PDF Summary:Incognito, by David Eagleman

In Incognito, David Eagleman explores a disconcerting concept—that the vast majority of your brain activity is unconscious and outside of your control. Comprising the bulk of your mental activity, your unconscious mind creates your perception of reality, allows you to perform complex actions without thinking about them, and makes snap judgments and decisions you’re unaware of. Because of this, Eagleman challenges the assumption that humans have free will—which, he argues, opens up important questions about criminal justice and prisoner rehabilitation.

Eagleman is a neuroscientist at Stanford University and the co-founder of two companies, Neosensory and Braincheck. He also directs the Center for Science and Law, a nonprofit that applies principles of neuroscience to improve the justice system. Our guide to Incognito unpacks Eagleman’s ideas about consciousness and free will, looks at the research behind these ideas, and explores other perspectives on criminal justice.

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These same unconscious processes allow you to form judgments about potential friends, romantic partners, purchases, and so on. They also underlie any “hunches” or “gut feeling”—both of which are simply terms for when your unconscious mind has come to a conclusion without your conscious mind knowing how.

(Shortform note: Research shows that trust plays a big role in your judgments about people and purchases, and your unconscious brain relies on both sensory input and abstract information to determine your level of trust. When making judgments about other people, you unconsciously consider factors like their body language, reputation, and whether they’re a member of your racial/ethnic group. When making purchases, you rely on heuristics like social proof (whether other people trust the product or brand). That said, how your brain interprets these cues depends partially on your culture; for example, body language that’s seen as trustworthy in one culture may not be perceived the same way in others.)

Your Unconscious Mind Controls Your Behavior

Eagleman also asserts that your behavior and decisions are ultimately controlled by unconscious processes. He explains that every aspect of your experience is the result of physical goings-on in your brain. While you experience yourself as making decisions with your conscious mind, Eagleman suggests this is an illusion—even conscious decisions are determined by neurological processes over which you have little control.

(Shortform note: This perspective is known as materialism. Materialists like Eagleman hold that there’s no mind separate from the physical brain—so all your experiences are the result of brain activity. In contrast, dualism holds that there is a non-physical mind that exists independently of the physical brain. Dualists argue that it’s hard to explain subjective experiences like color, taste, or emotion in purely materialistic terms, suggesting the existence of a non-material mind.)

To demonstrate how your decisions and behavior are determined by unconscious processes, Eagleman points out research indicating that your brain begins making a decision before you’re consciously aware of what you’ve chosen to do. Therefore, your conscious mind doesn’t actually “choose” what you do. He also highlights that people with Tourette’s syndrome experience themselves performing actions without their own consent, including facial expressions and outbursts of inappropriate language. This further undermines the belief that your behavior begins when you consciously choose to perform an action.

(Shortform note: As evidence for these conclusions about free will, some experts point to an experiment by neuroscientist Benjamin Libet which showed people making a decision before their conscious mind was aware. This experiment tested a participant’s decision to move a finger—a motor action that requires little conscious deliberation. However, some experts push back on this test as evidence against free will. They argue that the results of this experiment can’t be extrapolated to tell us about how we make larger conscious decisions, like where to live, who to marry, or what career to pursue.)

In addition to affecting individual decisions, Eagleman points out that a change to your physical brain can have a profound influence on your behavior. For example, some medications are known to decrease the user’s impulse control, leading to compulsive gambling, shopping, or drug use. People who suffer brain injuries have also shown dramatic behavioral changes, reinforcing the idea that it’s your unconscious brain that determines what you do, not your conscious self.

How Does Your Brain Make Decisions?

Why do brain injuries and certain medications have such a marked effect on your behavior? Neuroscientists say it has to do with the way your brain makes decisions. Decision-making is a collaborative process shared by multiple regions of the brain:

• Emotional parts of your brain, like the orbitofrontal and ventromedial areas, try to anticipate the outcomes of a decision, such as reward and regret.

• Analytical parts of your brain, like the dorsolateral prefrontal cortex, help you consider multiple pieces of information.

• The anterior and ventral cingulate cortex helps your mind to weigh different options and sort through potential outcomes.

• When acting on a decision, your brain shows significant activity in the corpus callosum, a part of the brain that facilitates communication and collaboration between the two hemispheres.

Since decision-making is such a complex process, a change to any region of the brain could hypothetically lead you to make and act on decisions differently than prior to the change. The complex nature of decision-making may also explain why people with neurological differences like Tourette’s syndrome exhibit uncontrollable behaviors. While the exact causes of Tourette’s are unknown, some have theorized that Tourette’s syndrome occurs because chemical neurotransmitters are not metabolized and processed correctly. This minor difference could possibly disrupt the brain’s complex decision-making circuitry.

Humans Lack Free Will

According to Eagleman, the fact that your behavior is controlled by your unconscious has startling and profound implications. Most of us assume we have free will—we’re autonomous agents who direct our own lives by making decisions based on reason or an inner voice. However, Eagleman argues that since your conscious mind can’t exist or function independently of your brain’s physical processes, you can’t have free will—there’s nothing “free” about decision-making processes directed by neurobiology. As we’ll see later in the guide, this has broad ramifications for the criminal justice system.

(Shortform note: Critics have pushed back on the idea that neuroscience debunks free will. Some have argued that free will’s existence doesn’t depend on it playing a role in every decision—if you consciously choose between multiple options at least some of the time, then you still have free will. Others have argued that the neurological processes that lead to a decision are still contained within a single person’s mind, and so the person, not their brain, has still made the decision. Some also assert that, given the enormous ramifications of the debate, neuroscientists should hold themselves to a higher standard of evidence before making sweeping declarations on free will.)

Your Conscious Mind Can Train Your Unconscious

While your unconscious mind is largely in control, there is one important way for your conscious mind to influence your behavior. Eagleman explains that your conscious mind can train your unconscious processes through intentional practice. Recall that the brain transfers frequently performed tasks to the unconscious so you don’t have to expend mental energy on them. According to Eagleman, this means that you can make conscious decisions about which activities to practice often enough that they become deeply engrained in your unconscious mind—so deeply engrained that you can then perform them automatically.

(Shortform note: This caveat seems to contradict Eagleman’s argument about free will because the idea that you can make some conscious decisions about which systems to train suggests that you have personal agency. Agency is defined as the capacity to act and is considered a core tenet of free will by those who argue that free will exists. However, as a materialist, Eagleman believes that all your mental processes are created by neurological activity—and, like other hardline materialists, he might argue that your sense of agency is only an illusion.)

As an example of a trained unconscious behavior, when someone is first learning how to type, they may have to look at the keyboard to remember where all of the keys are. They consciously decide to make a deliberate effort to practice typing. As they practice, their unconscious mind begins to remember where all the letters are, and eventually they can type entire words without looking at the keys or thinking about individual letters.

(Shortform note: Researchers have identified two factors that help you to encode skills and behaviors into your unconscious. The first one is variety: You can learn a skill better when you practice a range of different facets or techniques. For example, if you’re trying to improve at drawing, you could vary your practice by rotating between figure drawing, still life, and landscapes. Secondly, researchers have found that good sleep is essential for learning a skill. Your brain encodes memories while you sleep, so the more rest you get, the more your unconscious mind can build up the memory banks necessary for automatizing skills.)

Part 3: Reforming The Criminal Justice System

Eagleman argues that humans’ lack of free will has drastic implications for the criminal justice system. Historically, criminals have been sentenced on the assumption that they’re rational actors in control of their actions, and therefore need to be punished in proportion to their culpability. However, Eagleman says that since this assumption is false, the criminal justice system should treat criminals as if they’re incapable of choosing differently.

(Shortform note: Many societies throughout history have believed that humans have little or no control over the course of their lives. For example, the ancient Greeks believed that the length and events of a person’s life were determined by the three fates, or Morai, personified as three women making and cutting the cloth of a person’s life. However, this deterministic worldview existed alongside punitive justice systems: Criminals in ancient Greece could be exiled, sentenced to death, or even forced to wear burning clothes as punishment.)

Eagleman argues that instead of punishing criminals, incarceration should aim to reform them so they can be released back into society without reoffending. He says this approach is not only more humane, but it also has the potential to make society safer by preventing first-time offenders from committing additional crimes.

(Shortform note: Some research has found that a justice system focused on rehabilitation may also be more economical than a system focused on punishment. While rehabilitation reduces the risk that criminals will re-offend, punishment-based justice systems can increase the likelihood of recidivism. Those who reoffend after release must be reincarcerated at additional cost. One estimate published by the US Department of Justice found that every dollar spent on education or job training saved about 4-5 dollars that would have to be spent on reincarceration.)

Let’s take a look at how the ideal criminal justice system would work according to Eagleman.

How to Reform the Criminal Mind

Eagleman argues that because a criminal’s unconscious brain led them to commit their crimes, their reform should consist of retraining their unconscious. (Recall that the conscious mind has the ability to train the unconscious mind to make certain decisions and enact certain behaviors via conscious practice.)

Since poor impulse control is a trait widely shared by criminals, Eagleman argues that their criminal tendencies could be curtailed by strengthening their prefrontal cortex—the part of the brain most directly responsible for impulse control. His rehabilitation plan consists of exercises that increase connections and neural activity in this part of the brain, strengthening the criminal’s capacity to regulate their behavior.

He highlights one potential exercise: The incarcerated person is presented with an image of something that would normally tempt them, like an unattended purse. A scan of their brain measures the activity that accompanies their impulsive response. The prisoner is then responsible for figuring out a way to lower the activity associated with that temptation while their trainer continues the scan. According to Eagleman, repeating this exercise will strengthen the criminal’s unconscious ability to resist impulsive behaviors over time.

(Shortform note: Although Eagleman advocates using brain scans to help rehabilitate criminals, some experts raise ethical concerns about this approach. Some argue that neurological interventions may violate the privacy or mental autonomy of incarcerated people, and they question whether criminals should have the right to refuse treatment. Furthermore, some interventions may require supervision from physicians. These procedures would then have to follow the ethical codes of the medical profession, which include respecting the patient’s autonomy to make their own treatment decisions.)

Traumatic Brain Injuries: An Underlying Cause of Poor Impulse Control

Eagleman argues that strengthening criminals’ impulse control is key to reducing recidivism. But why do criminals tend to have poor impulse control in the first place? One answer is that incarcerated people are much more likely to have experienced traumatic brain injuries (TBIs) than the rest of the population. TBIs can negatively impact impulse control, increasing the likelihood of criminal aggression and substance abuse. Furthermore, once released from prison, those with TBIs are more likely to reoffend and be reincarcerated than those without. This suggests that TBIs likely play a substantial role in criminal behavior.

However, with current medical knowledge, the treatability of TBIs still depends on their severity, with serious TBIs taking years of rehabilitation. Some patients never return to their original level of functionality. That said, efforts are already underway to study the effects of TBI rehabilitation on rates of recidivism. If justice systems move toward reforming criminals as Eagleman advises, TBI rehabilitation may play a major role in reintegrating criminals into society.

Conditions For Release

Eagleman argues that once a criminal has been reformed, they should be quickly released. He explains that the justice system serves to protect the general population by isolating those who might cause harm to others—and once a criminal has been reformed, they no longer need to be contained. Therefore, only those who continue to pose a real danger should remain incarcerated for the long term.

How do we determine whether someone is reformed or is likely to reoffend? Eagleman argues that we should no longer rely on the intuitions and predictions of parole officers and specialists, as studies have shown these to be inaccurate. Instead, he recommends developing statistical models and gathering data to identify risk factors that will help to accurately calculate the probability of someone reoffending.

Furthermore, he argues that we should consider how well individual criminals respond to rehabilitation. Those who take well to treatments like the prefrontal cortex exercises should be released sooner as they’d be less likely to reoffend, while those who struggle to modify their behavior may need to be incarcerated for longer.

The Role of Prisoner Re-Entry in Recidivism

When attempting to predict which prisoners will reoffend once released, it’s important to note that some of the most important risk factors might not be known until after a prisoner is released. Some research suggests that recidivism has more to do with a prisoner’s ability to successfully re-integrate into society than with internal factors.

One study on prisoners released from federal US prisons in the 2000s found that 93% of offenders who secured employment for the entire duration of their supervised release were able to reintegrate into society without reoffending. On the other hand, 50% of offenders who weren’t able to find a job ended up reincarcerated for a new offense. This may happen because those who can’t secure legal employment turn to illicit means of supporting themselves.

However, getting a job out of prison can be extremely difficult, since up to 90% of US companies use background checks in their hiring process, putting convicted felons at a disadvantage. Furthermore, people who spend a long time in prison may have difficulties adjusting to life outside. They get accustomed to the highly structured nature of prison life and aren’t used to making a lot of everyday decisions or managing their own lives. Prison life can also take an enormous toll on someone’s physical health, adding an extra layer of difficulty to re-entry. The most effective way to reduce recidivism may be to combine rehabilitation techniques with programs to help prisoners re-enter society.