Human beings are better at responding to screams of pleasure or joy than screams of alarm, a new study has found.

Published in PLOS Biology yesterday, the study explains that human screams exist on a spectrum and can represent one of six emotions: pleasure, sadness, joy, pain, fear, and anger. This means humans are among the only known species to use their vocal ability to communicate feelings of joviality as well as alarm.

The findings also contradict the concept of ‘threat bias’, which suggests that we have evolved to pay exaggerated, selective attention to threats in particular — making it a key survival tactic. Turns out, we might be more responsive to joyful shrieks.

“The results of our study are surprising … Researchers usually assume the primate and human cognitive system to be specifically tuned to detect signals of danger and threat in the environment as a mechanism of survival,” Sascha Frühholz, an associate professor of psychology at the University of Oslo in Norway, and the lead author of the study, told CNN.

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While conducting the study, the researchers played loud sounds similar to screams in front of participants, mirroring feelings triggered by a range of scenarios: “being attacked by an armed stranger in a dark alley,” “try[ing] to intimidate an opponent,” having “your favorite team win the World Cup,” or simply, “sexual delight.” Employing functional magnetic resonance imaging, or fMRI, which measures brain activity, the researchers found that human brains react faster to positive, non-alarming screams — than those raising alarm. Not only that, they were able to identify screams of pleasure and joy more accurately.

The researchers think the findings are indicative of the way non-vocalized speech — screams and other sounds we make — have evolved. “Only humans seem to scream in ‘non-alarming’ contexts, but this phenomenon [of non-vocalization speech] has so far been completely neglected in scientific research,” Frühholz told Inverse. Scream communication, he adds, seems to have largely diversified in humans, and this is a huge evolutionary step in itself.

While there might not be an explanation for these findings just yet, Frühholz does have a hypothesis to make sense of this.

He posited that while the human brain, much like that of other species, works as a “threat detector,” there’s more to it due to the complexities of the social environments human beings exist in. Expressing, and in return, understanding positive emotions may be as relevant to the “dynamics of [our] social interactions,” making us scream for reasons other than raising alarm too.

While more research is needed to prove his theory, the present study can, perhaps, pave the path for future research.