How Emotions Are Made: The Secret Life of the Brain

Barrett argues that, like mental illness, physical illness can manifest itself in myriad ways depending on the individual, and that a constructionist approach may help illuminate why disease can present so differently in different people. While acknowledging that this chapter is “speculative,” Barrett emphasizes that it’s based on scientific data and helps show how chronic problems such as anxiety, depression, physical pain, and stress are connected.

Our daily activities prompt our brains to manage our body budgets by directing resources like oxygen and glucose to where they’re most needed. In a healthy person, the brain’s body budget can remain “solvent,” but if the brain often mispredicts the amount of fuel you need, it may prompt “survival circuits” that will greatly influence your budget. Unfortunately, if this misbalance becomes chronic, your body budget goes into “debt,” signaling your immune system to use cytokines to create inflammation. For example, if you live in a dangerous neighborhood and regularly hear threatening noise at night, your body may think you require more energy than you do, and it may release cortisol. The long-term consequence of too much cortisol in your bloodstream is an increase in inflammation, leaving you vulnerable to illness. This can trigger a “vicious cycle” of fatigue and low energy, weight gain, and chronic poor mood. Unfortunately, the proinflammatory cytokines responsible for this can also reach and influence the brain. Barrett calls the imbalanced body budget a “fertilizer for disease” (202), in which the immune system and inflammation are linked to illnesses like depression, heart disease, insomnia, and memory issues.

Barrett reports that this knowledge is prompting researchers to shift away from an “essentialist” view of disease that looks for specific fingerprints or symptoms to focus on the common components of illnesses, such as genetics or neural damage. The author argues that many mental illnesses we’ve traditionally considered distinct are products of the same root cause: an imbalanced body budget and long-term inflammation. Barrett thinks that—like our feelings—many diseases “do not have firm boundaries in nature” (203).

Barrett analyzes the role of stress in our health, making distinctions between brief instances of stress and the chronic stress of poverty or abuse. She laments that researchers have treated stress as different from emotion even though they’re constructed in the same way. An imbalanced body budget often provokes chronic stress, which is toxic for physical health and highly detrimental to brain function. Fortunately, Barrett provides evidence (in the last chapter) that these negative effects can be reversed.

Barrett then discusses pain, which can refer to a variety of experiences and results from a process called “nociception.” While scientists have long regarded pain as the result of an unpleasant interaction with the outer world, Barrett argues that predictive thinking also influences pain. Barrett cites studies that show that when people are given a placebo pill they think will ease their suffering, they report less pain. She ponders the role of interoception in creating pain sensations in the body and claims that the ability to tell pain, stress, and emotion apart is a kind of emotional granularity. Chronic pain, from headaches to back pain, afflicts millions of Americans and costs the US over $500 billion per year. Barrett blames incorrect brain predictions and inflammation for creating pain in people whose bodies show no physical damage. Like an amputee with phantom limb pain, these people’s brains continue to generate predictions that result in real pain after their injuries have healed: “Chronic pain seems to be a tragic case of predicting poorly and receiving misleading data from your body” (208).

The author then examines depression, another debilitating illness that affects millions of Americans, many of whom take antidepressants to seek relief. Barrett argues that, like other emotions, depression is a concept and the unfortunate result of your brain “continually mispredicting your metabolic needs” (210). As a result, depression sufferers feel fatigued and sad, while the body burns through excessive glucose, which raises the risk of diabetes, cancer, and other conditions. Barrett points out that negative feelings prompt negative thoughts, perceptions, and predictions. The vicious cycle of depression prompts your brain to try to “cut spending” by reducing movement and ignoring the external world; sadly, this only leads to more negative feelings. For these reasons, Barrett believes that depression isn’t solely a psychiatric illness but also a neurological, immunologic, and metabolic illness. Meaningful relief requires stopping the cycle of “misbudgeting” that fuels depression. Anxiety, on the other hand, is created by insufficient predictions from the brain, leaving the person feeling unsettled and uncertain, fueling anxious thoughts. Barrett believes that feelings such as anxiety and depression are “malleable” and that how people choose to label them can greatly influence how they experience them.

Barrett ponders the consequences of a brain struggling to make predictions and describes how many of its behaviors are similar to symptoms of autism. While she doesn’t claim to have proven a direct link, Barrett cites studies and firsthand accounts of autism that show that autistic people must try to learn to make conscious predictions that neurotypical people make automatically. Barrett concludes the chapter by emphasizing that to effectively influence one’s own moods and health, one must be able to separate physical reality from social reality while remembering the relationship between the two.

Barrett argues that any society’s “ultimate rules” that govern emotions can be found in its laws. Certain emotional states, such as a jealous rage, a frightened act of self-defense, or even romantic love, may be either excused or stigmatized depending on a state’s laws. Barrett observes that essentialism is “baked into the law” (220) and informs how we perceive crime and dole out punishment. The author recounts a so-called crime of passion in which a husband killed his wife’s lover by shooting him twice in the head. He argued that he wasn’t responsible for his actions because he was so upset and was convicted of second-degree murder rather than the more punitive first-degree murder. This kind of heat-of-passion defense is based on centuries-old beliefs about human emotions, especially that they make us more animalistic and that in certain situations our rational thoughts can fail to overpower them. The human brain is perceived as a “battleground” between reason and emotions. Barrett debunks these ideas by noting that anger has no biological fingerprint in the brain and that people can commit crimes out of anger that they’ve carefully planned for months. Additionally, some criminals can “think” themselves into committing a crime, even though no defense exists for violence due to a “fit of thinking” (223). Jealous or angry rages shouldn’t be considered as involuntary as reflexes, Barrett argues, because they’re the result of the brain’s predictive thinking rather than a simplistic stimuli-response relationship. She reiterates that emotions aren’t foreign forces that invade the body, or even mere reactions—they’re the brain’s constructions of the world.

She reflects on the common gender stereotypes in the US, including the widespread belief that women are more emotional than men and that men are more “stoic” and “analytical” than women. Studies confirm that some people feel emotions more intensely than others, but this can affect men and women equally. Unfortunately, these gender stereotypes can pervade legal settings and lead to harsher consequences for women. Barrett cites numerous cases in which women who hurt or killed their partners were given harsher sentences than men who committed the same crime. The sentencing tended to be even more punitive if the women were Black. The author argues that in the American imagination, women are naturally fearful and passive, but it’s considered unnatural for them to be angry, so judges and juries treat angry women more harshly.

Continuing her analysis of essentialist views and the legal system, Barrett casts doubt on legal arguments that try to equate specific brain regions or neurons with certain behaviors. Aside from brain tumors, which are sometimes responsible for major personality changes, blaming errant brain activity for someone’s behavior is incorrect. She then discusses the difficulty of determining whether criminals feel remorseful, since this depends on their cultural background and personal experience. As a jury member, being totally objective is impossible when evaluating whether someone feels remorseful, as one automatically generates predictions based on variable cues like facial expression, voice, and posture. However, determining remorse can be very consequential, especially in cases where the death sentence may apply.

The author considers the extent to which trials by juries can be fair given that mental inference about others’ emotions happens automatically and subconsciously. She claims that in the American legal system, judges and juries are meant to act as mind readers or lie detectors, which is an unrealistic assignment. Barrett notes that bias informs everyone’s perceptions, citing several studies to support her claim. Mispredictions and biases also guarantee that laws like “stand your ground” laws excuse the killing of innocent people, since such laws allow killers to use the legal defense that they perceived someone as being harmful. Barrett argues that, unfortunately, the human brain is wired for this type of “delusion,” which often results in unarmed, harmless people being mistakenly targeted. The law also tends to place great weight on eyewitness accounts, which Barrett says are often wrong, even when witnesses feel they’re telling the truth. As such, they’re really the least reliable form of evidence.

Barrett points out for judges to be purely rational in enforcing the law is physically impossible because “the brain’s wiring doesn’t divorce passion from reason” (238). She cites several studies with judges as subjects that showed that they could hand down different sentences depending on their physical state or the likeability of the people being charged. Given their immense responsibilities and the emotional nature of their job, judges have a great deal of “affect” that influences their work. The author argues that rather than deny the role of emotions in their work, judges should be aware of it and try to channel it appropriately. The author then ponders why emotional harm is considered so much more trivial than physical harm in the court of law, even when we know that emotional stress can have substantial consequences for people, including shortening one’s lifespan. Barrett points out that bullying in school is rarely brought up in courts despite its being proven to cause illness, brain development issues, and reduced IQ. Emotional distress and chronic pain are inconsistently awarded damages in court and are often less recognized than physical injury; Barrett thinks this is because they’re more difficult to objectively determine.

Building on her analysis of essentialist views and the legal system, Barrett argues that lawmakers and enforcers should understand five “teaching points.” The first is that emotions aren’t always readily visible in specific facial expressions. Second, whether one knows it or not, one’s perceptions are always “colored by [one’s] feelings” (244). Third, humans don’t have automatic emotion triggers that leave us completely at the mercy of our anger or other feelings. Fourth, blaming certain regions of the brain for crimes is “junk science.” Her fifth point is to be more aware of essentialist thinking that may reinforce certain prejudices—for example, that women shouldn’t express anger. Additionally, the “reasonable person standard” to which defendants are held is informed by stereotypes and needs to be reconsidered. She also ponders whether trials by jury should be discontinued given the difficulty in separating feelings, biases, and expectations from judgment.

Barrett then considers how, according to her constructionist view of the brain, everyone is responsible for their behavior, predictions, and concepts. By this thinking, criminals are to blame for their actions. Although the brains’ concepts are informed by the cultural environment, each of us is responsible for deciding which of these concepts to allow to influence our behavior. The author ends the chapter by reiterating her main points of argument and expressing hope that the legal system will soon look to the latest brain science to update its conventions and law enforcement.