The difference, as with all synonyms, is in context and conversation. Statistical manuals/guides both national (DSM) and international (ICD) will offer the array of symptoms describing the sociopath, the psychopath. Situations in which the deviant is committing a heinous crime against society or individuals will likely have the "socio" term used to emphasize the social tragedy inherent in the actions discussed.Whereas psychopath will likely rear its head in discussions of diagnosis and origin-emphasizing the "psycho" element as though naming it renders hope of tangible control. That is not to say that helping professions need draw a line at helping the sociopath/psychopath, by no means. Drawing a line means entering the realm of no conscience: no moral obligation to another. The hypocrisy would move well past irony.
So, then, why are these disordered persons classified/labeled/treated? For the sake of the million to one chance that has a person buy a lottery ticket, donate funds for a cure to terminal disease, and go on living another day despite despondent circumstances...HOPE. Antisocial attitude, moral deviance, and criminal behavior cannot simply be written off. Everyone is someone's child. So the labor to classify to support the labor to diagnose to support the labor to research to supplement the labor of treatment...for what may be able to help one and so spare many.
But reality will always dictate the safety of many over any one individual, Aristotle labeled such a community successful. What Aristotle called the Golden Mean is to encourage behavior that varies not too far to any extreme so that life will function as smoothly as possible. An extreme, especially when it ventures into the criminally extreme at a human expense, then demands action and regulation.
The work lays in the hands of the law givers, the mental health workers, the police, the judges, the witnesses, the CSI, the lawyers... to prosecute, imprison, and monitor rehabilitation before considering parole of a sociopath/psychopath into society again. It really does not matter what fine line or statistical tick mark differentiates one term from the other until it is called upon for proof to be presented in courts requisitioning therapeutic files. It is because it takes a community to protect a community so that no individual, be it the psychopath or the victim, has no role that cannot be dealt with in due process until solid remedies for true rehabilitation and prevention are found.
For the future front-line warriors attempting both to protect the moral from the amoral and save the amoral from a shallow, lonely existence: realize when each term may be more poignant for use. But, more importantly, recognize symptoms and signs despite the rehearsed charm of the morally vacuous narcissist seeking to use each person as a tool. Specifically for the serial rapist, murderer, or thief, the PCL-R 20 point scale rating from 0-2 during a semi-structured, deliberate interview of how far from psychopathy a sociopath is after a given period of incarceration can make quite the difference in deciding parole and direction of future therapy.
For the young with conduct disorder to the older anti-socials, the DSM-IV and ICD 10 offer symptomology that should only be applied by a professional in diagnosis of a child/teen in order to apply appropriate treatment and utilize efficient intervention and hopefully remediation before any of these become to society a sociopath and to the individual an island of psychopathy.
H. Cleckley & R. Hare: Psychopathy checklists
Derek Wood, RN, BSN, PhD