Construction of agent based model systems is often difficult considering the dynamic and complex nature of real world problems and various implicit factors affecting their behavior. This presents a problem in building accurate and valid systems for use as decision support tools. In this paper, we present an approach for handling some of these factors, specifically acceptance rate, retention rate and social influence, and enable simulated social agent models to evolve in a dynamic environment.The objective is to achieve a more reliable behavior and outcome for the agents in the simulation, despite unpredictable environmental changes. The agents’ knowledge, in terms of their observed responses to the environment and corresponding outcomes, is captured in a semantic tree. A metric is used to detect changes in the environment and the threshold of response of the agent, thereby triggering the agent to adapt its decision tree to maintain a reasonable response beyond its historical knowledge. The results reveal the ability of agents to detect changes in the environment more quickly and with better accuracy, using a case study, and as a result learn to adapt by modifying their decision tree under the influence of considered factors.