Study identifies six psycho-acoustically distinct types of screams, relaying emotions such as pain, anger, fear, joy, sadness, and pleasure. Non-alarming screams, such as expressions of joy and pleasure, are perceived and processed by the brain more effectively than screams of alarm.
When people hear screams of excited happiness, they tend to confuse the emotion with fear. Researchers say the bias toward categorizing excited and joyfully screams as fear has evolutionary roots.