“If you look at the most universal forms of laughter shared across species, when rats laugh or when dogs laugh, it’s often in response to aggressive forms of play, like chasing or tickling,” Warren told me (and, yes, rats can laugh). “Chasing and tickling are both the threat of an attack, but without an actual attack.” By this theory, a good comedian chases with impropriety and tickles with wordplay, but does not deeply wound the audience’s social mores.
