What is "behavioral theory?"
In terms of business, behavioral theory is based on leadership skills. It has less to do with traits a person was born with, like intuition, and more to do with a leader's capacity to do or accomplish objectives. In other words, it is less about what comes to one naturally and more about someone's capacity to "act."
If success can be defined in terms of describable actions, then it should be relatively easy for other people to act in the same way. This is easier to teach and learn then to adopt the more ephemeral 'traits' or 'capabilities'.
The obvious benefit of the behavioral theory is that "leadership" skills can be learned, making potentially anyone capable of assuming this kind of role, rather than simply those few "born" to lead. Researcher's behavioral theory is developed by observing leader's successes directly related to actions. In the workplace, theory is implemented by teaching the skills observed.