Dear god, I hope not. ISTJ as my future? Like I need to get any more boring....
No offense ISTJs.... except, dear god, we're a dull bunch!
What he notes is similarity in brain regions & processes, not demeanors/visible personality (because they still self-type & are identified as different types).... I suppose similar thinking can still lead to different behaviors & demeanors & conclusions (perhaps the same regions/processes are used in different ways, applied to different "problems"). Conversely, that's why two types within a temperament who don't share any functions can often come to similar conclusions & even share common traits.
My observation of older INFPs (in person) is they get more Ne-ish. They get kind of looser, more comfortable in their own skin, more open about Feeling.
So I think I'm headed for the bright lights of Ne-tropolis, not the SiTe morgue :crosses fingers:
Anyhow, I wished I had been able to ask a question. No one asked what I wanted to know. Oh well, maybe in the future. Some interesting stuff, still.