6. The role of intersubjectivity in the development of intentional communication
The present account explains (i) which elements of nonverbal reference are intersubjective, (ii) what major effects intersubjectivity has on the general development of intentional communication and at what stages, and (iii) how intersubjectivity contributes to triggering the general capacity for nonverbal reference in the second year of life. First, intersubjectivity is analysed in terms of a sharing of experiences that is either mutual or individual, and either dyadic or triadic. Then it is shown that nonverbal reference presupposes intersubjectivity in communicative intent indicating and referential behaviour, and indirectly in modifications of previous behaviour in response to communication failure. It is argued that different forms of intersubjectivity entail different types of communicative skills. A comprehensive analysis of data on gaze-related intersubjective behaviour in young infants shows that interaffectivity and interattentionality enable referential skills early in development and together allow for complex behaviour. Early referential skills, it is proposed, arise by other mechanisms than in nonverbal reference. Reliable and consistent use of nonverbal reference occurs when interaffectivity and interattentionality coalesce with interintentionality, which affords general cognitive skills that together permit a decontextualisation of communicative behaviour.