I'm not aware of another thread on this topic, but please merge if there is one. It seems like a good idea on the site to have a thread that examines research done to support or debunk MBTI as a system. I'm never entirely certain what to make of the system, and am looking for a clearer picture about its claims to being accurate. The purpose of this thread is to include research that supports the system as well as research that criticizes the system.
Here is one page I encountered about research done on MBTI.
Nowack, K. (1997). Personality Inventories: The Next Generation. Performance in Practice, American Society of Training and Development, Winter 1996/97
The National Academy of Sciences committee reviewed data from over 20 MBTI research studies and concluded that only the Intraversion-Extroversion scale has adequate construct validity. That is high correlations with comparable scales of other tests and low correlations with tests designed to assess different concepts. In contrast, the S-N and T-F scales show relatively weak validity. No mention was made in this review about the J-P scale.
Overall, the review committee concluded that the MBTI has not demonstrated adequate validity although its popularity and use has been steadily increasing. The National Academy of Sciences review committee concluded that: Ďat this time, there is not sufficient, well-designed research to justify the use of the MBTI in career counseling programsí, the very thing that it is most often used for.