" A striking result of this experiment was the consistency with which the subjects differentiated the roles of task specialist and socioemotional specialist (or process specialist). The task specialist typically took the initiative in conversation, defined the nature of the objective, and kept the discussion focused on the requirements of the task. His success might be measured by the extent to which he devised a viable plan of action and elicited sufficient agreement (not necessarily unanimity) within the group to realize that plan. The socioemotional specialist typically listened and responded more to others, endorsed their suggestions, encouraged their participation, and sometimes relieved tension with jokes. He was usually better liked than the task specialist. His success might be gauged as a function of the group’s ability to maintain a sense of corporate identity and purpose. Virtually all groups expressed these distinct functions, and significantly, they were nearly always performed by different individuals. "

― Walter Isaacson , Profiles in Leadership: Historians on the Elusive Quality of Greatness