When you hear a scream, you automatically perk up. It catches your attention. But scientists are still working to define what exactly makes a scream. People scream when they are scared or happy. It’s not just a humans, either—all types of animals scream, from frogs to macaques.

Psychologist Harold Gouzoules and his team measured the acoustic properties of a human scream by actually playing screams for people: Screams of fright, screams of excitement, and even a whistle. He joins Ira to talks about the evolutionary basis of screaming and what it can tell us about how human nonverbal communication.

Further Reading

• Read the original research paper in the Quarterly Journal of Experimental Psychology.
• Learn more about why screams make you shudder in this interview on Science Friday.
• Read about scream therapy on Inverse.