[Yomotsu Risouka]

@TrailMix: I agree with your post in general, but...

You can spot introverts because they'll become more easily distracted by their own thoughts; tending to be the ones who "zone out" or "go dormant" for periods of time.

This particular example doesn't necessarily apply to NFP. The Ne+Te combination can lead to an NFP in an extroverted state seeming to zone out. It, uh... sort of happens a lot when I play certain tabletop games, haha. I'll get so engrossed in imagining my next turn that I lose track of everything else.

Another thing that makes it difficult to spot introverts is when they're loud around their friends. I, as well as a couple of my other friends, am an introvert, but can be incredibly loud and hyperactive when I'm surrounded by mis amigos. I have WAY more energy in a small social setting than I do in a larger one and I am intimidated by big groups. The smaller the group, the louder and sillier I'll be, and if people didn't know me outside of a small-group setting, they'd probably think I was an extrovert.

This, on the other hand, doesn't necessarily have anything at all to do with E/I. It can easily be an issue of social anxiety, which also affects extroverts.