[Column] How many emotions are there in me?

The movie "Inside Out" was released in 2015, and as a brain scientist, I consider it one of the best films of my life. Now, nine years later, a sequel has been released. While the sequel is just as captivating, it introduces new emotions and features many elements that resonate more with parents than with children. The movie has been particularly popular in Korea, where over 8.7 million people had watched Inside Out 2 as of Sept. 1.

After watching the movie, my kids asked, “Dad, do I have Joy, Sadness, and Anger inside my head, too?” I replied, “Of course! Those emotions exist in everyone!” That was my simple reply, but there’s a lot more to explain scientifically.

First of all, emotions aren't confined to your head. The brain interprets emotions by analyzing a range of factors, including heart rate, breathing, muscle tension, and more. Additionally, we don't experience just a few fixed emotions like joy, sadness, anger, and anxiety; instead, we feel a whole spectrum of emotions. It's important to note that neuroscientists and psychologists don't all agree on how emotions work, and there's ongoing debate in the field.

Are “Inside Out 1” and “Inside Out 2” based on real science? While we don't have a control panel inside our brains or emotions that run around as characters like in the movies, much of what we see is grounded in real research. Psychologists and neuroscientists were consulted to ensure accuracy. However, the portrayal of "emotions" in the films might align more closely with one perspective in the scientific community than with others, reflecting ongoing debates in the field.

From the 1970s to the 1990s, the most popular theory of emotions was the "five basic emotions" theory, which proposes that everyone experiences five core emotions. This theory was developed by Professor Paul Ekman, who identified joy, sadness, anger, fear, and disgust as the basic emotions. Professor Ekman served as the primary advisor for “Inside Out” 1.

However, according to Professor Lisa Feldman Barrett's new theory of emotion, which has emerged since the 2010s, we don't all experience just five intrinsic emotions. Instead, we have a much broader range of emotions. Barrett's theory suggests that emotions primarily arise when there's a mismatch between the brain's internal model of the world and actual experiences. Advances in computational neuroscience have led to theories of how emotions are modeled differently in various situations. This perspective is not reflected in the movie.

The scientific advisor for “Inside Out 2” was Dr. Dacher Keltner, a student of Professor Paul Ekman. Keltner has been actively researching a broader range of emotions. Initially, Keltner aimed to include 20 emotions rather than just five, but the writer and director decided it was challenging to depict so many emotions as characters, so the film features only several new ones. Professor Keltner, who also hosts the podcast “Science of Happiness,” studies various emotions including anxiety, envy, and embarrassment—emotions that were incorporated into “Inside Out 2.” The main plot of the sequel developed from conversations between Keltner and the film's primary writer, Pete Docter, about their own children entering their teenage years. The movie introduces four new characters—Envy, Embarrassment, Ennui, and Anxiety—to represent emotions commonly experienced by teenagers going through puberty.

The movie's message is both simple and powerful: to live happily, we must not let anxiety or envy take control of our minds. Instead, we should recognize that our sense of self is composed of a complex mix of emotions. Joy and sadness, anxiety and envy, anger and boredom—all these emotions are integral to who we are. “Inside Out 2” offers a poignant reminder that a healthy self can only grow when we embrace all our emotions and memories, both positive and negative.

We often don't talk about our feelings and memories enough, and it's important to create more opportunities to reflect on and analyze what memories shape us and why we are the way we are. In this context, watching these movies together as a family could be a great way to start those conversations. I want to have more opportunities to discuss with my family, especially my kids, about how I think about myself, how I feel, and what emotions I'm experiencing.

Chang Dong-seon is the CEO of Curious Brain Lab and resides in Seoul. He studied Biology at Uni Konstanz, Neuroscience at the International Max Planck Research School, and Cognitive Science at Rutgers University. Chang's career includes roles as an Assistant Professor at Hanyang University and a Researcher at the Max Planck Institute for Biological Cybernetics. He also served as the Head of the Future Technology Strategy Team at Hyundai Motor Group. His extensive expertise spans biology, neuroscience, and cognitive science. This column was originally published in Segye Ilbo in Korean on July 17, 2024. -- Ed.