Yet more psycho-babble hocum. So much of the four temperaments overlap with solid, universal traits for the virtuous individual.
I see no reason why we cannot be all of these, or none of these.
We might as well pick Hogwarts houses.
As mere conjecture, the Rational appears most concerned with their own self. It seems like the place where we all begin, before allowing ourselves to be defined in a proactive towards others.
It's merely a base, from which other virtues must be cultivated. My mind may change.