Douglas McGregor, through his well-known “Theory X and Theory Y,” drew a distinction between the assumptions about human motivation which underlie these two approaches, to this effect:

1. Theory X assumes that people dislike work and must be coerced, controlled, and directed toward organizational goals. Furthermore, most people prefer to be treated this way, so they can avoid responsibility.  
2. Theory Y—the integration of goals—emphasizes the average person’s intrinsic interest in his work, his desire to be self-directing and to seek responsibility, and his capacity to be creative in solving business problems.

For McGregor, Theory X and Theory Y are not opposite ends of the same continuum, but rather two different continua in themselves. In order to achieve the most efficient production, a combination of both theories may be appropriate. This approach is derived from Fred Fiedler's research over various leadership styles known as the contingency theory. This theory states that managers evaluate the workplace and choose their leadership style based upon both internal and external conditions presented. Managers who choose the Theory X approach have an authoritarian style of management. An organization with this style of management is made up of several levels of supervisors and managers who actively intervene and micromanage the employees. On the contrary, managers who choose the Theory Y approach have a hands-off style of management. An organization with this style of management encourages participation and values individuals' thoughts and goals. However, because there is no optimal way for a manager to choose between adopting either Theory X or Theory Y, it is likely that a manager will need to adopt both approaches depending on the evolving circumstances and levels of internal and external locus of control throughout the workplace.