All theories involve some traits, or characteristics, that have been correlated with some aspects of leadership. Certain traits are associated with leaders in leadership situations. That others posses such traits and are not leaders does not refute the evidence in this regard any more than does the evidence that not all leaders in all situations posses these characteristics. Some, for instance, have suggested that leadership is a trait that only need exist in the perception of others, particularly followers.
Trait theory is a more sophisticated, specific version of the great-man theory.
It states that certain clusters of characteristics differentiate leaders from followers, effective from ineffective leaders. These qualities, or traits, are assumed to be stable in nature. An effective leader in one situation is assumed to be effective in any situation. Reviews of studies of leadership all tend to show that no single trait or group of traits has been isolated that sets off the leader from members of the group. From these, he found 79 different leadership traits.