Actions speak louder than words in socially foraging human groups.

SOCIAL FORAGING IN HUMANS HAS A DEEP EVOLUTIONARY HISTORY: early hominids searched for dispersed food sources in a patchy, uncertain environment. A fundamental assumption is that social foragers benefit by exchanging information about food sources, in order to make collective decisions based on pooled information. We conducted the first experimental test of this assumption, and showed that, as predicted, communication significantly enhanced group performance. A further, unexpected result was that physical communication through gesturing, rather than verbal communication, appeared to play a crucial role in the early stages of group interaction, facilitating consensus decision making by groups.  The importance of gestures in human interactions may therefore be underestimated, and this has important implications for modern human societies, where communications are becoming increasingly dominated by virtual modes of communication that preclude the use of gestures.