Behave
By Robert Sapolsky, Penguin Press, 800 pages, $15
You reach out to touch someone’s arm, or perhaps you pull a trigger. What made that happen? In this extraordinary survey of the science of human behaviour, the biologist Robert Sapolsky takes the reader on an epic journey backwards through time, and through different scientific disciplines. His governing question is: what explains the fact that humans can massacre one another but also perform spectacular acts of altruistic kindness? Is one side of our nature destined to win out over the other?
The backwards time-travel is an excellent organising principle. Seconds before our action, it is neuroscience that investigates what is going on in the brain; minutes to days before is the domain of endocrinology (hormonal fluctuations). Days to months before, we focus on the brain’s ability to learn and rewire itself. Sapolsky goes back through adolescence, childhood and gestation (including genetics), and, beyond the birth of the individual, to more distant causes still _ those found in culture, evolutionary psychology, game theory and comparative zoology. He makes the book consistently entertaining, with an infectious excitement at the puzzles he explains, and wry dude-ish asides. (Humans, he notes, can “delay gratification for insanely long times” compared with other animals.
“No warthog restricts calories to look good in a bathing suit next summer.”) He likes to call certain facts “boggling” when he is personally amazed by them; it’s charmingly infectious.
This book is a miraculous synthesis of scholarly domains, and at the same time laudably careful in its determination to point out at every step the limits of our knowledge. Sapolsky offers a vivid account of a standard view before lining up complications or objections to it from other research, particularly in brain science. (Testosterone, for example, does not cause aggression but amplifies pre-existing tendencies for or against it. The actions of such molecules in general “depend dramatically on context”). In a phrase that has unfortunately become associated with the dishonest attempts to smuggle creationism into American schools, he is adept at “teaching the controversy”, often providing anecdotes of scientists with battling views from decades ago. Throughout, he insists on how much individual variability there is hidden beneath the statistical averages of studies, and how the explanation of nearly every human phenomenon is going to be “multifactorial”: dependent on many causes. The literature on one scientific question, he notes comfortingly, is “majorly messy”.
Along the way there are many counterintuitive ideas and stern lessons. Empathy — feeling someone’s pain — is not as likely to lead to useful action as dispassionate sympathy, or “cold-blooded kindness”. Income inequality is concretely causally bad for the health of the poorer. There is a well-established link between rightwing authoritarianism and lower IQ. Genes are not destiny, and they are not “selfish” a la Dawkins; “we haven’t evolved to be ‘selfish’ or ‘altruistic’ or anything else — we’ve evolved to be particular ways in particular settings”.
(According to one astonishing survey, 46 per cent of women would save their own dog rather than a foreign tourist if both were menaced by a runaway bus. The evolutionary explanation is that they feel more “kinship” with the dog.) In general, if our worst behaviours are “the product of our biology”, so are our best ones. That Sapolsky’s heart is evidently in the right place makes it easy to discount certain hippyish outbursts such as that the invention of agriculture “was one of the all-time human blunders”, since it led to sedentary living and social hierarchy. Sure, but it also led to wine, science and books, which I’d suggest on balance makes it rather a good thing.
More thorny is the point at which he comes to address the question of individual choice and responsibility. For nearly 600 pages, barring the odd mention of the “cognitive” aspects of human action, Sapolsky sidelines the question of what place conscious reasoning has in determining behaviour, among all the neurochemical, hormonal, developmental and evolutionary factors he has been discussing. Indeed, sometimes he writes as though it has no place at all, as when he asks what sensory input “triggered the nervous system to produce that behaviour”. He eventually nails his colours to the mast of strict determinism: every human action is inescapably caused by preceding events in the world, including events in the brain. So there can be no such thing as free will. (It follows, of course, that social systems such as that of criminal justice must be completely overhauled, as philosophers such as Ted Honderich have long suggested.) You think you can freely choose to do one thing or another? Forget it, Sapolsky says.
It’s a common view, though by no means the overwhelming philosophical consensus. Notably, he prefers to cite mainly neuroscientists and legal scholars. Sapolsky ends the chapter with a display of his pleasingly undogmatic spirit, confessing that he finds it impossible actually to live his life as though he does not have free will. It’s perhaps worth noting, too, that one study he does not mention here (by Kathleen Vohs and Jonathan Schooler in 2008) implies that the idea we have free will, whether true or not, is a crucial placebo idea for a well-functioning society: in the experiment, subjects convinced they didn’t have free will were more likely to act unethically.
But Sapolsky’s insistence on the truth of strict determinism poses wider problems for the way he frames the rest of his book. One thing he refreshingly emphasises is that reason and emotion (“cognition and affect”) always interact, and that there are advantages to “combining reason with intuition”. This is a welcome counterbalance to the recent misanthropic strain of psychology that seeks to downgrade rationality altogether, but it is not clear that, on Sapolsky’s own view, conscious reasoning can accomplish anything at all if decisions are inexorably determined by the laws of nature. Which poses a challenge to his own humanistic optimism. We are not at the mercy of our amygdala’s fearful response to human faces of a different race, he argues; we can dampen and overcome such prejudice through reflection. Yet on his own view, we cannot freely decide to do so.
For the same reasons, it is unclear how much value there is in the author’s uplifting exhortations to think more carefully about our actions, and even to imbue politics with a new kind of science-based “peaceology”. Perhaps the idea is that such encouragement will be a new part of the causal chain affecting each individual’s behaviour, so compelling his readers to act more sociably. In which case I hope this book sells several billion copies.
It remains debatable, though, whether strict determinism is compatible with Sapolsky’s final message of hope for humanity, as he tells inspiring stories about moral heroism in history — the helicopter officer who stopped the My Lai massacre, the Christmas Day football match during the First World War. Sapolsky is on the side of Steven Pinker’s argument, in The Better Angels of Our Nature, that humanity is overall getting less violent and nasty, and points to some lessons from the “social plasticity” demonstrated in troops of baboons, one of Sapolsky’s own specialities. He thus sets himself against conservative pessimism about brutish human nature. “Anyone who says that our worst behaviours are inevitable knows too little about primates, including us.”
Yet the question remains: if human beings are simply reactive robots, slaves to natural law who are causally buffeted by a zillion factors of biology and circumstance, why would we have any say in whether things get better? Either they will or they won’t, but on this magisterial account it seems that we can’t really choose to do anything about it.
–Guardian News & Media Ltd
