Marvel fans are brushing off their copies of the DSM-5 after Netflix got a little colorful with their description of Avengers: Infinity War. The streaming giant described the cosmic mass murderer as an "intergalactic sociopath," inspiring debate and laughs in equal measure.
The problem with calling Thanos a sociopath is that sociopaths are commonly considered to be people who lack remorse or regret for their actions. The word is used to describe people who are incapable of feeling bad about the ways in which they hurt people. Thanos may have wiped out half of the universe, but he's definitely shown regret about having to kill in the Marvel Cinematic Universe.
Fans "well, actually'd" a superhero genocide, laying down distinctions that probably mean little to the half of the universe that got vaporized.
Officially, there is no definition of sociopathy or psychopathy recognized by the American Psychological Association, but we can probably venture a guess that Thanos isn't typical when it comes to his ideas of right and wrong. It takes a special kind of person to kill half the universe in one go.
Beyond the back and forth over the meaning of "sociopath," plenty of Marvel fans just thought it was funny.