MBTI is a scientifically proven personality test. INTJ is one of the 16 types.
http://wikipedia.org/wiki/MBTI

Independent, innovative, logical and driven by the inner world of ideas and possibilities, the INTJ often appears to others as a quietly self-confident (and sometimes stubborn) critic of the status quo, convinced that reality can be altered, the future reshaped. Wherever there is a need for change in systems, programs, concepts or theories, INTJs will be working behind the scenes to reorganize and revise. This type's focused attention to the personal mission may be inspiring or frankly obsessive, depending on the observer's viewpoint or the success of the enterprise.
Introspective and somewhat shy, INTJs place their trust in logical analysis and intuition to guide their thoughts and decisions. More feeling types may find them chilly, and more practical types accuse them of being unrealistic, but INTJs take their cues mostly from those they recognize as intelligent. Often attracted to theoretical, analytical and methodological areas of inquiry, INTJs succeed in a wide variety of fields, from ones heavily dependent on mathematics and science to more philosophical, literary or applied disciplines.
INTJs are natural leaders, although they usually choose to remain in the background until they see a real need to take over the lead. When they are in leadership roles, they are quite effective, because they are able to objectively see the reality of a situation, and are adaptable enough to change things which aren't working well. They are the supreme strategists - always scanning available ideas and concepts and weighing them against their current strategy, to plan for every conceivable contingency.