So it seems possible that the neurobiology for helpless, involuntary laughter, like my parents lying on the floor screaming about a silly song, might have a different basis to it than some of that more polite social laughter that you encounter, which isn't horrible laughter, but it's behavior somebody is doing as part of their communicative act to you, part of their interaction with you; they are choosing to do this.
Moguće je da neurobiologija bespomoćnog, nesvojevoljnog smijeha, poput onoga kada su mi se roditelji valjali po podu zbog pjesme, ima drugačiju osnovu od onih pristojnijih društvenih smjehova na koje nailazimo, što nije užasan smijeh, već je to način ponašanja kojim se nastoji komunicirati, dio njihove interakcije s vama,  a oni se odlučuju na to.