Myers-Briggs is a good starting point. Not perfect, as it relies on the honesty of the test subject, but I found its a pretty good general indicator of a persons make up.
Myers-Briggs Type Indicator - Wikipedia, the free encyclopedia
This is a great book on the subject.
Please Understand Me: Character and Temperament Types: David Keirsey, Marilyn Bates: 9780960695409: Amazon.com: Books