Leadership should be distinguished from management. Management involves planning, organizing, staffing, directing, and controlling, and a manager is someone who performs these functions. A manager has formal authority by virtue of his or her position or office. Leadership, by contrast, primarily deals with influence. A manager may or may not be an effective leader. A leader's ability to influence others may be based on a variety of factors other than his or her formal authority or position.
In the sections that follow, the development of leadership studies and theories over time is briefly traced. Table 1 provides a summary of the major theoretical approaches. Historical Leadership Theories | Leadership Theory | Time of Introduction | Major Tenets | Trait Theories | 1930s | Individual characteristics of leaders are different than those of nonleaders. | Behavioral Theories | 1940s and 1950s | The behaviors of effective leaders are different than the behaviors of ineffective leaders. Two major classes of leader behavior are task-oriented behavior and relationship-oriented behavior. | Contingency Theories | 1960s and 1970s | Factors unique to each situation determine whether specific leader characteristics and behaviors will be effective. |