Okay, I recently posted this in another thread in response to a question, and someone suggested that I add it to a new thread... here it is. What I've done is defined "Quasi" temperaments by selecting the types that would seem to be most similar to a particular temperament, excepting the actual members of that temperament.
Quasi-Rationals: INFJ, ENFP, ESTJ, ISTP.
Quasi-Idealists: INTJ, ENTP, ESFJ, ISFP.
Quasi-Guardians: INTJ, ENTJ, INFJ, ENFJ.
Quasi-Artisans: INTP, ENTP, ENFP, INFP.
Interestingly, you can quickly see from this that IS_J's and ES_P's are the most strongly concentrated versions of their respective temperaments, as they don't show up at all. Upon further inspection, you notice that dominant Judgment types (IP's and EJ's) show up once, while dominant N types show up twice. This shows that stronger N's typically tend to spread their interests across a greater spectrum, and have tendencies in multiple directions, while most S's tend to be more predictable and focused in their interests, and probably make better specialists in any given field. But more importantly, it shows that IN_P's and EN_J's should be the most concentrated versions of their respective temperaments, because the N element is submitted to T or F, making the "filtered" element of N that creates the division in the Intuitive temperaments in the first place more pronounced.
Given how we usually think of N as being more creative and innovative, and S as more stable and reliable, it makes sense that the stronger the S, the more stable their expressions/motivations would be, and the stronger the N, the more spread out their motivations would be. This explains why INxJ's are often confused about their type... INFJ's often have Idealist, Guardian, and Rational motivations to some extent. I noticed this myself several as I was trying to type myself by temperament, a common method. I found that I could find something of myself in all of the temperament descriptions aside from SP, which just stood out as, "No, that's nothing like me."
What do you think?