Kachi wrote:But that all seems to assume that the person values someone who is fully human to begin with. A substantial percentage of incarcerated criminals have some form of sociopathy, which is essentially defined by them not seeing value in people other than to be used for their own desires. Furthermore, no effective treatments have been found-- the operating theory is that it would be possible to pinpoint many criminals in youth based on the development of their brain.
Au contraire. Sociopathy, or Antisocial Personality Disorder, is classified in the DSM-IV, which is a publication for psychiatry, and therefore only lists symptoms that can be quantified; for example, lying, a disregard for societal rules and laws, recklessness, impulsiveness. It is easy to quantify a disregard for rules and laws--people break them. Generally, people who end up in jail have broken laws of some kind. Naturally many of them would be sociopaths.
Psychopathy, meanwhile, is not classified as a psychiatric disorder. It is a psychological disorder and can have whatever symptoms it damn well wants. These include the "not seeing others as human" as well as lack of empathy or remorse. This is a rarer breed, and while they are still overrepresented in prisons (as well as politics, law, and the media) it is certainly not near the rate of sociopaths.
Sociopathy is extremely difficult to treat, as you say (they are the kinds of people who will not seek treatment unless forced, and it often occurs concurrently with substance abuse, which makes prescribing drugs problematic); however, the symptoms usually ease with time. They tend to peak in the person's 30's and go down from there.
This is relevant because you seem to be advocating violence against sociopaths because "they are less human," but the truth is sociopaths may have respect and empathy for other people--just not for society at large. Meanwhile, psychopaths are a) much less common and b) may indeed need to be confined, but violence does not follow from that.
I was mainly just excited at finding a use for something I researched in Social Psych, though.