[PS-1.18] Six-month-old infants are sensible to turn-taking violation

Durier, V. , Rabiller, A. , Dollion, N. , Lemasson, A. & Barbu, S.

UMR 6552 Ethologie Animale et Humaine, CNRS-Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France

Turn-taking is an important characteristic of conversational skills, where speakers and listeners alternate smoothly their roles, avoiding overlaps and extensive gaps between turns. A child needs more than 3 years to handle turn-taking skills although alternated vocalisations with his/her parents become predominant around the age of 9 months. Our experiment aimed to assess the ability of 6-month-old infants to perceive a breach of turn-taking characteristics: namely overlap. The infants watched videos of three sketches in which two women spoke to them. Three different situations were presented to each infant: 1) the first speaker turned towards the second person to allow her to speak; 2) the second speaker started speaking right as soon as the first speaker has finished; 3) the second speaker started to speak before the first speaker has finished (=overlap). The pictures of both speakers were presented side by side before and after each sketch. We measured the looking time at each speaker before and after each sketch. The infants looked longer at the second speaker after she overlapped the first one in the conversation. Overlap perception by infants seems to occur around 6 months, even before they are able to alternate smoothly their vocalisations with their parents.