What controls our lives? Our own choice or fate? We figure out what answer modern science gives to this with Robert Sapolsky’s new book “It’s Decided: Life Without Free Will”
Renowned neurobiologist and Stanford University professor Robert Sapolsky is one of the most authoritative authors and popularizers of science. For over 30 years, the scientist worked on research into the behavior of baboons in Kenya, where he studied the mechanisms of stress in primates. Based on this material, Sapolsky wrote several books that became world bestsellers, in particular, “The Biology of Good and Evil,” which received the Enlightenment Prize in 2020. In his new book, Robert Sapolsky develops his ideas in a radical way; he considers free will to be an illusion, and our decisions to be predetermined by biological factors and the environment.
As any reader who has been, is, or will be a teenager no doubt knows, it is a very difficult stage of life. Emotional turbulence, reckless risk-taking and thrill-seeking, peak time for extremes of both pro- and antisocial behavior, the desire to stand out while at the same time fitting in; behaviorally, adolescence is a monstrosity in itself.
Neuroscience, too. Much of the research on adolescence is about why teenagers act like teenagers; our goal is to understand how the adolescent brain helps explain the intent to push buttons in adulthood. Conveniently, the same fascinating area of neuroscience applies to both. By the time adolescence begins, the brain is pretty close to its mature version, with adult neuron and synapse density; the process of myelination is already complete. There is one area of the brain that, surprisingly, will take another decade to mature. What is that area? The frontal cortex, of course. It “matures” much more slowly than the rest of the cortex—a phenomenon that is common in all mammals, but especially noticeable in primates.
Some reasons for this delay are easy to explain. Myelination of the brain, for example, begins in fetal life and gradually increases until it reaches adult levels; the frontal cortex is no exception, it’s just that the process is significantly delayed. But when it comes to neurons and synapses, the picture is completely different. When a child is just entering adolescence, his frontal cortex has more synapses than an adult. In adolescence and early adulthood, the frontal cortex prunes synapses that are unnecessary, unimportant, or simply incorrect, and the cortex itself gradually becomes more compact and toned.
As a clear example, a 13-year-old and a 20-year-old can perform equally well on a test assessing the functioning of the frontal cortex, but the former will have to use more of it to pass the test successfully.
So the frontal cortex—responsible for executive function, long-term planning, delay of gratification, impulse control, and emotion regulation—is not fully functional in teenagers. What do you think that explains? Pretty much everything that happens in adolescence, especially if you add to the explanation the tsunami of estrogen, progesterone, and testosterone that floods the brain. The relentless force of drives and urges, all held in check by the flimsy brakes of an immature frontal cortex.
We don’t care about the delay in maturation of the frontal cortex because it causes teenagers to get silly tattoos; we care that adolescence and early adulthood are the years of a massive construction project in the most interesting part of the brain. The implications are clear. If you’re an adult, your adolescent experiences of trauma, excitement, love, failure, rejection, happiness, despair, acne—all of these played a disproportionately large role in shaping the frontal cortex that now helps you think about those two buttons. There’s no doubt that the vastly varied experiences of adolescence shape the vastly varied frontal cortexes of adults.
One particularly fascinating consequence of this slow maturation is important to remember when we get to the section on genes. By definition, if the frontal cortex is the last part of the brain to mature, then it is the part of the brain that is shaped minimally by genes and maximally by the environment. This raises the question of why the frontal cortex matures so slowly. Is the blueprint itself more complex than the rest of the cortex? Does it require specialized neurons, neurotransmitters that are difficult to synthesize, unique synapses so bizarre that they require extensive assembly instructions? No, there is almost nothing unique about the frontal cortex.
Thus, if we take into account only the complexity of the frontal lobes, it cannot be said that delayed maturation is inevitable, and that the frontal cortex would mature faster if only it could.
No, this delay has actively evolved, has undergone selection. It is this area of the brain that primarily decides how to act correctly when it is most difficult to do so, but no genes can determine what is considered the right thing to do. This must be learned long and hard, from personal experience. The same is true for any primate forced to navigate the intricacies of social relations: who to be rude to, who to bow to, who to be friends with, who to stab in the back.
If this is important to baboons, what can we say about humans? We are forced to internalize the rationalizations and hypocrisies of our culture – thou shalt not kill, unless it is one of THEM, in which case here is a medal for you. Don’t lie, unless the lie promises a huge profit, or unless it is for a genuinely good cause: “No, sir, there are no refugees hiding in my attic, of course!” Laws to be obeyed without fail, laws to ignore, laws to resist. Live as if each day were your last, and at the same time as if it were the first day of the rest of your life. And so on and so forth. Just think: other primates finish developing their frontal cortex at puberty, but it takes us another decade. There is something remarkable here – the genetic programming of the human brain has evolved to free the frontal cortex as much as possible from the influence of genes. We’ll learn more about the frontal cortex in the next chapter.
So, adolescence is the final phase of formation of the frontal cortex of the brain, and this process is strongly influenced by the environment and experience. Moving further back into childhood, we find there a large-scale construction of all areas of the brain, a process of gradual increase in the complexity of neural networks and myelination.
Naturally, behavior also becomes more complex. Logical thinking, cognitive abilities, and emotions develop, which are necessary for making moral decisions (enabling, for example, the transition from obeying laws in order to avoid punishment to obeying laws because what would happen to society if people did not obey them?). Empathy develops (the ability to sympathize with emotional pain, not just physical pain, abstract pain, pain you have never experienced yourself, the suffering of people who are not at all like you). Impulse control strengthens (which at first helps you not to eat a marshmallow but to wait a few minutes for someone to give you two marshmallows, and which later helps you focus on your 80-year project of choosing a nursing home to your liking).
In other words, the hard stuff comes after the easy stuff. Child development researchers typically divide these maturational trajectories into “stages” (for example, the canonical stages of moral development identified by Harvard psychologist Lorenz Kohlberg). As you might expect, there is enormous variation in exactly where children of the same age may be in their maturational process, how quickly they move from one stage to the next, and which stage carries over into adulthood.
Back on topic, you now have to ask where individual differences in maturation come from, how much of it is controllable, and how it helps you become the button-gazing you. What factors influence maturation? Here’s a list of the most common suspects, with brief descriptions:
Parenting style , of course . Differences in parenting have been the focus of a very important paper by UC Berkeley psychologist Diana Baumrind. There is the authoritative parenting style, which places high demands and expectations on the child but is flexible in responding to the child’s needs; this style usually inspires neurotic, middle-class parents. Then there is the authoritarian parenting style (high demands, low responsiveness: “Because I said so!”), the permissive style (low demands, high responsiveness), and the indifferent style (low demands, low responsiveness). And each of these produces different types of adults. As we will see in the next chapter, the socioeconomic status of the parents also matters greatly; for example, low socioeconomic status predicts delays in the maturation of the frontal cortex already in preschoolers.
Peer group socialization , where different members of the same age set different behavioral examples with varying degrees of attractiveness. Developmental psychologists often underestimate the importance of peers, but primatologists know it well. Humans have invented a new way of transmitting knowledge between generations, where an adult professional, such as a teacher, specifically teaches young people. In contrast, primates typically learn by watching their elders.
Environmental influences : Is the park safe in your neighborhood? Are there more bookstores or liquor stores in the area? Is it easy to find healthy food? What is the crime rate? Nothing unexpected.
Cultural beliefs and values that influence all of the above. As we will see, culture has a significant impact on parenting style, the behavior modeled by peers, and the kinds of communities that form within it. Cultural diversity in hidden and overt rites of passage, the kinds of religious communities, and the kinds of behavior that children are encouraged to do, such as earning badges for academic achievement or bullying outcasts, all play important roles.
