HBS professor emeritus Abraham Zaleznik authored the 1977 Harvard Business Review article titled "Managers and Leaders: Are They Different?"
According to an article published Aug 13, 2008 in Harvard Business School's online Working Knowledge, Zaleznick still believes that,"Managers are oriented to process, while leaders are attuned to substance. Process is concerned with establishing procedures for solving problems, while substance deals directly with the problems at hand. Process is soon related to obsessive thinking and depressive emotional states, while substance energizes and draws on imaginative thinking. Managers tend instinctively to delegate; leaders like to get involved in working toward solutions to substantive problems."
Actually, I believe that establishing processes and delegating responsibilities are essential to growth of organizations while getting involved in problem solving can limit the growth of organizations.
Part of the issue here is the question of appropriate leadership style for different stages in organizations' existence. Managers, as Zaleznik defined them, are not entrepreneurs. They depend on leaders, as Zaleznik defined them, to found and nourish entities to a size which requires managers.
The issue for CI professionals is defining which competitors are run by leaders and which by managers and what are the implications for the stability of those firms and the predictability of their behavior.
Of course, these categories are useful tools for first passes at analyses; they force us to ask the questions to obtain more information and gain more understanding. They are not sufficient, but are useful.