The evolution of silence: The role of inter-turn speech pauses in the co-evolution of language and cooperation

Abstract

Language and cooperation are tightly linked aspects of human interaction, with language serving as a tool to assess potential cooperation partners. We propose that inter-turn speech pauses, which have essential social-communicative functions, have played a significant role in the co-evolution of language and cooperation. Our experiment investigated how listeners use the duration of these pauses to assess knowledge, confidence, and willingness in conversation partners. We found that long pauses are generally perceived as indicative of lower competence and willingness. However, listeners were more tolerant of long pauses in non-native speakers, interpreting them as the result of prolonged cognitive processing in a non-native language. This pattern was consistent across languages and cultures. Our follow-up study explores whether these relationships persist when participants don't understand the language, supporting the idea that pauses may have been used as early communicative signals before fully-developed shared linguistic systems existed. Additionally, inter-turn pauses may be promising for investigating links between communication and cooperativeness across species.