Unfortunately that explanation is too simplistic. You laugh while you mock someone and they're disturbed by that. We also have many cases of gangs beating up ra

Unfortunately that explanation is too simplistic. You laugh while you mock someone and they're disturbed by that. We also have many cases of gangs beating up random people while laughing. We have phrases like "laughing at you" where the default assumption is negative, not positive. If laughter communicates "I wanna play", then laughing while someone is afraid, or sad, or disturbed actually communicates something very sinister: "I wanna play, and you're my toy". I suspect this angle is why in horror movies seeing playing children in odd contexts, or creepy dolls, or phrases like "wanna play a game" in Saw and so on is so effective. There's nothing more dehumanizing than realizing you're a plaything in the hands of a higher power that has zero regard for you as a life.