Chapter 1: The Baboons: The Generations of Israel I joined the baboon troop during my twenty-first year. I had never planned to become a savanna baboon when I grew up; instead, I had always assumed I would become a mountain gorilla. As a child in New York, I endlessly begged and cajoled my mother into taking me to the Museum of Natural History, where I would spend hours looking at the African dioramas, wishing to live in one. Racing effortlessly across the grasslands as a zebra certainly had its appeal, and on some occasions, I could conceive of overcoming my childhood endomorphism and would aspire to giraffehood. During one period, I became enthused with the collectivist utopian rants of my elderly communist relatives and decided that I would someday grow up to be a social insect. A worker ant, of course. I made the miscalculation of putting this scheme into an elementary-school writing assignment about my plan for life, resulting in a worried note from the teacher to my mother. Yet, whenever I wandered the Africa halls in the museum, I would invariably return to the mountain gorilla diorama.

Something primal had clicked the first time I stood in front of it. My grandfathers had died long before I was born. They were mythically distant enough that I would not be able to pick either out in a picture. Amid this grandfatherly vacuum, I decided that a real-life version of the massive, sheltering silverback male gorilla stuffed in the glass case would be a good substitute. A mountainous African rain forest amid a group of gorillas began to seem like the greatest refuge imaginable. By age twelve, I was writing fan letters to primatologists. By fourteen, I was reading textbooks on the subject. Throughout high school, I finagled jobs in a primate lab at a medical school and, finally, sojourning to Mecca itself, volunteered in the primate wing of the museum.

I even forced the chairman of my high school language department to find me a self-paced course in Swahili, in preparation for the fieldwork I planned to do in Africa. Eventually, I went off to college to study with one of the deans of primatology. Everything seemed to be falling into place. But in college, some of my research interests shifted and I became focused on scientific questions that could not be answered with gorillas. I would need to study a species that lived out in the open in the grasslands, with a different type of social organization, a species that was not endangered. Savanna baboons, who had struck no particular chord in me before, became the logical species to study. You make compromises in life; not every kid can grow up to become president or a baseball star or a mountain gorilla. So I made plans to join the baboon troop.

I joined the troop in the last year of the reign of Solomon. In those days, the other central members of the troop were Leah, Devorah, Aaron, Isaac, Naomi, and Rachel. I didn''t plan beforehand to give the baboons Old Testament names. It just happened. A new adult male, leaving the troop he grew up in, would transfer into the troop, and during the few weeks when he''d vacillate about joining permanently, I would hesitate about giving him a name. I''d just refer to him in my notes as the new adult transfer, or NAT, or Nat, or, by the time he decided to stay forever, Nathanial. Adam was first known as ATM, for adult transfer male. The small kid who was first abbreviated as the SML kid then turned into Samuel on me.

At that point I just gave up and started handing out the prophets and matriarchs and judges left and right. I would still occasionally stick with a purely descriptive name -- Gums or Limp, for example. And I was way too insecure in my science to publish technical papers using these names -- everyone got a number then. But the rest of the time, I wallowed in biblical names. I have always liked Old Testament names, but I would hesitate to inflict Obadiah or Ezekial on a child of mine, so I ran wild with the sixty baboons in the troop. Plus, clearly, I was still irritated by the years I spent toting my Time-Life books on evolution to show my Hebrew school teachers, having them blanch at such sacrilege and tell me to put them away; it felt like a pleasing revenge to hand out the names of the patriarchs to a bunch of baboons on the African plains. And, with some sort of perversity that I suspect powers a lot of what primatologists do, I couldn''t wait for the inevitable day that I could record in my field notebook that Nebuchanezzar and Naomi were off screwing in the bushes. What I wanted to study was stress-related disease and its relationship to behavior.

Sixty years ago, a scientist named Selye discovered that your emotional life can affect your health. It struck the mainstream doctors as ludicrous -- people were perfectly accustomed to the idea of viruses or bacteria or carcinogens or whatnot getting you sick, but your emotions? Selye found that if you got rats upset in all sorts of purely psychological ways, they got sick. They got ulcers, their immune systems collapsed, their reproduction went to hell, they got high blood pressure. We know now exactly what was happening -- this was the discovery of stress-related disease. Selye showed that stress was what you were undergoing when emotional or physical disturbances threw your body''s balance out of whack. And if it went on for too long, you got sick. That last piece has been hammered home with a vengeance -- stress makes all sorts of things in the body go bad, and in the years since Selye, people have documented numerous diseases that can be worsened by stress. Adult onset diabetes, muscle atrophy, high blood pressure and atherosclerosis, arrested growth, impotency, amenorrhea, depression, decalcification of bones.

You name it. In my laboratory work, I was studying how, on top of all that, stress can kill certain brain cells. It seemed a miracle that any of us survived. But clearly we did. I decided that, in addition to my laboratory work on neurons, I wanted to study the optimistic side of it -- how come some of us are more resistant to stress than others? Why are some bodies and some psyches better at coping? Does it have something to do with your rank in society? If you have lots of relatives, if you hang out with friends? If you play with kids? If you sulk when you''re upset about something or if you find someone else to take it out on? I decided to go study this in wild baboons. They were perfect for it. Baboons live in big, complex social groups, and the population I went to study lived like kings. Great ecosystem, the Serengeti.

Grass and trees and animals forever, Marlin Perkins country. The baboons work maybe four hours a day to feed themselves; hardly anyone is likely to eat them. Basically, baboons have about a half dozen solid hours of sunlight a day to devote to being rotten to each other. Just like our society -- few of us are getting hypertensive from physical stressors, none of us are worrying about famines or locust plagues or the ax fight we''re going to have with the boss out in the parking lot at five o''clock. We live well enough to have the luxury to get ourselves sick with purely social, psychological stress. Just like these baboons. So I would go out and study the behavior of baboons, see who was doing what with whom -- fights, trysts and friendships, alliances and dalliances. Then I would dart them, anesthetize them, see how their bodies were doing -- blood pressure, cholesterol levels, rate of wound healing, levels of stress hormones.

What would individual differences in behavior and psychological patterns have to do with the individual differences in how their bodies were working? I wound up studying only the males. You wouldn''t want to anesthetize females when they were pregnant, or when they had a dependent nursing kid, and that''s most of the time for most of the females. Thus, I settled in with the males and planned to get to know them very well. It was 1978; John Travolta was the most important human alive, white suits were sweeping our proud nation, and Solomon was in the final year of his rule. Solomon was good and wise and just. Actually, that''s nonsense, but I was an impressionable young transfer male at the time. Nevertheless, he was a pretty imposing baboon. For years, the anthropology textbooks had been having a love affair with savanna baboons and their top-ranking male, the alpha male.

According to the books, the baboons were complex social primates living in open grasslands; they had organized hunts, a hierarchical rank system, and at their core was the alpha male. He led the troop to food, spearheaded the hunts, defended against predators, kept the females in line, changed the lightbulbs, fixed the car, blah blah blah. Just like our human ancestors, the textbooks ached to say, and sometimes even did. Most of that turned out to be wrong, naturally. The hunts for food were disorganized free-for-alls. Furthermore, the alpha male couldn''t lead the troop to food during a crisis, as he wouldn''t know where to go. The males transferred into the troops as adolescents, while the females spent their whole lives in the same troop. Thus, it would be the old females who remembered the grove of olive trees past the fourth hill.

When predators attacked, the alpha male would be in the thick of it, defending an infant. But only if he was absolutely certain that it was his kid who was at risk of becoming someone''s dinner. Otherwise, he had the highest, safest spot in the tree to watch the action. So much for Robert Ardrey and 1960s anthropology. Nevertheless, within the small, parochial, self-interested, unreflective, petty world of male baboons, being alpha was hot stuff. You might not really be the troop leader, but you got to do about half the matings, sit in.