Laughter, bonding and biological evolution

This paper combines perspectives from evolutionary biology and linguistics to discuss the early evolution of laughter and the possible role of laughter-like vocalisation as a bonding mechanism in hominins and early human species. From the perspective of evolutionary biology, we here emphasise several things: the role of exaptation, the typically very slow pace of evolutionary change, and the danger of projecting backwards from the current utilities of laughter to infer its earlier function, hundreds of thousands, or even millions, of years ago. From the perspective of linguistics, we examine both the semantics of the word ‘laugh’ and the vocal mechanics of human laughter production, arguing that greater terminological care is needed in talking about the precursors of laughter in the ancient evolutionary past. Finally, we turn to hypotheses about how laughter-like vocalisations may have arisen, long before articulate language as we know it today. We focus in particular on Robin Dunbar’s hypothesis that laughter-like vocalisation, which stimulated endorphin production, might have functioned as a bonding mechanism (a kind of “vocal grooming”) among hominins and early human species. The paper contributes to the special issue theme (Humour and Belonging) by casting a long look backwards in time to laughter-like vocalisation as a distant evolutionary precursor of humour, and to bonding as an evolutionary precursor to cognitively and socially modern forms of “belonging”. At the same time, it cautions against casual theorising about the evolutionary origins of laughter.