How Emotions Are Made: The Secret Life of the Brain

Using the lens of her constructed theory of emotion, Barrett questions whether animals have the three necessary ingredients to experience emotions: interoception, emotion concepts, and social reality. The author focuses on primate species since they’re most closely related to people. Like humans, all animals must manage their body budgets and therefore require an interoceptive network. In macaques, a kind of monkey, the interoceptive network is similar to that in the human brain. Macaques have also been shown to experience affect, as their nervous systems respond differently to positive and negative stimuli. Barrett argues that if macaques feel affect, then other primates would too, given their similarities. However, she’s unsure how other mammals function emotionally. She claims that they must “feel pleasure and pain, as well as alertness and fatigue” (255). Barrett notes that studying animal brains is challenging because some of their brain regions are similar to those in human brains but serve different purposes. The author argues that the most ethical approach is to assume that all animals can experience affect and some degree of emotionality. Humans have an unusually large “affective niche,” or the amount of things that can possibly influence your body budget and emotions. Even macaques don’t interact as much as people do and therefore don’t influence each other’s body budgets as much.

Experiencing emotion requires the ability to learn concepts. Barrett cites numerous studies that show that a variety of animals recognize different concepts naturally or through training, from letters and numbers to other animal faces. The author notes that scientists consider mental concepts solely the domain of humans, despite studies that attempted to train primates to engage with them. Barrett acknowledges that bonobos, a species of primate closely related to humans, seem to value socialization and communication more than other apes such as chimps and gorillas. While chimps have been the subjects of numerous studies, no one has found evidence that they can interpret a situation from different points of view, imagine an abstract future, or spontaneously use the words they know. And while chimps can certainly learn practices through observation, such as opening nuts with rocks or picking out termites with sticks, they don’t transmit social reality from generation to generation as humans do. As such, Barrett calls social reality a “human superpower.”

The author then shifts her focus to dogs, questioning whether they can form emotion concepts and social reality. Barrett argues that by selectively breeding dogs for so many thousands of years, humans have helped to create “a certain kind of dog nervous system” (264) that is more in tune with the human body budget. Dogs can be trained to identify visual and olfactory concepts, as many studies have shown, and may be able to infer human and dog intentions by focusing on gaze and body language. Barrett notes that she’s a “skeptic” about dogs being able to create emotion concepts but thinks it’s “remarkable just how much dogs and other animals can accomplish through affect alone” (267). Barrett recaps her passage by confirming that animals experience interoception, with which they regulate their body budgets. In addition, they have affect, can learn action concepts, and sometimes even acquire some words. However, they’re likely unable to make categories or create and teach specific concepts. They can, of course, recognize basic experiences like pain or pleasure, since they do have affect, and can also grieve the passing of canine or human companions, revealing a deep investment in their social community.

Barrett addresses the studies that claim to have identified emotions in various animals. She explains that by practicing “fear learning,” a process whereby animals associate an electric shock with a certain noise, scientists have learned that animals may experience a raised heart rate and other physical symptoms in response to the sound alone, revealing their ability to create a strong association. Barrett explains that “fear learning” is a kind of Pavlovian response that has its own “industry” of studies, including those on mental illness and drug development.

Barrett argues that these studies are hampered by the “mental inference fallacy” (272), which causes scientists to misinterpret a behavior (e.g., freezing in response to a sound) with a complex emotion (fear). The author explains that this kind of subconscious inference is how the human brain is wired. Barrett laments that by making a physical action, like freezing in place, synonymous with a mental state, psychologists have “sown confusion for decades” (273) about the nature of emotion and normalized this study approach. The author credits scientist Joseph E. LeDoux, a former proponent of fear learning, with realizing that the brain circuits in the rats that he was studying were in fact survival-driven circuits that managed freezing behavior and not the emotion fear. Barrett explains that mental inference toward animals isn’t all bad, as it can help generate empathy toward them, but it shouldn’t influence scientific work. Furthermore, she argues that we should focus on understanding animal brains “for their own sake, not as inferior human minds” (276). The author concludes the chapter by reiterating that while animals certainly have affect, emotion seems an entirely human phenomenon.