麻豆传媒

FOR sheer ambition, it鈥檚 hard to beat Robert Sapolsky鈥檚 new book, Behave. Sapolky鈥檚 goal is nothing less than a new way of seeing ourselves, free from separate 鈥渂uckets of explanation鈥� and walled-off sub-disciplines.

Biology alone isn鈥檛 enough, he explains, to understand the roots of cooperation, empathy and altruism (our best side), and violence, aggression and competition (our worst). Sapolsky, a professor of biology and neurology at Stanford University, California, brings in psychology and culture too, for all are 鈥渦tterly intertwined鈥� in our behaviour. And everywhere the writing is informed by his vast, world-leading knowledge of baboon behaviour.

Unsurprisingly, the book comes to a huge 790 pages, requiring time, stamina and a liking for Sapolsky鈥檚 chatty and exuberant style. It reflects its author, a 鈥渃ard-carrying liberal鈥� with a great grey beard and a quirky personality, who tells us that violence 鈥渟cares the crap out of me鈥�.

Sapolsky鈥檚 avoids the buckets of explanation through a device akin to the film-maker鈥檚 zooming out. His opening chapter looks inside your brain during the second before you do something, be it good or bad. Here you learn to be fluent in a new way of thinking, seeing behaviour as something modulated by interactions between amygdala, hippocampus, insula and, most important, the subregions of the frontal cortex, which try to plan and control.

Sapolsky adds more regions, the nucleus accumbens and the tegmentum, as he explains the relentless logic of the brain鈥檚 inner dopamine-based reward system. It ensures that what was 鈥渁n unexpected pleasure yesterday is what we feel entitled to today, and what won鈥檛 be enough tomorrow鈥�.

We zoom out to ever-wider horizons: past the outer and inner sensations that affect you in the minutes before a decision, past the hormonal states that operate over hours to days, and on to the extraordinary plasticity of the brain, which allows change over days to months.

Pull back again, through childhood and adolescence, the influence of the genes you inherit, the centuries of culture which affect how you categorise the world, and out to our primate relatives, where we witness the evolutionary pressures shaping our ways of thinking and feeling. By then you are at the midpoint of the book, where Sapolsky encourages you with a 鈥渘o one said this was easy鈥�, although by now the hard work is done.

鈥淚f 鈥榳e鈥� screw up, it is down to special circumstances. If 鈥榯hey鈥� do, it鈥檚 because that鈥檚 how 鈥榯hey鈥� are鈥�

Having mastered his lessons, you will find, as you chat with friends, a new sensibility to the inner question, 鈥淲hy did I just say that?鈥� This sensibility reaches through the tiny biases and physiological states that made one sentence pop out rather than another, through the inner tremblings of fear and anxiety, right back to an understanding of the primate roots of our obsession with rank and hierarchy. It takes in the status differences we detect in a blink of an eye, our ever-shifting groupings of 鈥渦s鈥� and 鈥渢hem鈥�, and why some two-thirds of our daily speech is gossip (鈥渨ith the vast majority of it being negative鈥�, Sapolsky reminds us).

You can then breeze through the book鈥檚 second half, in which you zoom in and out of levels of explanation, examining big questions about the best and worst of our behaviour. Hierarchy, obedience, morality, the hidden perils of empathy, free will, evil and criminality, war and peace are all here.

Sapolsky explores at length our inescapable and terrible tendency to create us/them dichotomies. The process is not only quite automatic but also easy to manipulate, altering our sense of who belongs to 鈥渦s鈥� and 鈥渢hem鈥�. We readily forgive 鈥渦s鈥�; if 鈥渨e鈥� screw up, it is because of special circumstances. If 鈥渢hey鈥� do, it is because that is how 鈥渢hey鈥漚re.

Sapolsky鈥檚 liberal bent is everywhere apparent. He is passionate about the terrible things that childhood deprivation and inequality can do to people鈥檚 brains and health. He is also disturbed that people living in unequal societies become less kind and more likely to displace their anger on to those lower down in the pecking order: 鈥淕iving ulcers can help you avoid getting them,鈥� he writes.

Sapolsky so dislikes the 鈥渃austic, scarring impact on minds and bodies鈥� inflicted by the socio-economic status quo, which arrived with agriculture, that he values older, egalitarian hunger-gatherer groups. 鈥淎griculture. I won鈥檛 pull any punches 鈥� I think that its invention was one of the all-time human blunders, up there with, say, the New Coke debacle,鈥� he writes, not entirely joking.

He is passionate too about reforming the justice system: words like forgiveness, evil, soul, volition and blame 鈥渁re incompatible with science and should be discarded鈥�, he argues. It angers him that it took so long for post-traumatic stress disorder to be recognised as a 鈥渞eal鈥� condition for US military personnel, and scorns lawyers who use bogus ideas from genetics, like the 鈥渨arrior gene鈥�, to excuse their clients鈥� wayward behaviour.

By the book鈥檚 close, Sapolsky attempts a summary of what he has said. It turns out to be: 鈥淚t鈥檚 complicated.鈥� This is a brave message in the age of Trump, but enigmatic too. I think Sapolsky means that 鈥渃ontext鈥�, a word he uses often, is always critical.

You may view testosterone, for example, as the male hormone that boosts aggression. Wrong, says Sapolsky. Rising testosterone levels do prompt behaviours aimed at maintaining social status. But if that requires people to be nice, extra testosterone makes them more generous. 鈥淚n our world riddled with male violence, the problem isn鈥檛 that testosterone can increase levels of aggression. The problem is the frequency with which we reward aggression,鈥� he writes.

Context wins, again

Oxytocin you might see as the 鈥渓ove hormone鈥�. Wrong again. Oxytocin does elicit 鈥渢rust, generosity, and cooperation鈥�, but only among 鈥渦s鈥�. Bring in some of 鈥渢hem鈥�, and oxytocin amplifies pre-emptive aggression and 鈥渁dvocacy of sacrificing Them (but not Us) for the greater good鈥�.

And you might think that 鈥渁 gene causes some biological event to happen鈥�. Not at all. Sapolsky urges you to repeat the mantra: 鈥淒on鈥檛 ask what a gene does, ask what it does in a particular context.鈥� Take the 5-HTT gene, which affects the removal of the neurotransmitter serotonin from synapses. One variant increases the risk of depression, but only in the context of childhood trauma.

Moving on to culture, context wins again. Zoom in, for example, on the common view that boys 鈥渘aturally鈥� reach the top levels of mathematics. It might seem true in US schools, but the more gender-equal the country, the better girls are at maths. In Iceland, 鈥渢he most gender equal country on earth鈥�, girls are better at maths than boys.

From my reading of this book, Sapolsky sees life as 鈥渃omplicated鈥� because there are always contexts, possibly ones we are unaware of, in which things could go some other way. Even he seems a little overwhelmed by it all. 鈥淣othing seems to cause anything; instead everything just modulates something else,鈥� he muses. This seems far from an 鈥渆ssentialist鈥� view of life as linear causation, and closer to seeing it as a network of possibilities, with an open future.

鈥淚f maintaining status requires people to be nice, extra testosterone makes them more generous鈥�

Whether the thought of life as 鈥渃omplicated鈥� appeals to or appals you may reflect something profound about human nature. Sapolsky explores research on how liberals and conservatives think. Liberals are more comfortable with 鈥渋ntegrative complexity鈥�, whereas conservatives dislike ambiguity or novelty, and crave structure and hierarchy. If you are a liberal, you may be happy that this sprawling book has no one simple conclusion; if you are more conservative, its apparent incoherence may prove worrying.

Inevitably, Sapolsky does not try to say what constitutes 鈥済ood鈥� or 鈥渂ad鈥�, although we do learn how these categories may differ across cultures and be shaped by ecological circumstances. But he does shift the perspective from which we might view our behaviour, and offers pithy insights to help us do it. Two I liked: 鈥淲e are constantly being shaped by seemingly irrelevant stimuli, subliminal information, and internal forces we don鈥檛 know a thing about鈥�, and 鈥淭he road to hell is paved with rationalization鈥�.

And, most important, never let your frontal cortex get tired: it consumes huge amounts of energy and when stress and cognitive load tire it out, you start to screw up.

This article appeared in print under the headline 鈥淚t鈥檚 complicated鈥�