Ahh, I see what you did there ~_^
No, I agree with that, I couldn't tell by what you wrote initially what direction you were indenting that to go, but I figured the concept of "how human behaviour is relative to psychopathy" probably needed it's voice.
I'm kind of an hobbyist in this field of study, I've read all of Hare's books, Lobaczewski, et al. There's a lot to be said about "acting on impulse" as you described. Psychopaths typically have no ability to introspect whatsoever, so a psychopath with a lower IQ (read: petty criminal with no reform capacity) might think "I need money for drugs" and given any available opportunity, they might simply steal it from their roommate, employer, etc. The point here is that the thought process goes straight from Self Need --> Action.
If they're clever, or better apt at modeling human behaviour, they'll go through some process for getting what they want that helps ensure they're not exposed, but ultimately, it never crosses their mind that "what they want" might not be in the best interest of someone else, they'll only ever consider their own interests.
Yes, you're right as it pertains to this study, because there's no way to accurately gauge the person as a whole or any depth of the characteristics exhibited. The Hare psychopathy test can ONLY be given in very specific methods in controlled conditions with professionals, anything short of that should be discredited.
A quick note on trolling - I've been personally called a troll on countless forums over the years because I have the kind of personality that challenges ideas... but it seems that the last decade the concept of trolling seems to have gone from "instigating debate with no purpose (or for flamebait)" to "instigating debate (period)" because, hey, the whole thing is subjective anyway, right?!
Sigh... thanks obama : /