...
I actually think a lot of what's been described here as introverted is highly flavored by Sp. I was on vacation for a week over New Year's, and while at the beach did a lot of reading on instinctual variants and discussing with a friend of mine (who is also introverted Sx/So). Since I've been home, I've been recognizing that stuff so much more IRL. It's amazing. I have a good friend who is a
Sp/Sx 1 Introvert and she's more the "shut myself in the closet" type (like [MENTION=7]Jennifer[/MENTION] mentioned), whereas my vacation friend and I drove from Chicago to Southwest Florida no questions asked, straight through the night, talked the whole way and had fun!
Instincts people, they matter!
Even what [MENTION=4939]kyuuei[/MENTION] mentioned about significant others that don't want to talk, adventure, and play all the time-- I see those characters as much more Sp first. Heck, I even know Sx last Extraverts who are really uncomfortable with one-on-one conversation for long periods of time (even if it's out and about and while doing things, which becomes like, "uh huh, uh huh. Hey look at that!").