The present article proposes a new developmental model of how young infants adapt and respond to complex contingencies in their environment, and how this influences development. The model proposes that typically developing infants adjust to an increasingly complex environment in ways that make it easier for them to allocate limited attentional resources and increase opportunities for positive learning experiences. Increased positive experiences with contingency lead to improvements in contingency detection, social behavior, and, ultimately, the development of social and communicative competency. Research relevant to the proposed model will be reviewed and analyzed. In addition, implications for atypical development in the case of autism spectrum disorder will be examined. Specifically, it is predicted that difficulty detecting and responding to increasingly complex contingencies in the environment would lead to particular deficits in interacting with the social world due to the inherent relative complexity of the social world compared to the non-social world. Furthermore, experiences with an unpredictable and confusing social world may lead individuals to increase their experiences with predictability and contingency through restricted and repetitive behaviors and interests. Limitations and areas for future research are presented.