Trait theories which assume the capacity of leadership is the personality acquired by nature, mainly concentrate on personal quality and characteristics. The successful leaders are always described as heroic, mythic with significant traits, such as charismatic, enthusiastic and courageous. It is based on the psychological level and discovered four characteristics around the Big Five personality framework which are ambition and energy, extraversion, conscientiousness and openness and high emotional intelligence. Trait Theory can predict leadership and evaluate the effectiveness of the leaders.
Although the trait theories play an important role in leadership in the early period, the scholars have discovered other approaches from different view which emphasized the behaviors of specific leaders is called Behavioral Theory. Contrary to the Trait Theory, behavior theory is built based on the assumption of which people could be trained as the leader by designed programs. This theory claimed that the effectiveness of the leadership could be controlled by training.
The situational influences in terms of the relationship between specific approach and situation also make contribution to the effectiveness of leadership recently, as the outcome of success is not as simple as only depending on the traits and behavior. Fiedler contingency model explains how the situation interact the leadership style. The leadership style and situation would be matched and evaluated via LPC questionnaire. Moreover, the Cognitive Resource theory developed by Fielder indicated that the low stress would positively affect the effectiveness of leadership and high stress would negatively affect the effectiveness. In Hersey and Blanchard’s research on cognitive resource theory, the Situational Leadership Theory gives the specific explanation of the effectiveness among the follows and leadership style and implements in practice, while limited by the methodology of the test, this theory cannot be fully proved. Path-Goal theory proposes the environment of contingency factors determine the leader’s behavior and influent the work performance.
A more supportive theory, Leader-Member Exchange (LMX) theory, proposes that the leader create the group and the in-group will have better performance. It means that the resource of leaders would benefit to predict better performance with the special privileges.
In summary, there is no doubt the traits theory is so important to the leadership effectiveness, and certain characteristics is related to the leadership style, the Big Five personality framework give more support for the theory. However, there are also some drawbacks which limited. Firstly, the judgment to evaluate whether the leader is effective or ineffective is too subjective and lacks of the support evidence. Moreover the theory is simply generated without clear descriptions for each trait. Finally, there are also uncertain factors in terms of the theory. For example, which trait is the most important and how it influents the leaders. The Behavior Theory discovers a new direction and gives the narrow indication of the relationship between followers and leaders but lacks of consideration of other factors. The new theories provide more specific situational factors, such as the level of stress, the situation of the task, the followers’ personalities. The LMX theory which is also contribution to the understanding of the effectiveness indicates how the followers influence the leadership performance.