Behave: The Biology of Humans at Our Best and Worst

In this chapter, Sapolsky argues for an overhaul of the criminal justice system based on a deep integration of what we already know about the biological factors causing behavior but are unwilling to apply. Although Sapolsky clearly does not favor many of the topics he discusses from a scientific perspective, such as the science of genocide or conformity, this is Sapolsky’s most sustained and specific critique of an existing social system.

Sapolsky starts by listing several highly important topics in scientific reform to criminal justice. Sapolsky refers to these as “liberal reforms” (those focused on human rights, equality, and the correcting the systemic biases of the system). He compares these efforts to Johann Weyer’s 16th-century treatise for minor, scientifically informed reform to witch-hunt procedures, which were adopted but still left the industry of witch-hunting intact. This is “imposing some sound thinking in one tiny corner of an irrational edifice” (584). For Sapolsky, such partial reforms are insufficient. “Something more extreme is needed” (584). Another way to think of this critique is that each of these liberal reforms is about correcting an individual injustice within the justice system, such as unfair treatment of minorities. Sapolsky’s argument is that instead we need a complete epistemological overhaul of the very idea the system is based on, which is the idea of guilt’s connection to free will.

There are three ways we can view the relationship of biology and behavior in cases of adjudicating guilt: (1) we have complete free will in our behavior, (2) we have none, or (3) somewhere in between.

Western law exists in case three, where certain biological factors excuse us from the guilt we would put on others not exhibiting those factors. This is expressed in the concept of “mitigated free will,” i.e., “diminished responsibility for our actions” (587) due to factors such as psychosis, impaired cognitive development, even passion. These do not say we have no responsibility for our actions in these cases, just less. Furthermore, people who do not have such conditions are by default fully responsible for their actions. Sapolsky is highly critical of this view since it rests on the unscientific idea that some biological factors limit or overtake our free will but that free will does still exist, somewhere.

As this book has shown, the biological factors shaping behavior may be as minute and complex as the sternness of our parents in childhood or whether we have eaten today. Based on this finding, Sapolsky argues there is no free will; there are only systems of inter-related biological and cultural factors that determine our acts with an illusion of free will laid on top of them. As such, we can think of this chapter as the summative argument of the book: There is no free will. As backed by all the evidence presented beforehand, everything is actually biologically and culturally determined. This is Sapolsky’s strongest evocation of his own deterministic stance toward existence.

The concept of mitigated free will exists throughout the criminal justice system, where it works to draw lines between one interpretation of guilt and another. Eighteen-year-olds are taken as not emotionally and cognitively mature enough to be tried as adults in cases of murder. In other words, our legal system supposes a concept of stable free will, limited by the biological factor of incomplete development. But this supposes that those just under 18 are incomplete while those over are complete and capable—a biological fallacy. Another example is damage to the frontal cortex, which is a major predictor of violent crime. Our legal system says those with no frontal cortex function should not be treated as responsible. What about those with some frontal cortex function? What about those with poor frontal cortex communication to other brain regions? Our rules are inconsistent.

Another example of the mitigated free will fallacy is our idea that responsibility for acts increases as time to meditate on them increases. We are less responsible for our acts if they are reflexive or immediate—crimes of passion—than if they are reflected on for long periods—crimes of premeditation. Similarly, we are less responsible for acts driven by compulsions as survey of work on assigning guilt in cases of schizophrenic criminals shows (592-93).

Outside of criminal justice, another line drawn in mitigated free will is between aptitude and effort. We view aptitude—athletic and intellectual ability—as innate and biological while we view hard work as a decision based on free will. The issue of course is that our capacity for grit is itself a biological phenomenon influenced by things as mundane as hunger and sleep quality and as severe as brain trauma or parental abuse. Our capacity to work hard is just as much biological as our innate aptitudes.

There are critiques that our current state of half-integration of neuroscience into the justice system is already an excessive intrusion. These critiques commonly argue that neuroscientific research is descriptive in nature, not causative. Correlating behavior X to activation of brain region Y is not a causal explanation of why an act occurs; it is a redescription of the act’s occurrence. This is true of brain imaging studies in a vacuum. However, “transcranial magnetic stimulation techniques that transiently activate or inactivate a part of the cortex can change someone’s moral decision making, decisions about punishment, or levels of generosity and empathy. That’s causality” (600). In other words, damage to or manipulation of certain brain regions predicts higher rates of certain behaviors. The problem is that this is not true in each individual case.

Neurobiology of behavior is multifactorial, which is why a broken leg predicts inability to walk immediately afterward 100% of the time, but a missing prefrontal cortex predicts violent behavior less than 50% of the time. We cannot explain behavior through brain genetics, chemistry, life history, cultural setting or immediate stimuli individually. However, our predictive power ramps up significantly when we look at all of these factors in synthesis, which is the definition of multifactorial analysis.

People believe in free will because it is more intuitively easy than understanding and interpreting all these factors synthetically. On top of this, neuroscience is quite young, but even in this time it has revolutionized our understanding of several phenomena we used to assign will (and therefore guilt) to: epilepsy, dyslexia, mental disorders, for example. Committing to the idea that science will come to explain more phenomena we cannot explain today also means committing to the ever-diminishing role of free will in our discourse. In the future, we will look back on today’s systems of punishment and see them as just as antiquated as witch trials and bloodletting.

This does not mean we should do nothing about criminals. People must be protected from others who are dangerous. Furthermore, even punishment of criminals has a place in a behaviorist framework since punishing undesirable behavior assists in conditioning toward desirable behavior. The problem, however, is that punishment as a tool for cooperation is central to the evolution of society, so it becomes attached to concepts of morality. Punishing others also triggers dopaminergic activity. It feels good to punish, and we think we are doing something good for society, so we do it far too much. We must distance ourselves from the idea of the virtue and righteousness in punishment or that certain crimes deserve punishment as an appropriate response. After all this, however, Sapolsky offers very little in the way of a new criminal justice system to be implemented.

In this chapter, Sapolsky unabashedly declares himself a determinist: someone who believes all events within a system are determinable based on conditions of the system at the outset of the event. This is the importance of multifactoriality, in the confluence of all the biological components, from large to small, from the observable to the fleeting, we do get to a complete causal picture of behavior. Free will is nowhere to be found.