The integrative approach is almost always used in real world leadership. No leader succeeds solely on the basis of traits, solely on behaviors or solely be adapting to situations. Leaders use all of the tools at their disposal. Consider Apple under Steve Jobs. Jobs had some fantastic traits as a leader, particularly with respect to his vision for the company, its products and how society would use those products. But Apple never succeeded solely on vision. Jobs' behaviors served to reinforce his vision and the corporate culture. His formal and informal power was constantly leverage to make the company better. He used power in dealing with suppliers, partners, and consumers as well, all of which has contributed to Apple's success. The only approach not used at Apple under Jobs was situational leadership, because the company never really changed its leadership style to fit the circumstance. But like any good leader, Jobs used a number of different...
Any theory of leadership that focuses solely on one set of characteristics at the expense of others is failing to understand the total package that was Jobs' leadership. When you look at other companies it is the same thing. Fred Smith runs FedEx by balancing his own power with the power of other top executives at the company -- he gives them room to stretch their wings. Apple would never do that -- but Smith is a Marine and thus values a balance between letting great people do their thing, and building a tight-knit team that functions well together. So his behaviors and traits both work along with a nuanced understanding of different uncertainty conditions. It is a completely different leadership style than Jobs, but both were hugely successful. Only an integrative approach to studying leadership can truly allow the student to comprehend the subtlety, complexity and nuance that comprises modern leadership.
