Yes, helicopter pilots
are different. I'm speaking mainly from a military perspective, but I believe it holds true for all rotary drivers.
In the past I was involved in the "streaming" of military pilots, that is, deciding whether they would go fast jet, multi-engine or helicopter (and I know the military system is different now!). Then the idea was the helo pilots were "spotted" off the course, and the rest divided on pure ability between fast and pointed and the rest.
So what selected a heli pilot? Generally maturity beyond their (young) years and an ability to think for themselves. As someone once said, "There's no navigator or fighter controller to tell you what to do, and there's no TAPs (approach plate) for every field and clearing in Europe!"
So maybe the ability (or desire) to be in a part of aviation where you can and must make more of your own decisions makes the difference. But as to whether that means "well-adjusted" I don't know.
Certainly not at the parties.........