Final answer:
Random developmental stages are not a characteristic of a social system, as these systems have structured development based on their cultural values, specific functions, and organizational structure.
Step-by-step explanation:
The characteristic that is NOT a feature of a social system is D) Random developmental stages. Social systems are structured and function within certain norms and rules, thus their developmental stages are not random. Social systems are defined by their cultural values, having specific functions, and a certain structure or organization. Each part of the system contributes to the whole, operating in accordance with established norms which guide how the individual parts interact and work together.