UC Santa Barbara

Earlier intervention for infants and toddlers with autism spectrum disorder (ASD) enhances developmental gains (Rogers, et al. 2012) and necessitates ascertainment of early, reliable indicators of ASD. Diminished social attention and positive social affect have been among the leading hypothesized risk factors for ASD in the prelinguistic period, between 6-12 months of age, however research has resulted in mixed findings for the predictive value of social engagement in 6-9-month-old infants for the development of ASD. If abnormalities in infant social affect contribute to the early phenotypic expression of ASD, it is important to determine whether diminished social affect is a unique construct associated exclusively with social impairments or if it is, alternatively, an expression of normal variation in individual development better explained by temperamental style. The current study sought to enhance the understanding of social development in early infancy by investigating individual differences in social engagement during face-to-face dyadic interactions. Expression of positive social affect during a structured dyadic parent-infant interaction was measured for 33 typically developing 6-8-month old infants. This measure was then correlated with concurrent clinical measures of social-communication, vocal production, autism symptomology, and temperament. Results revealed a positive association between positive social affect and the receptive language component of social-communication. No significant relations were observed between positive social affect, vocal production, autism symptomology, or temperament. These results suggest that infant positive social during interaction with a caregiver is a reflection of some elements of social-communicative ability for 6-8 month old infants, but not temperamental style. Further research is needed to understand how diminished positive social affect in early infancy may impact later developmental outcomes. Implications for early identification of ASD and relevant intervention strategies are discussed.