"one having a violent anti-social pattern of behavior or mental attitude," 1930, coined or popularized by psychologist George E. Partridge (1870-1953) from socio- on model of psychopath (q.v.) .
Entries linking to sociopath
socio-
word-forming element meaning "social, of society; social and," also "having to do with sociology," from combining form of Latin socius "companion, ally, associate, fellow, sharer," from PIE *sokw-yo-, suffixed form of root *sekw- (1) "to follow." Common in compounds since c. 1880.
psychopath n.
1885, in the criminal psychology sense, "a morally irresponsible person," considered as mentally deranged; "one who obeys his impulses regardless of social codes," a back-formation from psychopathic.
The Daily Telegraph had, the other day, a long article commenting on a Russian woman who had murdered a little girl. A Dr. Balinsky prevailed upon the jury to give a verdict of acquittal, because she was a "psychopath." The Daily Telegraph regards this term as a new coinage, but it has been long known amongst Spiritualists, yet in another sense. [The Medium and Daybreak, Jan. 16, 1885]
The case alluded to, and Balinsky's means of procuring the acquittal, were briefly notorious in England and brought the word into currency in the modern sense.