This document discusses factors that influence relationship formation and models of relational dynamics. It describes how appearance, similarity, complementarity, reciprocal attraction, competence, disclosure, proximity, and rewards all influence why people form relationships. It then outlines Mark Knapp's developmental model of relationships, which identifies 10 stages of relationships from initiating to terminating. The stages include experimenting, intensifying, integrating, bonding, differentiating, circumscribing, stagnating, avoiding, and terminating. Relationships are constantly changing and rarely stable for long periods as partners move through these stages.