Individual differences in early attention are associated with later social, cognitive, and emotional development, and attentional deficits in the first year are associated with risk for developmental disorders such as Autism Spectrum Disorder (ASD). The First Year Inventory (FYI; Baranek, Watson, Crais, & Reznick, 2003) was developed to identify 12-month-olds at risk for an ASD diagnosis. The current study identifies FYI items that reflect aspects of early attention that might predict future typical and atypical social, cognitive, and emotional development. Using a series of theoretical and statistical methods, we developed 3 attention-based constructs from the FYI: Responding to Social Attention (RSA), Initiating Social Attention (ISA), and Nonsocial Sensory Attention (NSA). A database with completed FYIs was analyzed using these constructs to determine the strength of relations among items. Cronbach's alpha analyses indicated good internal consistency, and item distribution was further supported using a confirmatory factor analysis. Data analyses showed statistically significant relations between the scores on these domains at 12 months and subsequent social responsiveness scores at 3 years. Analyses demonstrating the statistical and predictive validity of these 3 FYI attention constructs support their use for innovative explorations of infant behavioral patterns that can be used to predict typical and atypical individual trajectories in the development of later social, cognitive, and emotional skills.