The human scream signals more than fear of imminent danger or entanglement in social conflicts. Screaming can also express joy or excitement. For the first time, researchers have demonstrated that non-alarming screams are even perceived and processed by the brain more efficiently than their alarming counterparts.
Screaming can save lives. Non-human primates and other mammalian species frequently use scream-like calls when embroiled in social conflicts or to signal the presence of predators and other threats.
While humans also scream to signal danger or communicate aggression, they scream when experiencing strong emotions such as despair or joy as well. However, past studies on this topic have largely focused on alarming fear screams.
It was previously assumed that human and primate cognitive systems were specially tailored for recognizing threat and danger signals in the form of screams.
In contrast to primates and other animal species, however, human scream calls seem to have become more diversified over the course of human evolution.