I really like what you're doing here with both the psych and philosophy. I've studied fairly extensively the MBTI and I think you have an interesting grasp, but there's a lot more to this than the letter ratings. Two other factors you have to consider are: How introverted/extroverted are they? and how much are they willing to flex their personality to fit into a group? Mechanics-wise I feel like the personality type should play into most non-physical skill checks, and the more you are on one side, the more able you are to analyze things in those terms, and the weaker you are at analyzing it in anyone else's. That's where I see the strong suit of continua is in RPGs, in order to become better in one area, you inherently have to sacrifice in another. Now, if you want to ignore the entire continuum thing (because I face the fact that you're more talking about character development than core mechanics) you might like to take a look at the Kiersey Temperment Sorter, and the Jungian archetype model. Both of these I think could be interestingly implemented into an RPG system (in fact, I'm trying). Anyways, good luck and I hope I've helped at least a little as opposed to mindless babbling.
Continua
I really like what you're doing here with both the psych and philosophy. I've studied fairly extensively the MBTI and I think you have an interesting grasp, but there's a lot more to this than the letter ratings. Two other factors you have to consider are: How introverted/extroverted are they? and how much are they willing to flex their personality to fit into a group? Mechanics-wise I feel like the personality type should play into most non-physical skill checks, and the more you are on one side, the more able you are to analyze things in those terms, and the weaker you are at analyzing it in anyone else's. That's where I see the strong suit of continua is in RPGs, in order to become better in one area, you inherently have to sacrifice in another. Now, if you want to ignore the entire continuum thing (because I face the fact that you're more talking about character development than core mechanics) you might like to take a look at the Kiersey Temperment Sorter, and the Jungian archetype model. Both of these I think could be interestingly implemented into an RPG system (in fact, I'm trying). Anyways, good luck and I hope I've helped at least a little as opposed to mindless babbling.