Quote Originally Posted by lungs View Post
I tend to think that sx firsts can be more fickle in their attempt to find and maintain that elusive spark, while sp firsts can latch on fiercely, more concerned with roots and a sense of "home" and continuity. (i don't think this translates into propensity to cheat or anything like that.)
That has more to do with what kind of attachment triad you are than instinct.
http://www.fitzel.ca/enneagram/ObjectRelns.html
Sx firsts are more aware of attraction and spark, though. That is what sx is.