This randomized clinical trial is designed to address Autism Speaks’ priority of developing and evaluating novel interventions for core autism symptoms. The study will assess the efficacy of a novel intervention targeting core deficits of social orienting, face processing, understanding others’ action intentions, anticipating others’ actions in social contexts, and engaging in socially synchronous behavior. Specific aims are to examine: 1) malleability of social cognitive deficits; 2) treatment effects at bio-behavioral (eye tracking) levels, reflecting improved social information processing; and 3) moderators of intervention effects: bias to social stimuli and biological human motion preference. Children aged 24-30 months with autism spectrum disorders (ASD) will be randomized into the Social Enhancement Intervention+Parent Education or Parent Education only condition. The Social Enhancement Intervention emphasizes child initiation and self-generated action, which are linked to cognitive, social, and language development. Three major intervention ingredients designed to heighten attention to social stimuli include: 1) child-directed input characterized by repetitious, high amplitude actions and facial expressions; 2) providing children with input and action-based experiences characterized by audio-visual synchrony; and 3) self-generated engagement with face components through specially selected toys and face images. Behavioral and biobehavioral outcome measures will be administered at pre- and post-intervention, and at 5-month follow-up. It is expected that treatment effects will be greatest on behavioral measures, with modest gains on biobehavioral measures. Greater treatment response is expected in children with greater pre-intervention bias toward social stimuli and preference for biological human motion. The findings promise to shed light on whether improvement in social functioning represents compensatory mechanisms, or also occurs at more automatic levels of information processing, indicating neuroplasticity of typical mechanisms. One study outcome may be the establishment of an intervention that enables children with ASD to more effectively and efficiently process social information, improving social success and quality of life. Thus, a preventative intervention would be available, thwarting the tendency of children with ASD to miss relevant social cues and enabling the use of such cues to elicit more social learning opportunities for themselves.