This document summarizes several theories of cognition, intrapersonal communication, and interpersonal communication. It discusses theories related to message design logics, communication accommodation, uncertainty reduction, expectancy violations, politeness theory, social exchange theory, the dialectical perspective, and communication privacy management. For each theory, it provides an overview of the key premises, assumptions, concepts, and predictions put forth by the theorists. The document is comprehensive in covering several important theories within the fields of cognition, intrapersonal communication, and interpersonal communication.