THE SOCIOPATH
Sociopathy is typically characterized as something being wrong with a person’s conscience. Sociopaths only care about fulfilling their own needs and desires: they are selfish and egocentric to the extreme. They see others as objects to be used in fulfilling their own needs and desires. They fail to see they are causing any harm and in fact will typically believe they are doing something good for society. 

Some people believe the term psychopathy is interchangeable with sociopathy, but field professionals make a distinction between the two.  A psychopath is marked by aggressive, violent, antisocial thought and behavior.  Like sociopaths, they lack empathy or remorse; unlike sociopaths, they often seek to fulfill their desires through violence. A sociopath prefers to play games and prove his cunning over society.  That is not to suggest that a sociopath will always choose not to engage in violence.  On the contrary, because their willingness to fulfill their own desires and their lack of emotional connection with others, they are much more likely to commit a violent act against another than most people in society.

The distinction between a sociopath and psychopath by field professionals is usually more based on the (lack of) nurturing by parents than heredity.  Lykken (1995), for example, clearly distinguishes between the sociopath (who is socialized into becoming a psychopath) and a “true” psychopath (who is born that way).  However, this may only describe the “common sociopath,” as there are at least four (4) different subtypes:

common – characterized mostly by their lack of conscience
alienated – characterized by their inability to love or be loved
aggressive – characterized by a consistent sadistic streak
dissocial – characterized by an ability to abide by gang rules, as long as those rules are the wrong rules.