This proposal seeks to understand the manner in which communication evolves in infancy. The importance of this concern is clear, since parent-infant communication is a major factor in the cognitive and social development of the child. The PI has rigorously developed a set of hypotheses which hold early communicative acts involve the use of actions whose functions were not originally tied to communication. The study will help to isolate how these originally non-communicative actions are reorganized into an operative communicative system between parent and infant. In learning about the basic building blocks of communication, the PI will help to identify patterns of behavior that lead to more, or less, effective socialization of the infant.