It appears that when people bring up the subject of their personality and behavior, pertaining to MBTI, they are told to disregard this because it is about the inner thought processes of the individual, and not their outward personality. Ironically, I have seen many people type on the basis of outward behavior, even exclusively, going by certain stereotypes of a type's behavior. To me it is logical that it would in fact influence, perhaps to quite a significant extent, these outward aspects of themselves.
If a multitude of people have very similar thought processes, such that they'd type the same in the systems, then these similarities in thought would lead to a similarity in behavior. They'd probably be more likely to act akin to those of the same thought processes, than those who's said processes are different. There is the influence of the environment, especially as one grows up, but who says that this isn't what creates, or greatly impacts, the habits of thought that we are scrutinizing too?
To repeat the thread question, to what extent does MBTI and the functions influence outward personality/behavior? Is there no influence at all, e.i. two ESFJs could have completely opposing personalities, moderately so, or a very significantly so. Thanks.