Personality preference and agile software development

Over the last few years I've become increasingly interested in the relationship between various aspects of personality and how comfortable people are with an agile approach. For example, there seems to be quite good correlation between people's MBTI and how well they cope with agility.

In terms of the MBTI (Myers-Briggs Type Indicator), strong Js (judging) are, in my experience, likely to be very unhappy with the late closure and uncertainty that XP requires. Ps (perceiving) on the other hand, are much more comfortable with XP (they are comfortable moving into action without a plan and planning on-the-go). I used to be very sceptical about MBTI (and other psychometric tests) but it seems to fit so well in a lot of cases. Of course, there are exceptions (I have read that Kent is an ENTJ) and we all have coping strategies for operating in our non-preferred modes. A team composed of purely strong Ps would present its own problems - they would tend to avoid making any sort of commitment.