A questionable hypothesis
We have a lot of argument over the nature vs nurture debate. One side says you're the product of the environment, the other side of genes. A middle view says a little of both, but moreso a matter of one's specific adaptation to the environment in the context of other's competition on the basis of static traits. (my view)
What if there were two -- or even four -- different ways for types to emerge? One on the basis of environment, another on the basis of genetics, and two others on a completely different paradigm? This would mean one's type is inconstant in some people(?) and constant in others; and in others, a consequence of the need for harmony with society and one's natural predispositions...?