Final answer:
The three categories of common group roles are task roles, social-emotional roles, and individual roles, each contributing differently to group dynamics and function.
Step-by-step explanation:
The three categories of common group roles identified by early group communication scholars are task roles, social-emotional roles, and individual roles. Task roles are associated with achieving the goals of the group. Social-emotional roles contribute to the morale and cohesiveness of the group, while individual roles tend to focus on the needs of the individual, sometimes at the expense of the group. These roles were recognized as essential components of group dynamics, impacting how groups function and the outcomes they achieve.