I know the Keirsevian so-called "Temperament Theory". It is a very simple theory which sorts the people into 16 types.
There are 4 basic dichotomies :
attentive I - E expressive
introspective N - S observant
friendly F - T tough-minded
probing P - J scheduled
and 2 derivative dichotomies :
pragmatic / cooperative = NTP NTJ STP SFP / NFP NFJ SFJ STJ
directive / informative = NFJ NTJ STP STJ / NFP NTP SFP SFJ
but, I still don't understand how NFJ can actually be directive, and NTP be informative. I think an NTP would actually be better at leading than an NFJ... (Keirsey, not MBTI)