There seems to be a general reluctance among people to acknowledge that people they know personally are sociopaths. When I explain what sociopathy is to people, they will nod their heads in general agreement about what I'm saying. But when I tell them -- on the rare occasions that it's true -- that such and such an acquaintance is a sociopath, I'm often met with a response along the lines of, "Oh, Joey? I don't think he's a sociopath. No, not Joey."
To these people sociopaths are exotic creatures whom they read about, not the ordinary-looking person they've had frequent contact with and with whom they might have shared some laughs. They will often say something like, "Joey? Well, sure, Joey has a dark side, but I mean who doesn't? I certainly don't think he's a sociopath."
You can practically see the wheels turning in their heads: Joey? Well, it's not as if he's ever killed anybody. I don't think he even could, he just said the other day that taking a life was wrong. Yeah, he can be a little selfish and even self-righteous at times, but basically he's a stand up guy, I mean he's always talking about morality and stuff. And he just seems so.....ordinary. I don't think he could be one of them.
This kind of thinking is erroneous. One needn't be a murderer to be a sociopath. Serial killers are only a small sliver of the sociopathic population, those whose favorite sexual fantasy involves death. To them, your life is worth less than their orgasm. Most sociopaths enjoy ordinary sex, which means taking someone else's life is unnecessary. But their basic psychology is no different: your well-being is worth less than any small gain to them.
Also, just because someone has given you a compliment and talked about what a moral guy he is doesn't ncessarily make him either a fan of yours or a moral guy. Someone who talks that way may merely be manipulative. Compliments may be heartfelt, de rigueur, or false; you must judge from the context and the speaker which. But people who go on at length about their own integrity usually have none.
There is one group of people who are an exception to this tendency to disbelief: ex-wives. Roughly three-quarters of women with ex-husbands seem willing to ascribe sociopathy to them.
Something tells me the percentage with ex-husbands who actually are sociopaths is somewhat lower.