Sociopathy is an informal term that refers to a pattern of antisocial behaviors and attitudes, including manipulation and deceit, that often arises from environmental factors. Sociopaths may or may not be criminals.
In the Diagnostic and Statistical Manual of Mental Disorders (DSM), sociopathy is most closely represented by Antisocial Personality Disorder. It is important to note that sociopathy is not a formal diagnosis, but is often invoked in discussing people on the antisocial spectrum, who generally display callous behavior with little regard for others.
Sociopaths are often difficult to identify until one is very familiar with their behavior. Sociopaths are often manipulative, lie frequently, lack empathy, and have a weak conscience that allows them to act recklessly or aggressively, even when they know their behavior is wrong.