Center for Healthy Minds

What have researchers learned about the roots of human emotion? That’s the focus of “The Nature of Emotion, 2nd Edition,” a recently published book drawing from scientific experts including collaborators and scientists from the Center for Healthy Minds offering multiple viewpoints on the nature and origins of emotion. 

Center collaborator and co-editor of the book Alexander Shackman shares the latest research on the mind and our understanding of our emotions. Shackman is an assistant professor in the department of psychology and the director of the Affective and Translational Neuroscience Laboratory at the University of Maryland. The co-editors of this book are Richard Davidson, Andrew Fox and Regina Lapate.

What’s unique about this book?

We’ve built upon the legacy of previous editions and selected more than 100 leading emotion researchers from around the world and asked them to address fundamental questions about the nature and origins of emotion, looking at what’s generally agreed upon as a field and where the jury’s still out.

What shifts have occurred in the study of emotion?

Affective scientists agree that emotions evolved, that they are more adaptive than not and that they are central features of daily life. But beyond this limited agreement, recent years have witnessed a vigorous and persistent debate about the nature of emotion with leading theorists challenging shared conceptual assumptions that has inspired and guided the field for the past quarter-century. 

At the heart of this debate lies a fundamental question: What are emotions and how should we define them? Are they natural objects waiting to be discovered and catalogued (like stars) or are they constructs imposed by humans on the natural world (like constellations)? How one chooses to answer this question has clear ramifications for every other fundamental questions about the nature of emotion.

What have we learned about the science of emotion in recent years?

We’ve learned that emotion plays a central role in human experience and there is an abiding interest, among scientists, clinicians and the public at large, in understanding the nature of emotion, identifying its biological underpinnings, and determining its contribution to other psychological processes, from cognition and decision-making, to health and disease. 

Over the past quarter-century, methods for eliciting, assessing and analyzing emotion have become increasingly refined and techniques for making sense of the underlying neurobiology have become more powerful and precise. The roughly 100 essays that make up the new edition of The Nature of Emotion embody many of these exciting developments and make plain the important conceptual advances that have been made since the publication of the first edition in 1994. Despite this progress, it is clear that our understanding remains far from complete.

One of the most striking developments has been the growing prominence of neuroscientific approaches to emotion or what has become popularly known as affective neuroscience. Skeptics have questioned whether neuroscience can provide conceptually important evidence, and hundreds of millions of research dollars have been spent on the assumption that it can. There is compelling evidence that studying the brain is useful for determining the nature, and not just the biological bases, of emotion. 

We also know that neurobiology has been helpful for unveiling otherwise hidden features of emotion. For example, we’ve learned that reward (or pleasure) is not a single, indivisible thing, but can instead be split into wanting (appetitive motivation, craving and desire) and liking (hedonic pleasure and positive emotion). A similar story has emerged for fear, with mounting evidence that fear can be broken into two or even three more basic constituents. Beyond their implications for emotion theory (e.g., How many emotions are there? Are emotions organized into families?), these data provide new insights into both how we can better understand the underpinnings of addiction and anxiety disorders.   

What are the challenges facing this field of research and what are the most fruitful avenues in the future?

Although the field has made considerable progress since the publication of the first edition of The Nature of Emotion in 1994, it is clear that our understanding remains far from complete. Some challenges are conceptual. For example, we still do not know much about the cascade of psychological and neural processes that link specific emotional challenges to the appropriate responses. We do not yet have a deep understanding of how the brain chooses a particular suite of responses in the face of conflicting information. Given an approaching danger and a possible means of escape, how does the brain “choose” between evading detection, flight or active kinds of defense?

Other challenges are more methodological in nature. For example, the biomedical sciences are currently wrestling with problems of not being able to replicate research findings. Studies that we thought were rock solid – ones that have been incorporated into textbooks or used to guide the development of new treatments for disease ­­– have upon re-examination failed to replicate. This problem is not specific to affective science or even psychology, it's a much broader problem.

In the book, we discuss a number of approaches, many of them quite simple to adopt, that can enhance the reproducibility of emotion research. Another methodological challenge stems from the gap separating work in humans and animal models, mice, rats and so on. Both are important, but too often they are siloed by the customs and conventions of contemporary research, presented at different research conferences, and reported in different journals, read by different communities of scientists. 

We also emphasize the need to go beyond the lab. Are insights gleaned in the lab or in the scanner really relevant to everyday life, to real-world experiences and phenomena? It's an important question, with important implications for health, well-being and disease – after all, disorders of emotion do not arise in the lab, they evolve and unfold out there in daily life.

Some of the most important substantive areas for future research in the emotion sciences includes work focused on understanding the interplay between emotion and cognition, the myriad ways in which we (intentionally or unintentionally) regulate one another’s emotions, the role of microbes in our guts and bodies, and the mechanisms that underlie the development and malleability of emotion across the lifespan.

- Interview conducted and edited by Jon Hess