The MBTI Enneagram overlap
It is important to remember that MBTI and the Enneagram are two different systems explaining two different aspects of our thought processes and behavioral tendencies. For the most part, MBTI is trying to explain information orientation and communication through cognitive functions, while the Enneagram is trying to explain the underlying dynamics that motivates us towards our desires, and away from our fears. To grossly simplify, Enneagram steers us towards our wants and needs, while MBTI gives us the tools to orientate and communicate said wants and needs, both to ourselves and to other people.
However, there are some strong correlations between MBTI and the Enneagram, which has led to some unfortunate stereotypes and misunderstandings that might alienate a lot of people reading about any of the systems. To put it this way: based on what I want to call the MBTI Enneagram overlap, we try to explain too much of our desires through MBTI, and too much of our expression and communication style through the Enneagram. If you are one of the people with a not-so-common MBTI and Enneagram pairing, you might feel like neither of the systems explains you well, because we emphasize the stereotypes the high correlations imply way too much.