Characteristic features of autism include atypical social perception and social-communication skills, and atypical visual attention, alongside rigid and repetitive thinking and behavior. Debate has focused on whether the later emergence of atypical social skills is a consequence of attention problems early in life, or, conversely, whether early social deficits have knock-on consequences for the later development of attention skills. We investigated this question based on evidence from infants at familial risk for a later diagnosis of autism by virtue of being younger siblings of children with a diagnosis. Around 9months, at-risk siblings differed as a group from controls, both in measures of social perception and inhibitory control. We present preliminary data from an ongoing longitudinal research program, suggesting clear associations between some of these infant measures and autism-related characteristics at 3years. We discuss the findings in terms of the emergent nature of autism as a result of complex developmental interactions among brain networks.