Abstract: We introduce the concept of composite agents to effectively model complex agent interactions for agent-based crowd simulation. Each composite agent consists of a basic agent that is associated with one or more proxy agents. This formulation allows an agent to exercise influence over other agents greater than that implied by its physical properties. Composite agents can be added to most agent-based simulation systems and used to model emergent behaviors among individuals. In practice, there is negligible overhead of introducing composite agents in the simulation. We highlight their application to modeling aggression, social priority, authority, protection and guidance in complex scenes.