Why do people shout for joy? New study looks at the psychology of human screams

Story Transcript

One of the most intense ways people share their emotions is through screaming. Whether it's at the sight of a cockroach, or the arrival of an ice cream truck, or even as a soccer player scores a winning goal, that loud cry can express a great fear or joy.

And while psychology studies have long recognized the alarming screams, not much has been known about their positive counterparts — until now.

A new study out of Switzerland identified six different types of screams that are typical of human beings —  pain, anger, fear, sadness, joy and passion. The findings were published last week in the journal PLOS Biology.

Lead author Sascha Frühholz, a University of Zurich psychologist, says the study revealed that people perceive and process positive screams "more efficiently" than the alarming ones.

"[The participants] were much more able to classify or to distinguish these positive screams — so, joyful screams or pleasure screams — and had much more problems justifying or detecting what we call the negative screams — so, like, fear screams or anger screams," Frühholz told As It Happens host Carol Off. 

One person starts to scream. The other person hears the scream and then feels probably the same kind of joy and screams along with the other people. And we think these positive screams have really a function of creating social bonds between people.- Sasha Früholz, lead author

That's "really surprising," he said, because previous studies look at the human scream with an evolutionary hypothesis.

"People usually say screams have evolved during evolution because of the powerful signal of telling another person there's something dangerous in the environment. There's a threat and we have to leave because this could cause some harm," he said. 

But things are different now, he said. 

"The common threats of danger that animals experience in their natural environments, they don't really much more occur in human environments," he said. "We think of it like the positive emotions are much more relevant for humans because they are much more able to regulate social interactions."

In the first part of the study, the researchers invited people to their lab where they set up individual sound-proofed rooms for recording. 

There were 12 participants with an even gender split. The researchers gave them specific scenarios to imagine that could trigger a rush of emotions, then asked each of them to scream into their microphones.

"We told them [you] can produce any type of scream, intense as you can, actually. And this is what they did," Frühholz said. "Then they produced the screams, and they did a really good job."

In the second part of the study, another group of participants listened to the recordings of the screams to try to determine the emotions behind them.

The researchers studied these participants' brain activity when they listened to the scream recordings using fMRI technology. In terms of how they perceived, recognized, processed and categorized the sounds, the researchers saw a difference between the positive and negative screams.

 "The frontal, auditory and limbic brain regions showed much more activity and neural connectivity when hearing non-alarm screams than when processing alarm scream calls," Frühholz said a press release from the university.

So why do people really scream?

According to the study, a person screams when they're in a certain emotional state. Something in the environment has to trigger that response, which Frühholz calls the "expression component."

At the same time, when someone screams, they are letting another person know how they're feeling. That "communication component" shows how screams can be a blunt way of sharing that information.

This is another reason why the researchers believe positive screams are a way of socializing.

"We go to concerts of famous bands. We go to football games. These are typical environments where we don't go alone. We go with friends. And usually we scream," Frühholz said.

"One person starts to scream. The other person hears the scream and then feels probably the same kind of joy and screams along with the other people. And we think these positive screams have really a function of creating social bonds between people."

Written by Mehek Mazhar. Interview with Sascha Frühholz produced by Rachel Adams.