Researchers have long studied the effects of social presence and media richness on media choice and the effects of media use. This focus on social presence and social psychological theories has led to valuable research on communication. However, little research (either empirical or theoretical) has been done to understand the ways in which media choices influence the cognitive processes that underlie communication. In this paper, we present a cognitive-based view of media choice and media use, based on dual process theories of cognition, which argue that in order for individuals to systematically process messages, they must be motivated to process the message and have the ability to process it. We argue that the use of rich media high in social presence induces increased motivation but decreases the ability to process information, while the use of lean media low in social presence induces decreased motivation but increases the ability to process information. The paradox of richness lies in its duality of impact: from a cognitive perspective, rich media high in social presence simultaneously acts to both improve and impair performance.