A human scream would instill more fear when faced with the threat of imminent danger, or involvement in social conflicts. Such screaming can also show a person's joy or excitement.
For the very first time, researchers have shown that our brains perceive and process non-alarming screams more effectively than alarming ones, according to a report from ANI.
Humans Scream to Show Diverse Emotions
Because screaming can save lives, non-human primates and mammals most often use scream-like calls when caught in intense conflicts or alert companions of incoming predators and other threats. Though humans likewise scream to signify that they are in danger or show their aggression, they also scream in delight, anger, and despair. However, previous studies only focused on screams that signal alarming fear.
ALSO READ: Three Benefits of Anger
Humans Respond More Quickly to Positive Screams
In this study, "Neurocognitive processing efficiency for discriminating human non-alarm rather than alarm scream calls," of which findings were published in the PLOS Biology journal, researchers found out that humans respond more quickly to positive screams with higher sensitivity.
The team probed what the wide spectrum of human screams meant. The findings showed six emotionally unique types of scream calls that would indicate anger pain, pleasure, fear, joy, and sadness.
"We were surprised by the fact that listeners responded more quickly and accurately, and with higher neural sensitivity, to non-alarming and positive scream calls than to alarming screams, lead author Sascha Fruhholz of the University of Zurich Department of Psychology said in the study.
Researchers did four experiments, with 12 participants being asked to make alarming and non-alarming screams in response to various situations. A separate group rated the emotional nature of the screams and categorized them into specific classifications. As the participants heard the screams, their brain activity was monitored using magnetic resonance imaging (MRI) , tracking how they perceived, recognized, processed, and classified the screams.
More Neural Activity and Connectivity with Non-Alarming Screams
The scientists discovered that the frontal, auditory, and limbic brain regions exhibited more activity and neural connectivity upon hearing non-alarming screams than processing alarming scream calls.
In the past, human and primate cognitive systems were assumed to specifically designed for identifying threat and danger signals through screams. Compared to primates and other animal species, human scream calls apparently have been more diversified through the course of human evolution.
Diverse Nature of Scream Calls Show Immense Evolutionary Achievement
The authors said these findings reveal that scream calls are more disparate in their signaling and communicative nature in humans than frequently believed.
And this, the researchers believe, is an immense evolutionary achievement.
"It's highly possible that only humans scream to signal positive emotions like great joy or pleasure. And unlike with alarm calls, positive screams have become increasingly important over time," Fruhholz further said.
Researchers said that humans' complex social environments led to communicative demands that elicited a diversified set of scream calls.
RELATED ARTICLE: Why Do Some Men Respond Aggressively To Threats To Manhood While Others Are Not
Check out more news and information on Psychology on Science Times