This is a good, though somewhat light (being intended for the pop-psych crowd) description of just what a sociopath is, what makes them tick, how to recognize them, and how to avoid them. It's not full of gruesome crimes or case studies, because Stout's key message is that sociopaths, for the most part, are not psychotic serial killers. They are seemingly ordinary people who can live ordinary lives fooling most everyone around them. And if you do realize that someone is a sociopath, there isn't much you can do about it if they aren't actually doing anything criminal. Sociopaths all play dominance games and view other people -- even their own families -- as objects to be manipulated and used, so the only thing you can do is disengage, even if the sociopath is your own parent or child. The scariest and most heartbreaking thing about them is that they are completely incurable.
Stout's lengthy explanation of conscience is sometimes interesting, though full of a lot of speculation, blending as she does viewpoints from every field from religion and mysticism to evolutionary psychology. She tries to address questions like "What causes sociopaths?" and "What evolutionary advantage could there be in having no conscience?" (and conversely, "What evolutionary advantage is there in having
a conscience?"), but like anything treading the murky waters of evpsych, it's mostly speculation. The fact is that (according to Stout) 1 in 25 Americans is a sociopath, and this crosses all economic and social strata. Contrary to what you might assume, sociopaths don't seem to be produced by abusive or traumatic childhoods. She tries hard to argue that sociopathy is a combination of innate and environmental factors, and clearly there is no gene for sociopathy, but it does seem to be the case that sociopaths are pretty much born, not made. If there is any way to detect early warning signs that a young child might have sociopathic tendencies and correct it before it's too late, psychology does not yet seem to have figured it out.
Stout claims (without a lot of evidence, I thought) that sociopathy is more common in Western society. Obviously sociopaths have always existed in every society, but she argues that Western society encourages sociopathic behavior by giving rewards to "winners" even if they win through ruthless and unscrupulous means. I find this questionable; not that sociopaths can rise high in the political or business world (obviously they can) but that any other society is better at filtering out people without a conscience. There's plenty of ruthlessness and corruption in Asia, the Middle East, Africa, and even small tribal societies, so I really doubt sociopaths thrive less there than here in the U.S.
Stout ends the book with an attempt at a reassuring message that sociopaths really don't win in the end; that they mostly live hollow lives of perpetual unfulfillment and can never even appreciate what they are missing. This may be true, but I suspect a lot of sociopaths feel pretty darn self-fulfilled when they get what they want. Nice guys may not always finish last, but if you're competing with a sociopath, it's going to be an ugly race, and the evidence around us suggests we are competing with a lot of them.