Determined: A Science of Life without Free Will

Sapolsky compares examining a discrete behavior as an act of free will to interpreting a full-length movie having only watched the last three minutes. Sapolsky then introduces the concept of intent, arguing that intent is irrelevant to free will because it ignores most factors contributing to a certain behavior. In a thought experiment, Sapolsky says that if someone were hooked up for an electroencephalogram (EEG) and told not to think of President Harrison but to plan to think of him later, and then push a button when the thought occurred, the EEG would show brain activity before the button was pushed.

Neuroscientist Benjamin Libet constructed this model of experimentation in 1983; he asked subjects to push a button and to record when they decided to push it. Libet found that readiness potential—brain activity correlated with the decision to move—occurs before a person decides to push a button. These findings have been replicated and expanded by multiple scientists and studies, demonstrating that the sense of agency is an illusion.

Libetian experiments have been met with significant criticism: They have been deemed irrelevant and artificial, semantically misleading, and correlative rather than causal. Others question the role of consciousness in the process, and some counter that humans exhibit “free won’t” rather than free will. These criticisms have all been rebutted through tailored Libetian experiments that continue to demonstrate the same results.

Sapolsky concludes that Libetianism is irrelevant, only showing that “certain measures of brain function are moderately predictive of a subsequent behavior” (36). He argues that all the debates around Libetianism come down to a question of intent. For example, he questions whether a shooter should receive a lesser sentence if they miss their intended target. In the justice system, intent is a complex concept and is analyzed through multiple perspectives, such as specific or general intent or whether the intent emerged acutely as a result of intense emotions or was premeditated.

Despite the legal assumption that a person can intend to commit a crime, Sapolsky continues to refute free will through another thought experiment: A researcher devises a Libetian experiment that, instead of pushing a button, involves pulling a trigger to kill a person. The subject has the option to shoot, to not shoot, to shoot and miss, or to shoot the researcher. Despite the outcome, Libetian findings are irrelevant because they focus only on a moment before the decision, yet the reason for the decision must be examined in a broader context. Sapolsky suggests that morally judging the behaviors of others shows a lack of empathy. He points to philosopher Daniel Dennett, who claims that an individual’s advantages and disadvantages average out with time, implying that life is essentially fair. Sapolsky directly contests this idea, declaring that luck generally compounds over time. For this reason, it is unethical to judge a behavior merely based on present intent.

Sapolsky addresses the origins of intent, examining the seconds, minutes, days, years, and centuries before an intent is formed. First, Sapolsky looks at the seconds to minutes before an intent is formed. At this stage, one’s intent is impacted by their sensory perceptions, even those that are subconsciously registered. Multiple studies have revealed the effect of sensory information on decision-making. For example, the inability of the insula—a region of the brain that processes disgust—to differentiate moral and physical disgust has been shown to lead to less tolerance of gay marriage. Other studies have shown that the brain cannot distinguish between beauty and goodness or between moral and physical cleanliness, and hunger has been proven to influence judges’ sentencing decisions.

The next time bracket explores the minutes and days before a formed intent, with a focus on the effect of hormones. Higher testosterone, for instance, can make a person feel threatened or arrogant more easily and can increase impulsivity. In addition, hormones are affected by various factors, including a person’s state of health, genetics, and the time of day. Finally Sapolsky shifts to the weeks and years before a behavior, examining neuroplasticity, or the ability for the brain to change by forming new neural connections or eliminating existing ones. He argues that some examples of neuroplasticity suggest a deterministic universe. For instance, the brains of individuals with post-traumatic stress disorder respond to trauma by increasing the size and sensitivity of the amygdala, the brain’s center for anxiety, aggression, and fear. Similarly, the hippocampus, tied to memory and learning, will shrink with long-term depression and has been shown to grow in those who exercise regularly. Gut bacteria, too, has been linked to neurological changes.

During adolescence, individuals experience significant neurobiological shifts that affect their brains. The frontal cortex has yet to fully develop—an evolved trait that enables humans, as well as other primates, to learn social rules—meaning teenagers have more difficulties with planning, executive functioning, and impulse control. Sapolsky connects this to the free will discussion by arguing that adolescent experiences will have a major effect on the formation of a person’s frontal cortex and, thus, will affect how intent forms. Childhood plays a similar role as adolescence; however, while most of the brain is fully formed in adolescents, most brain structures are still forming in childhood. Childhood brain development is influenced by a number of factors, including socialization, parenting, and the communal and cultural environments. These factors can cause epigenetic changes, or changes that influence the expression of genes, sometimes across multiple generations. The Adverse Childhood Experience score measures negative childhood experiences, and a higher score predicts antisocial and impulsive behaviors and mental health issues. That good and bad luck compound is further exemplified through the findings that children’s age relative to their classmates affects their academic performance, with older children increasingly achieving higher academic scores.

Moving on to the fetal development stage, Sapolsky demonstrates that fetuses are affected by their mother’s diet, hormonal environment, oxygen levels, and other contributing factors, with implications for adult behavior. Moving to genetics, Sapolsky writes that 95% of DNA consists of “switches” that control gene expression, demonstrating how environment influences epigenetic expression. Behavior is inevitably affected by a person’s genetics and epigenetic expression.

The last segment covers the centuries before an intent, and it demonstrates that culture significantly influences both neurobiology and behavior. Cultural effects on intent and behavior are discussed through the differences between people from various cultures—individualistic versus collective, “loose” versus “tight,” and pastoral versus agricultural or hunter-gatherer. Sapolsky briefly mentions evolution as a factor before concluding that the areas of influence are “seamless” and leave no room for free will to affect intent or behavior. That the effects of luck intensify rather than even out over time is shown through Neil Levy’s work, further supporting that there is a lack of room for free will in our understanding of intent and behavior.

Sapolsky refutes the notion that free will occurs elsewhere—in social interactions, the past, or the future. He proposes a situation in which a man with a troubled past is attacked, shoots his assailant, and waits 11 seconds before firing a second shot to kill the attacker. Subsequently, he is charged with premeditated murder because he took 11 seconds to shoot. Compatibilists (those who believe free will and determinism are compatible) might agree with the charge based on the concept of “free was,” or that he was free to choose to be a different person in the past, which Sapolsky negates by revisiting the evidence that luck compounds over time. Robert Kane argues that free will occurs during difficult choices, while Sean Spence posits the opposite—free will happens during optimal moments. Peter Tse suggests that a person has free will to choose who they will be in the future. Adina Roskies and Michael Gazzaniga theorize that free will exists in brain areas and social interactions, respectively. Sapolsky refutes these ideas by referring to his prior position that there is no room for free will.

Sapolsky transitions to how the illusion of free will emerges, sharing an anecdote of two baboons, Kato and Finn, hunting together. Finn tackles Kato, who is more dominant. Kato stops supporting Finn, who then falls into the hierarchy of the troop. The same dynamic is seen among humans. Sapolsky invokes the word “squander,” which people often assign to individuals who don’t seem to live up to their potential. Although a person cannot control their attributes, free will supporters posit that a person can choose what they do with their attributes. This is exemplified through pedophilia; studies show that genetic and experiential factors contribute to pedophilia, but it is argued that while pedophilia is not a choice, molestation is. Accepting that humans are biological organisms is difficult, and many cite willpower as the seat of free will.

Choosing the right action instead of the easy action happens in the prefrontal cortex (PFC); for instance, the PFC is activated in reversal tasks, where a subject is given one set of rules to follow that is later reversed. The PFC’s main role is assisting in social behaviors, and increased sociality is correlated with a larger PFC. The PFC regulates emotional responses driven by the amygdala, as seen in people suppressing their implicit biases. Once a behavior becomes routine, the PFC no longer activates; however, if the PFC is damaged, a person will exhibit disinhibition. Sapolsky posits that the divide between emotional and rational thinking is a false dichotomy. The dorsolateral PFC (dlPFC) is a rational subset of the PFC, and the ventromedial PFC (vmPFC) relays information from the emotional, or limbic, system. Both the logical and emotional portions of the PFC are needed to optimize moral decision-making: “dlPFC damage produces inappropriate, emotionally disinhibited behaviors. But without a vmPFC, you desiccate into heartless detachment” (103).

Sapolsky uses the time bracket structure to examine the PFC with the hypothetical scenario of pushing a button on the left for a blue light and one on the right for red and then having those rules repeatedly switched. In the preceding seconds to minutes, the PFC is affected by a person’s cognitive load, or the amount of energy the PFC has been expending. The circulating hormones in the hours to days before affect PFC function, as do the structural changes that have taken place in the years to decades before. The PFC is still being formed during adolescence, childhood, and fetal development, so it is significantly affected by environmental conditions. Genes and evolution contribute to the type of PFC a person has, and culture, as previously mentioned during the discussion on intent, is passed on to each person and affects their behavior. Sapolsky concludes by declaring that “grit,” occurring in the PFC, is just as uncontrollable as natural attributes, supported by his demonstration that the factors that influence the PFC are “seamless.”