If the instincts are things you need to feel secure, then Sx-firsts need that one reliable person they can count on, and So-firsts need to belong to a group, and Sp-firsts need material resources.

Personally, as an Sx-first, I find I really do need to connect with one other person. I get pathetically desperate when I'm not connected. Since not everyone is Sx-first, and they can't understand why I'm obsessed with connection, I've tried to get them to understand by asking them how they'd feel (if an So-first) if the group they belonged to (at work, at school, at church, where ever) suddenly and publicly rejected them, or how they'd feel (if an sp-first) if they woke up and suddenly discovered that all their money is gone. Every last cent vanished without a trace from their savings and retirement accounts, and the debt collectors are here to evict them for non-payment, and their car is missing and their phone doesn't work.

That's kind of how I feel without a partner. My main problem isn't finding a dual, or a partner of any kind, for that matter. My problem is slowing down enough to take a good look at them.