The evolution and social functions of human nonverbal vocalisations

Dr. Katarzyna PISANSKI

Human nonverbal vocalisations such as screams, cries, and laughter convey socially vital information, yet have received far less attention than speech. We still know very little about how emotional vocalisations develop, how we use them in everyday life, or how they vary across cultures.  While human vocalisations share important features with the calls of other mammals including primates, humans are unique in one crucial respect: we can flexibly and deliberately modulate our voices for social ends, for instance by exaggerating or completely faking pain or pleasure. In this talk, I argue that our advanced capacity for volitional vocal control represents a critical bridge between animal calls and human speech. I will present evidence that (1) the acoustic forms of human vocalisations have evolved to support their communicative functions; (2) voluntary vocalisations systematically exploit these same form–function mappings for social benefit; (3) data from children and deaf adults show that such vocal control depends on learning; and (4) cross-cultural findings reveal both universal patterns and culturally specific variation in emotional vocalisations. Together, this body of work shows that human vocalisations — and our capacity to produce them voluntarily — are powerful social tools shaped by both selection pressures and social experience, offering unique insights into the evolution of vocal control.