Robert Sapolsky is breathing hard, partly from the sheer physical exertion of sliding on his back into the cavern where a tranquilized baboon has dragged a dying impala, partly from the anxiety of not knowing if he is going to have to tangle with a drugged 70-pound beast with three-inch canine teeth. Once inside the tiny cave, he is relieved to see that the baboon he darted is out cold. But from outside the cave he hears the angry screams of other baboons who want that impala, who are willing to fight and even kill to get it. These shrieking primates don’t know what’s happening in the cave and are hesitant to enter, but they won’t be for long. Sapolsky sees shadows flick across the light from the cave entrance; when the entrance goes dark he shouts, temporarily scaring the intruders away. He has to work fast.
Unsheathing a hypodermic needle, he is reaching to take a quick blood sample from the baboon when—whack!—a blow slices his forehead and knocks him backward. The impala is mortally wounded from the jagged hole in its gut, but still alive enough to make itself noticed. The panicked animal’s sharp hooves fly about the enclosed space in a blur, and Sapolsky realizes he is “about to be killed by Bambi.”
He leaps on the impala, struggles with it (later he thinks he must have strangled it) and then the impala is dead and the baboons outside are venturing more deeply into the cave. The sweaty, bloody Sapolsky has no option but to push the deadweight of the beast toward the cave entrance, straining to bulldoze the impala across the dirt until soon the offering is sliding faster than he’s pushing and is then whisked away by furry hands. Sapolsky gets the baboon’s blood sample and waits until the screams of fighting and feasting die down outside.
Thus ends what the Stanford neurobiologist calls his worst darting ever. But in the best of circumstances, darting wild and wily baboons with a blowgun is not easy, “even with a college education,” Sapolsky says. More than a quarter of a century ago he fulfilled a childhood dream by “joining a troop of baboons.” Since then he has made an annual pilgrimage to the Kenyan savanna to study the same group of primates, most years living alone for three months in a pup tent, sustained by little but tins of Taiwanese mackerel in tomato sauce and the desire to understand how stress affects the health and well-being of social animals like baboons—and humans.
His work on the savanna, supplemented by the laboratory work he does at Stanford, has led to a new understanding of how the social slights and struggles of everyday life can raise stress hormone levels, and how chronically elevated stress can contribute to disease (see sidebar). He has received a number of awards for his scientific advances, including a MacArthur “genius” grant in 1987.
Sapolsky is well-known around campus for his fascinating lectures in human behavioral biology. To the public at large, he is best known for three books: Why Zebras Don’t Get Ulcers (1994), The Trouble with Testosterone (1997) and A Primate’s Memoir (2001). The earlier books concentrate on his scientific work, but A Primate’s Memoir is a more personal look at his life in Africa, introducing us equally to the baboons and the human primates he encounters. As with most of his writing, the book is very funny. New York Times reviewer Patricia Leigh Brown called Sapolsky a cross between Jane Goodall and a Borscht Belt comedian, but most of his stories are closer to Woody Allen’s than Henny Youngman’s—incisive (and sometimes tragic) comedies of manners, topsy-turvy struggles across hierarchical lines for power and romance.
In most of these stories, Sapolsky is happy to use the time-honored narrative device of playing the buffoon: the rube who gets conned repeatedly the first day in Nairobi, the guy who year after year makes the nauseating mistake of stocking mackerel as his sole protein source on the savanna because he is in a rush to get there. He compares himself to a favorite baboon in the troop, Benjamin, who has “beserko” hair, stumbles over his feet and always manages to sit on the stinging ants.
Sapolsky himself has cascading hair and a full beard, which sometimes gives him a resemblance to Tom Hanks as a third-year castaway. In person, he is pleasant, soft-spoken and self-deprecating, someone you might easily imagine living happily alone in a tent in Africa. Watch him in action, however, or read between the lines about what he actually does in the field, and you get a completely different picture.
Whether you see him tearing up the turf around campus in pick-up games of soccer (at which he professes to be “not very good”) or hunting baboons on the savanna with a blowgun, you get the image of a man who exudes adrenaline and has a reservoir of intensity deep enough to spin the turbines at Hoover Dam. Here is a man who took a side trip to Uganda in 1979 just to see the fall of Idi Amin; he spent a night under a truck to avoid falling artillery shells. About that experience Sapolsky writes: “In a weird way it was cleansing to have those moments of sheer absolute terror and, when the shelling stopped, to feel the relief.”
His parents probably never imagined he would get himself into such a situation. Sapolsky, however, had his own plans. Born to Russian immigrants in Brooklyn, N.Y., he used to beg them to take him again and again to the Museum of Natural History, where he yearned to crawl into the African dioramas and live there. As an Orthodox Jewish kid “with no proclivities toward athletics or gang violence,” Sapolsky spent a lot of time reading and imagining living with silverback gorillas. By age 12, he was writing fan letters to primatologists; by high school, he was reading textbooks on the subject and teaching himself Swahili.
As a Harvard undergraduate, however, he began to focus on scientific questions that could not be answered by studying mountain gorillas. Sapolsky wanted to know how and why stress is bad for the body and, perhaps more important, why some people resist stress better than others. That is why, in 1977, he began studying neuroendocrinology as a graduate student at Rockefeller University, and why the following summer, at age 21, he joined the baboon troop as “a young transfer male.”
Baboons—singular-looking primates with a wild hairdo, close-set eyes, a long muzzle and permanent leathery pads covering their rear ends—are great subjects for studying social stress, Sapolsky says, because they live in large, complex groups. Those who inhabit the open Serengeti Plain find plenty of food and few predators. They therefore must devote only about four hours each day to feeding themselves and have a half-dozen hours of daylight to make life miserable for each other. “Baboons, like humans, have the luxury of making themselves sick with purely psychological stress,” Sapolsky says.
To measure the effects of social stress, Sapolsky observes the baboons’ interactions, then takes blood samples to record how stress-hormone levels correlate with various behaviors. Tranquilizing the baboons to draw blood is more difficult than it sounds. Sapolsky uses a blowgun—a metal and plastic tube that he loads with an anesthetic dart, aims and blows through—because, he says, it is more mechanically reliable than an air rifle. Its range is about 30 feet, barring wind, so he has to get quite close to the selected target. (Sapolsky darts only males, because females are most often pregnant or caring for their young.) The darting must take place at the same time each day to allow for daily cycles in stress hormones, and the subject mustn’t know what’s coming because that in itself would raise stress levels.
As the baboons gained experience with his technique, they learned to distinguish between the sounds of Sapolsky inhaling to sneeze or inhaling to blow a dart. He has to resort to all sorts of subterfuges to keep them off their game: borrowing other people’s vehicles, getting others to drive him around, even wearing Halloween masks. Once an animal is darted, Sapolsky follows him until he’s asleep. Then he covers the animal with a burlap sack to keep the other baboons from going crazy—as humans would if we saw one of our own abducted by an alien—and carries him away to take a blood sample.
“There’s nothing I enjoy more in the world,” Sapolsky says of darting. He loves stalking the animals, sneaking up close enough to blow a dart into them and pursuing them afterward until they feel drowsy and drop off to sleep. Sapolsky admits to savoring a delicious irony: he is a liberal who opposes guns and hunting but knows intimately the joys of the hunt.
After a time it became clear to Sapolsky that the baboons saw him as one of the troop, albeit the lowest, most pathetic member. There is a certain look, a certain set of signals, that one baboon will give another when he is about to be mauled by a more dominant baboon. That look tells the bystander, “Hey, can you help me out here?” Occasionally, when no other potential saviors were around, a desperate baboon would give Sapolsky such a signal. “I think they were hoping I’d run the other baboon over with my jeep,” he says.
The hirsute scientist was also regarded as an oddity by the local Masai, the fierce, spear-carrying warriors of East Africa who live mostly by drinking milk and blood culled from the cattle they herd. “I think the Masai see me as somehow herding the baboons,” Sapolsky says. “Taking blood they can understand more. They don’t think I drink the blood, but I imagine they think I make my living off it, that I use it in some shamanistic fashion.” Which, he admits, is true in a way. The Masai are generally friendly with Sapolsky, although two of them once got wildly upset and pointed their spears at him when he kidded them that a baboon sleeping in his arms was his brother.
Closer to home, some colleagues have taken jabs at his popular writing. “Everyone at Stanford has been very supportive, but people like [biological sciences professor] Paul Ehrlich have warned me that I risk being saganized,” Sapolsky says, referring to the dismissive treatment astronomer Carl Sagan received from the scientific community after he became famous for his television appearances and his writing. “Some scientists seem to think if you have time to write about your work in a popular, humorous way, you can’t do serious science.”
Ehrlich himself chalks that response up to the “ancient training” of scientists. “They know that the public needs to understand science; but when someone really smart who can really write comes along, many of them say, ‘Shoemaker, stick to your last.’”
Others have criticized Sapolsky for anthropomorphizing the behavior of the baboons. For instance, instead of assigning his subjects numbers, Sapolsky gave the baboons Old Testament names, like Uriah, Bathsheba and Nebuchadnezzar. He also writes about his troop for the public in a very colloquial way. But Sapolsky categorically rejects the idea that he is assigning human attributes to baboons. Although he admits to some obvious exaggerations for humor (“. . . no doubt Saul was beginning to contemplate the building of grand commemorative cathedrals”), for the most part, he says, he is “primatizing human behavior,” writing about qualities we share with them as fellow primates.
Sapolsky sees applications of primatology in everyday life—for example, in the struggle for dominance at faculty meetings. His strategies for academic survival borrow from the baboons’ diplomatic skills: “I’ve learned to make coalitions and occasionally stick my rear in the air in a subordinate manner,” Sapolsky says.
He has also taken to heart his finding that the healthiest, least stressed baboons have strong social connections. While he was not a complete hermit in Africa, Sapolsky typically spends a lot of time alone. “I have always been able to be with people, and to enjoy it,” he says. “But I fairly regularly need to be alone for long periods, and seem to have a much higher threshold than most people for really extended periods alone.”
Sapolsky began to spend less time alone after he met his future wife, Lisa. That was in the mid-1980s, while he was doing postdoctoral work at the Salk Institute. “I can tell you from my own blood pressure data that this is a much saner way of living,” Sapolsky says. When he first took Lisa with him to his camp in Kenya, he also saw himself in a different light. As local kids and adults kept stopping by to socialize—something they had never done before—Sapolsky realized that on his solo visits he must have seemed like a “forbidding weirdo.”
More recently he and his wife have strengthened their social network by having two children, Benjamin, 4, and Rachel, 2. But here his knowledge of baboons has been surprisingly little help. “When I became a father I thought, ‘This is going to be a primatology blowout; I’m going to be great at this.’ The truth is I was lousy; I had to learn how to be a father,” Sapolsky says. “Somewhere around the time that an infant finds a stuffed animal popping up to be funny, that just struck me—you’re in a whole different territory here.” He also notes that the emotionally engulfing experience of parenthood is very different from being a detached observer. “There is an element of chaos, an inability to pull yourself back and turn the whole thing into a lecture for a class.”
Now, with an absorbing social network at home (and a close-knit group in his laboratory at Stanford), Sapolsky spends only about 21 days a year with the baboons instead of three months. And when he is in Africa, he is much more careful than before about getting smeared by a buffalo or stomped by an elephant or shot by an AK-47. Probably more often than not there is some member of his domestic social unit giving him a look that says, “Can you help me out here?”
It looks as though Robert Sapolsky has settled into a human troop at last.
Christopher Vaughan is a science writer in Menlo Park.