Psychologists have shown that shouting people convey six different states and that they can easily distinguish positive exclamations from danger signals.
Screams often accompany feelings of fear and aggression. They warn others about the danger. This is how all great apes behave. But people sometimes scream for completely different reasons - for example, out of surprise. Psychologists at the University of Zurich have demonstrated that we use six different types of shouting and are even able to distinguish them by ear. They write about this in an article published in the journal PloS Biology.
Scientists recruited 12 healthy adult volunteers. They were asked to mentally immerse themselves in various positive or negative situations - for example, an attack on a dark street or the victory of their favorite team at the World Cup - and shout. The screams were recorded and then given to listen to several groups of other volunteers. In the first group, they had to assess how much the sound attracts attention, how strong it evokes an internal response (from 0 to 1); in the second group, they were asked to describe the nature of the cry (joyful, horror, and so on).
The authors conducted a series of such experiments with various variations, including in parallel tracking the brain activity of volunteers who heard the cry using a tomograph. This made it possible to distinguish six different forms of screaming, corresponding to different experiences: pain, anger, fear, pleasure, sadness and joy. Interestingly, it was not “negative” sounds (pain or anger) that elicited a stronger response, but “positive” sounds (joy and pleasure). The volunteers recognized them faster and more accurately on the recordings.
Why this happens is unclear, because, as far as is known, in other animals, screams serve only to warn of threats. However, the authors of the work suggest that the matter is in the highest sociality of a person. People spend almost all their time in the company of their own kind, and to maintain the stability of these ties, joint positive experiences are even more important than negative ones.