The overarching goal of the proposed project is to rigorously test an intervention program for parents and their infants at-risk of an ASD that is developmentally informed, child-centered and focused on joint attention, a core deficit in young children with autism and an important area of concern for at-risk infants. An early intervention research classroom focused on core deficits of Joint Attention, Symbolic Play, Engagement and Regulation (Baby JASPER) will be compared to a hospital based early intervention program that focuses on early motor development, cognition, adaptive and social skills (Baby Standard). Parents will be provided with training in both classrooms and children will receive therapist led intervention sessions and a weekly home visit to practice generalization of skills. This project tests whether a classroom focusing on joint attention and object interest/play facilitates greater social-communication outcomes than a widely used early intervention curriculum focused on broad developmental goals. The project addresses gaps in the 2011 lACC Strategic Plan, including the identification of individual characteristics that predict response to interventions, clinical trials aimed at identifying active ingredients of effective treatments, and identification of biological signatures as related to treatment response. This project has the potential to identify critical intervention elements for young infants at risk for autism. Participants will include 72 infants (aged 12 months to 21 months) and their parents who will be randomized to one of the two classrooms. Treatment will consist of two 3-hour sessions each week plus an additional hour of in-home training over 8 weeks with pre and post assessments and follow-ups at 4, 6 and 12 months to span a 12 month period of the infants' development. Primary outcome measures focus on social-communication and language abilities of the infants with secondary measures of parent interactions and electrophysiological measures to examine biomarkers of change with treatment as well as predictors of social communication outcomes. Since parents play a critical role in their children's development, an effective parent-mediated intervention with a focus on core deficits may result in better language, and ultimately, improved social outcomes for at-risk infants.