. Weakened immune systems. Cardiovascular disease. Depression. The very neurons in your brain start to degenerate.

This is why, as Sapolsky famously titled one of his books, zebras don't get ulcers. A zebra runs from a lion, escapes, and then goes back to grazing peacefully. The stress response turns on, does its job, and turns off. Humans, on the other hand, can give themselves ulcers by worrying about their mortgage payments or what their coworkers think of them.

Rank Has Its Privileges (and Its Costs)

One of Sapolsky's most important findings involves the relationship between social status and stress. You might assume that being at the top of a hierarchy would be maximally stressful—all that responsibility, all those challengers. The reality is more nuanced.

In stable hierarchies, dominant individuals actually have lower levels of stress hormones. They have more control over their environment, more predictability in their lives, and more access to social support. The subordinates, meanwhile, experience chronic stress from constant harassment and uncertainty.

But here's the twist: in unstable hierarchies, where the social order is constantly being contested, even the dominant individuals show elevated stress. They're always looking over their shoulders, always fighting to maintain their position.

This research has profound implications for human health. Studies of human workplaces—most famously the Whitehall Studies of British civil servants—have shown similar patterns. People in lower-ranking positions tend to have worse health outcomes, even when you control for factors like income and access to healthcare. The stress of low status appears to be directly toxic to the body.

The Professor at Stanford

Today, Sapolsky holds the John A. and Cynthia Fry Gunn Professorship at Stanford University, with joint appointments in biological sciences, neurology and neurological sciences, and neurosurgery. He's also a research associate with the National Museums of Kenya, maintaining his connection to those African baboons.

His current research has expanded to include gene therapy—specifically, techniques for protecting vulnerable neurons from the damaging effects of stress hormones. The goal is to find ways to strengthen brain cells against the glucocorticoid assault that comes with chronic stress, potentially offering treatments for conditions like depression and neurodegenerative diseases.

Sapolsky has also become deeply interested in some unexpected topics. He writes about the relationship between religious rituals and obsessive-compulsive behavior, noting the striking similarities between the two. He's explored how schizotypal disorders—conditions involving unusual perceptions and magical thinking—may have played a role in the emergence of shamanism and the major Western religions. And he's written about neurological impairment and the insanity defense in American law.

The Science Communicator

What sets Sapolsky apart from many academics is his gift for explaining complex science to regular people. His books have reached enormous audiences. "Why Zebras Don't Get Ulcers" became a classic of popular science writing. "A Primate's Memoir" combined his scientific observations with adventure stories from his time in Africa. "Behave: The Biology of Humans at Our Best and Worst," published in 2017, was an ambitious attempt to explain human behavior from multiple biological perspectives—from the moment before an action occurs all the way back through evolutionary time.

His lectures have also found huge audiences. His Stanford course on human behavioral biology is available on YouTube, where millions of people have watched this bearded professor pace energetically across a stage, explaining neuroscience with infectious enthusiasm. He's appeared on podcasts like Radiolab and The Joe Rogan Experience, and gave a TED Talk in 2017.

His speaking style is distinctive: rapid-fire delivery, frequent jokes, and a willingness to say surprising things. He'll make a point about hormone receptors and then illustrate it with a story about baboon politics that sounds like a soap opera.

The Case Against Free Will

Remember that teenager who woke up at two in the morning convinced that there was no free will? He never changed his mind.

In 2023, Sapolsky published "Determined: A Science of Life Without Free Will," his most controversial book. In it, he argues—vigorously—that free will is an illusion. Every action we take, every decision we make, is the inevitable result of our neurobiology, our hormones, our childhood experiences, and our circumstances. We feel like we're choosing, but we're not.

This is not a casual opinion for Sapolsky. It's the logical conclusion of everything he's studied for fifty years. If you understand that behavior emerges from brain activity, and brain activity is shaped by genes and experience and current brain chemistry, then where exactly does "free choice" enter the picture?

The implications are profound. If no one truly chooses their actions, then our entire system of moral responsibility comes into question. Why punish criminals if they couldn't have done otherwise? Why take credit for our achievements if we didn't really earn them?

Sapolsky doesn't shy away from these questions. He argues that understanding the absence of free will should lead us toward more compassion, not less responsibility. We can still protect society from dangerous people, but we should do so without the satisfying cruelty of retribution.

Not everyone agrees, of course. The free will debate has raged among philosophers for centuries, and Sapolsky's confident determinism strikes many as too reductive. But he makes his case with the full weight of neuroscience behind him.

The Personal Alongside the Scientific

In "Determined," Sapolsky did something unusual for a scientist: he wrote openly about his own struggles with depression. He described what it feels like to live with the condition—the weight of it, the way it distorts everything—while also noting the relief that medication has provided.

This personal disclosure fits with his philosophy. If behavior emerges from brain chemistry, then depression is not a moral failing or a weakness of character. It's a biological condition, as real as diabetes or heart disease. There's no shame in treating it chemically, any more than there would be shame in taking insulin.

Sapolsky is married to Lisa Sapolsky, a neuropsychologist. They have two children. In 2024, he launched something called Father-Offspring Interviews on YouTube and Spotify, featuring conversations with his daughter Rachel. The man who has spent his career studying primate family dynamics is now creating content about his own.

Awards and Recognition

The scientific establishment has recognized Sapolsky's contributions extensively. In 1987, he received a MacArthur Fellowship—the so-called "genius grant" that provides recipients with $500,000 to pursue their work without strings attached. He's also received an Alfred P. Sloan Fellowship, the Klingenstein Fellowship in Neuroscience, and the National Science Foundation Presidential Young Investigator Award.

Various scientific societies have honored him as Young Investigator of the Year: the Society for Neuroscience, the International Society for Psychoneuroendocrinology, and the Biological Psychiatry Society. In 2007, the American Association for the Advancement of Science gave him the John P. McGovern Award for Behavioral Science. The following year, Wonderfest awarded him the Carl Sagan Prize for Science Popularization—fitting recognition for someone who has brought complex science to such wide audiences.

He's also been embraced by the secular community. The Freedom From Religion Foundation gave him the Emperor Has No Clothes Award in 2002 and later named him to their Honorary Board. In his acceptance speech, he was characteristically direct about his journey from Orthodox Judaism to atheism, describing it as "one of the defining actions in my life."

The Big Picture

What makes Sapolsky's work so compelling is its scope. He's not just a lab scientist studying neurons in isolation, nor just a field researcher watching animals from a distance. He integrates everything—neuroscience, endocrinology, evolutionary biology, psychology, anthropology—into a unified picture of why living things behave as they do.

His work suggests that we are, in fundamental ways, still primates. Our stress responses evolved millions of years ago for a world of physical dangers, and they misfire constantly in our modern world of psychological threats. Our social hierarchies shape our health in ways we're only beginning to understand. Our decisions emerge from biological processes that we don't control and barely comprehend.

For some people, this is a depressing message. If we're just sophisticated apes, running on hormones and neural circuits, where's the meaning? Where's the transcendence?

Sapolsky would probably say that meaning is something we create, not something we discover. And understanding the biology doesn't make the experience less real. The joy you feel is still joy, even if you can trace it to dopamine and serotonin. The love you have for your family is still love, even if it evolved because attachment increased survival and reproduction.

And perhaps there's something freeing in the deterministic view. If your failures weren't really your fault—if you couldn't have done otherwise—then maybe you can stop punishing yourself. If other people's bad behavior emerged inevitably from their circumstances, maybe you can find compassion instead of rage.

At two in the morning, a teenager in Brooklyn decided the universe was big, empty, and indifferent. He's spent his life since then trying to understand it anyway. And in doing so, he's helped millions of people understand themselves a little better—which might be the most meaningful thing a primate can do.