So after watching the first three seasons of dexter (I was bored), I realized that my friends father, my friends brother and my friend are all textbook psychopaths (yes I looked in an actual textbook). They lack remorse, have an enhanced sense of self-worth and seem to be able to talk their way out of anything (even criminal charges).
It being present completely through that side of his family (in the males, females seem more succeptible to being deceived by psychopaths, oddly enough) suggests that it is genetic and thus has some form of evolutionary advantage.
In all of the universe there is only one person with your exact charateristics. Just like there is only one person with everybody else's characteristics. Effectively, your uniqueness makes you pretty average.