What amazes me is that there are a lot more sociopaths walking around out there than most people realize, and the main reason for this is due to the fact that sociopaths are master manipulators. They have an uncanny ability to lie convincingly in order to get what they want. I've seen different statistics on just how many sociopaths exist within our population, and the figures tend to vary from 1 to 5%. On Khan's blog, 2% is offered as an estimate, which represents 1 in 50 people. When you think about it, that's pretty scary. Most likely we all know at least one sociopath, if not more, and we may not even realize it.
Another point brought up in the post is that sociopathy is a kind of a spectrum disorder. There may be different degrees of sociopathy. I hadn't thought of that, but if true, it explains a lot. Someone might be slightly sociopathic, enough to hurt others with their lack of remorse or conscience, and yet easily able to fit into society.
To learn more about people who lack a conscience, what motivates them, how to identify them and deal with them, visit Adam Khan's blog.