During infancy, humans have a limited attention span, a limited working memory and an initial lack of social experience. Given these constraints, why are infants so socially competent and how are they capable of processing such complex social information? Here we present an information-processing hypothesis that may account for these early social capacities. We outline those aspects of the social situation that must be processed for the infant to respond in a socially appropriate manner. We also outline potential cognitive sequences through which this information is processed. We conclude that the infant uses social information to determine what is relevant in the environment and in doing so, the infant uses each successive aspect of the social world to filter the overall amount of available information to a manageable size.