Synchrony and joint attention development in infancy : a transactional approach

Joint attention is an early emerging skill that plays a critical role in early child development (Moore & Dunham, 1995). This shared engagement facilitates language acquisition (e.g., Morales et al., 1998) and predicts social cognition in early childhood (Van Hecke et al., 2007). Thus, it is important to understand factors contributing to individual differences in joint attention development. One potential predictor is mother-infant synchrony, the extent to which mothers’ verbal and nonverbal input is contingent upon their infants’ focus (Siller & Sigman, 2002). Researchers found synchrony to be positively associated with the rate of language development (Akhtar et al., 1991). However, few studies have examined mother-infant synchrony longitudinally and whether synchrony influences individual differences in joint attention. The present study is one of the first to examine these relationships in depth prospectively. Twenty typically-developing infants (11 male) and their mothers participated at approximately 9, 12, and 15 months of age as part of a larger longitudinal study of infants at risk for Autism Spectrum Disorders. Each dyad engaged in a 15-minute unstructured play session, which was coded for synchrony (Siller & Sigman, 2002). In addition, researchers administered the Early Social Communication Scales (ESCS; Mundy et al., 2003) with the infant, which was coded for Initiating Joint Attention (IJA) and Responding to Joint Attention (RJA). The results suggest that synchrony was stable within dyads across 9, 12, and 15 months. Surprisingly, higher 9-month synchrony was correlated with lower 12-month RJA. Growth curve modeling revealed significant growth in RJA, but not IJA, over time. However, synchrony scores did not significantly predict growth in IJA or RJA over time as predicted. These preliminary results suggest that synchrony is a relatively stable construct that likely reflects true differences between mother-infant dyads. Mothers following their child’s lead more often at 9 months had infants exhibiting less RJA at 12 months. Contrary to our predictions, there were no other significant associations between synchrony and joint attention. These findings will be reexamined upon collection of additional data. Nonetheless, the current study helps to elucidate the nature of synchrony and joint attention over time in infancy.