What Don't We Know about Emotions?

The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.

— Ralph J. Boorstin

If you are like most people, you feel convinced that, because you have emotions, you know a lot about what emotions are, and how they work. We believe you are almost certainly wrong. In the field of emotion, as in most fields, familiarity is not the same as expertise. After all, you have a heart, but that doesn't make you an expert on hearts. You leave that to your cardiologist.

Yet the science of emotion is fraught with this problem: everyone seems to think they know what an emotion is. This is because we all have strong, and typically unjustified, intuitive beliefs about emotions. For instance, some people are absolutely certain that animals have emotions; others are absolutely certain that animals could not have emotions. Neither camp can usually give you convincing reasons for their beliefs, but they stick to them nonetheless.

We cannot emphasize enough the pervasive grip that our commonsense view of emotions has on how we (that is, researchers in the field) frame our scientific questions. We need to free ourselves of our commonsense assumptions — or at least question all of them — if we want to ask the right questions in the first place. This chapter introduces the topics of this book through this important premise and concludes by listing what we ideally would want from a mature science of emotion, and what entries in this list we will tackle in this book.

We wrote this book for two overarching aims. The first aim is to motivate the topic of emotion, to note that it is of great interest not only to laypeople but also to many scientific fields of study, and that it is a very important topic as well. At the same time, we emphasize that we currently know remarkably little about it yet — in particular, we know a lot less than we think we know. This is good news for scientists: there is work to be done, interesting and important work.

The second aim is to provide a summary of what we do know and to sketch a framework within which to understand those empirical findings and within which to formulate new questions for the future. This process is in practice very piecemeal: we need to have a little bit of data even to begin thinking about what emotions are, but then we discover problems with the way prior experiments were done and interpreted. In the dialectic of actual scientific investigation, both conceptual framework and empirical discovery are continuously revised, and inform each other. However, we have not written our book this way. Instead, we begin with some of the foundations for a science of emotion (chapter 2) — what kinds of ontological and epistemological commitments it requires, what kind of structure an explanation takes — and then work our way toward a list of features or properties of emotions (chapter 3), which then finally are the things we look for, and discover, through empirical research (chapters 4–9). We return to the foundations and the questions again in chapters 10 and 11 by contrasting our views with those of others, and by suggesting some experiments for the future.

Emotions According to Inside Out

What is it about emotions that we would like to understand? And what do we think we understand, but in fact don't (or are mistaken about)? Because emotions are ubiquitous in our lives, and integral to our experience of the world, it is dangerously easy to come up with simplistic views that do not stand up to closer scrutiny, and instead impede scientific progress because they create "the illusion of knowledge."

The film Inside Out, which won the 2016 Academy Award for Best Animated Feature, as well as a Golden Globe, provides a good example of many common but incorrect assumptions about emotion. As you watch the film, you get a fanciful view of how emotions are supposed to work inside a twelve-year-old girl, how those emotions are supposed to be integrated with memory and personality, and how they are supposed to be expressed as behavior. If Inside Out's view of emotion were right, you would be tempted to conclude that we understand an enormous amount about how emotions work — and, more generally, about how the mind and brain work. But Inside Out's view of how emotions work is wrong. In examining what, exactly, is wrong with it, we can highlight some of the gaps in our current understanding of emotion. If you've seen the film and you already find the view of emotion portrayed by Inside Out silly, you are ahead of the game — but bear with us as we use it as an example for uncovering problematic beliefs about emotion.

Inside Out's view of emotion takes as its starting premise the idea that all our emotions boil down to a few primary ones: in the film, they are joy, anger, fear, sadness, and disgust. These five emotions are animated as different characters, charming little homunculi that live in the brain of the little girl and fight with each other for control of her behavior and mental state. These homunculi sit at a control panel and watch the outside world on a screen. They react to the outside world, and in response they manipulate levers and switches that control the little girl's behavior. They are also affected by memories that are symbolized by transparent marbles; moreover, a series of theme parks provide a mental landscape symbolizing different aspects of the girl's personality. The five emotion characters fight over access to the memory marbles and struggle to keep the girl's theme-park attractions open for business.

From the film's point of view, the five emotions are the dominant force controlling the little girl's thoughts, memories, personality, and behavior; thinking, reasoning, and other cognitive activities are relegated to a sideshow. Truly, the little girl is an entirely emotional being. These details of the movie may not represent the way you think about emotions, but they characterize how many people do.

So what's wrong with the film's creative, engaging metaphor? Let's unpack a few of the key ideas about emotions that Inside Out showcases, highlight the errors in their underlying assumptions, and try to articulate the scientific questions that they raise. Although science may not yet have the answers, the...