Many animals—including sea lions, red deer, and dogs—use vocalizations to judge one another’s size and physical formidability when in competition for mates or other resources. Now, researchers reporting in the journal iScience on June 28 have found that humans can use nonverbal vocal cues, including aggressive roars, in a similar way. The new evidence is the first to show that, from a vocalization alone, human listeners can estimate whether another person is stronger or weaker or taller or shorter than they are with a high degree of accuracy.