BERKELEY, Calif. — Human emotions may not be as plentiful as the hundreds of emojis we use on social media, but they’re still more complex than previously believed. A new study examining the various ways that we express ourselves determined that humans display 27 distinct emotional states.
Researchers at the University of California, Berkeley recruited a diverse sample of 853 men and women to watch short five-to-ten second long video clips meant to evoke a range of reactions, hoping to measure the true spectrum of human emotions.
The study’s experimental component, which incorporated nearly 2,200 silent clips, split participants into one of three groups.
One group disclosed their unfiltered emotional reactions to 30 clips they viewed to the researchers, allowing for raw documentation.
“Their responses reflected a rich and nuanced array of emotional states, ranging from nostalgia to feeling ‘grossed out,’” says lead author Alan Cowen, a doctoral student in neuroscience, in a university news release.
A second group ranked each video in terms of the various emotional reactions it lent, ranging from anger to sexual desire. Most participants in this group gave each video similar marks when it came to the types of emotions it evoked.
A third group had participants evaluate the emotional content of a given video based on a sliding scale (e.g., how negative or positive a video was, or how exciting or boring it was).
Regardless of the group in which one was placed, nearly all participants reacted in a similar manner to any given video. Furthermore, the researchers were able to use this data to determine that humans have 27 distinct categories of emotion.
This finding is rather groundbreaking, considering how previous research had only identified six significant emotional states.
“There are smooth gradients of emotion between, say, awe and peacefulness, horror and sadness, and amusement and adoration,” notes senior author Dacher Keltner. “We found that 27 distinct dimensions, not six, were necessary to account for the way hundreds of people reliably reported feeling in response to each video.”
The research team hopes the new findings can be utilized by other scientists or doctors for further research and innovations in neuroscience.
“Our hope is that our findings will help other scientists and engineers more precisely capture the emotional states that underlie moods, brain activity and expressive signals, leading to improved psychiatric treatments, an understanding of the brain basis of emotion and technology responsive to our emotional needs,” says Cowen.
The team released an interactive map of the emotional states that each video used in the study elicited from participants that led them to their finding. Each of the 27 states corresponds to a color on the map.
The study’s findings were published this week in the journal Proceedings of the National Academy of Sciences.