In November of 1993 I participated in a Myers-Briggs Type Indicator analysis conducted by 'Consulting Psychologists Press Inc.' of Palo Alto, California.
 
The personality system represented is known formally as "Jung's theory of personality type" , first developed by Carl Jung in the early 1920's and more recently made into a practical instrument by Katherine C. Briggs and Isabel Briggs Myers. Sometimes, this system is referred to as the "Myers-Briggs Type Indicator" (or MBTI), but in a rigorous sense, the MBTI is a particular test vehicle for personality typing according to the system. This is widely referred to and used extensively by many organisations such as human resource departments and career counsellors. The MBTI test results indicated my personality type as:-- INTJ
A good description and full exploration of the personality types may be found on the Internet at: Character and Temperment by Keirsey
Here are portions from their "Portrait of an INTJ" I most easily relate to as an individual:--
 

INTJs are the most self-confident of all the types, having "self-power" awareness. Found in about 1 percent of the general population, the INTJs live in an introspective reality, focusing on possibilities, using thinking in the form of empirical logic, and preferring that events and people serve some positive use. Decisions come naturally to INTJs; once a decision is made, INTJs are at rest. INTJs look to the future rather than the past, and a word which captures the essence of INTJs is builder-- a builder of systems and the applier of theoretical models.
 
To INTJs, authority based on position, rank, title, or publication has absolutely no force. This type is not likely to succumb to the magic of slogans, watchwords, or shibboleths. If an idea or position makes sense to an INTJ, it will be adopted: if it doesn't, it won't, regardless of who took the position or generated the idea.
 
Reality is a crucible for the refining of ideas, and in this sense, INTJs are the most theoretical of all the types. Where an ESTP sees ideas as the pawn of reality, an INTJ sees reality as the pawn of ideas: No idea is too far-fetched to be entertained. INTJs are natural brainstormers, always open to new concepts and, in fact, aggressively seeking them.
 
Moreover, they always have a keen eye for the consequence of the application of new ideas or positions. They can be quite ruthless in the implementation of systems, seldom counting personal cost in terms of time and energy. Theories which cannot be made to work are quickly discarded by the INTJs.
 
INTJs have a drive to completion, always with an eye to long term consequences. Ideas seem to carry their own force for INTJs, although they subject every idea to the test of usefulness. Difficulties are highly stimulating to INTJs, who love responding to a challenge that requires creativity. These personality traits lead INTJs to occupations where theoretical models can be translated into actuality. They build data and human systems wherever they work if given even a slight opportunity. They can be outstanding in scientific research and also outstanding as executives who generate a plethora of implementations of ideas. Teamed with an INTP who is the architect of systems, the INTJ provides a dimension to an organization which insures that the work of the INTP does not gather dust on library shelves. INTJs live to see systems translated into substance.*