I think that my own laid-backness might come partly from being a reasonably (I say reasonably...I'm still fairly neurotic) integrated/well-adjusted 6 - thus bearing some resemblance to a 9. I actually wondered for a long time if I was actually a 9.
I have the belief that truly "wound-up" people have a tendency to invite or create their worst fears, or at the very least not properly prepare themselves for what could truly go wrong.
For me, feeling like I'm aware of the possibilities is enough to allay fear. It's sometimes kind of like taking a twisted sort of pleasure in cynical or dark ideations rather than the more superstitious "worry-wart" behavior (like when, if you fear spiders, you seek them out or watch videos of them in a kind of dark fascination.) If you imagine the worst, there's no need to feel wound up.
When I met one of my friend's parents, they expressed amusement over my lack of a filter, and loosey-goosey (her words) behaviour.
But they don't get I am saying and doing everything INCREDIBLY self-consciously, and am constantly evaluating and weighing what I can and can't say. I present this facade of guileless verbosity IRL, so people don't realize how much I am hiding/twisting/omitting. I also put myself down and act silly/submissive/friendly so people let down their guard, all the while I never actually let mine down. I am spying on them, more or less. And my more controversial/outrageous statements are usually used to indirectly provoke people into tipping me off as to where they stand on something.
Writing this all out makes me realize how crazy I am. Honestly, I don't think I could stop being so calculating and self-conscious even if I tried. It's great in psychological warfare, but I can't enjoy life. I'm extremely self-conscious about appearing nonchalant.
Thats about right with me. I don't sweat the immediate stuff (money, people annoying me e.t.c). But I will worry intensely about deeper things, like mine and and others psychological well-being, on a daily basis.