This document presents the interaction adaptation theory, which attempts to predict communicative interactions between humans based on their expectations, requirements, and desires. The theory posits that when an individual's expectations, requirements, and desires align with another's, little adaptation is required for communication. However, if they differ, one party must adapt their behavior to communicate effectively. Humans feel compelled to adapt for social approval, to maintain identity, and to conform to societal norms. The interaction adaptation theory is useful for understanding communication in applied, intercultural, and interpersonal contexts, as it accounts for both similarities and differences between individuals and cultures.