The Nature of the Beast

Photo: Rod Searcey

He's a leading neurobiologist and an expert on the habits of baboons--so you expect Robert Sapolsky to know his stuff. The surprise is that he's also a fine and funny writer with more than science on his mind.

In a new collection of essays, The Trouble with Testosterone and Other Essays on the Biology of the Human Predicament (Scribners, 1997; $23), the Stanford professor of biology uses science as a prism through which to view life, death, transition and loss. The result is a book that makes you think and laugh on just about every page.

With a field scientist's habit of exact observation and a journalist's knack for storytelling, Sapolsky takes on subjects ranging from the physiological effects of overachievement to the influence of mental illness on the development of major religions. He marshals knowledge from a wide array of disciplines--evolutionary and classical psychology, neurobiology, primatology and pop culture (he admits to a fascination with O.J. and devotes a whole essay to alleged Unabomber Ted Kaczynski). The pieces sometimes meander, but following the workings of Sapolsky's limber mind is half the fun.

In the title essay, "The Trouble with Testosterone," for example, he admits to being "a member of a minority about which the stereotypes are indeed true. I am male." From there, though, he proceeds to dismantle popular notions of the role of testosterone in male primate aggression. Boys will be boys, Sapolsky writes, but not strictly because of testosterone. In fact, aggression actually triggers the release of extra testosterone, not the other way around. The point gets even subtler as Sapolsky explains that a certain baseline level of the male hormone must be present before aggressive acts will occur. But the environmental conditions that set the stage for fights and dominance displays--competition for food, sex partners or job promotions--must also be present. The hormone just pumps up the aggression volume.

This train of thought leads Sapolsky to touch on a theme that runs through these essays: the foolishness of the nature vs. nurture debate. He elegantly explains why "the hoary old dichotomy . . . is a sham." Animal behavior--from obsessive-compulsive disorder to sexual orientation--is not dictated solely by our genes or by our upbringing. "No biology. No environment," he writes. "Just the interaction between the two."

Even so, Sapolsky is fascinated by the nature side of the equation--the evolutionary baggage humans have inherited. He uses the lives and behavior of the baboons he studies each summer in Africa to shed light on the way their human cousins think and act. In "The Young and the Reckless," he describes the painful journey that every young male baboon makes when he "transfers" to another troupe. "There are no freshman orientation weeks, no cohorts of newcomers banding together and covering their nervousness with bravado," he writes. "There is just a baboon kid, all alone on the edge of a new group, and no one there could care less about him." Both humans and baboons leave home because, he concludes, the adventure is irresistible.

In most of The Trouble with Testosterone, Sapolsky presents himself as a buoyant pop culture addict as apt to quote Homer Simpson as Sigmund Freud. But in "The Dissolution of Ego Boundaries and the Fit of My Father's Shirt," Sapolsky switches to a different voice--subdued, almost elegiac--to recall his reaction to his father's death in 1994. The piece covers a lot of ground, from a meditation on the physical state of crippled physicist Stephen Hawking to a tour of the neuroscience behind multiple personality disorder, grief and depression.

But then Sapolsky turns his cold scientist's eye on himself. He notices that he is suddenly picking up his architect father's habits--drawing floor plans, humming old Yiddish tunes--and even wearing Dad's blue flannel shirts. For a few weeks, he loses his sense of self and at one point delivers the last few minutes of a lecture in his father's voice. At first he worries that he's suffering from a neurologic problem or mental illness, but in the end, Sapolsky finds a deeper understanding and reveals himself as a rationalist who revels in the mysteries of the irrational. He concludes that the brief lowering of his ego boundaries was a normal human reaction--one that science can't completely explain.

In the closing essay, Sapolsky reasserts his faith in the mysterious beauty of existence: "An impala sprinting across the savannah can be reduced to biomechanics, and Bach can be reduced to counterpoint, yet that does not decrease one iota our ability to shiver as we experience impalas leaping or Bach thundering."