Sociopaths have a profound lack of empathy for the feelings of others. They lack the internal feedback system by which normal people monitor themselves. (Most people call this “conscience,” which is probably as useful a term as any.) Sociopaths do not have this and don’t feel bad about abusing other people. It’s not that they feel bad and ignore it—they don’t feel it at all.
The sociopath hides his or her difference. After letting it show a time or two—and probably being punished by a parent as a result—the sociopath covers up the truth and keeps it covered. But the reason for hiding it is not embarrassment (the sociopath doesn’t feel embarrassment), but because it hinders him from getting what he want.
Since sociopaths have no empathy for others, making use of normal people feels just fine to them. Likewise, they feel no remorse.
Empathy, as viewed by the sociopath, is a weakness, and he considers himself superior because he isn’t burdened by it.
Because they lack an internal feedback system, sociopaths are excellent liars. For example, they can often pass lie detector tests, since those tests register the effects of our internal feedback system, which they don’t have.
From They Walk Among Us by Paul Rosenberg