Testing joint attention, imitation, and play as infancy precursors to language and theory of mind

Various theoretical accounts propose that an important developmental relati on existsbetween joint attention, play, and imitation abilities, and later theory of mind ability. However, very little direct empirical evidence supp orts these claims for putative "precursor" theory of mind status. A small s ample (N=13) of infants, for whom measures of play, joint attention, and im itation had been collected at 20 months of age, was followed-up longitudina lly at 44 months and a battery of theory of mind measures was conducted. La nguage and IQ were measured at both timepoints. Imitation ability at 20 mon ths was longitudinally associated with expressive, but not receptive, langu age ability at 44 months. In contrast, only the joint attention behaviours of gaze switches between an adult and an active toy and looking to an adult during an ambiguous goal detection task at 20 months were longitudinally a ssociated with theory of mind ability at 44 months. It is argued that joint attention, play, and imitation, and language and theory of mind, might for m part of st shared social-communicative representational system in infancy that becomes increasingly specialised and differentiated as development pr ogresses. (C) 2001 Elsevier Science Inc. All rights reserved.