i think of john and dadbert as both being autistic. not revolutionary or anything of course. but i picture john as particularly having like, the not-fun type of autism, i.e not able to hold down a job or do well in school, bad at regulating his emotions, big meltdowns, probably would need some kind of support forever under normal circumstances. oh, and i envision him as having a pretty strong autism accent, like some serious cartoonish affect going on. the type of guy who hits all his "T"s really hard when he talks, yknow.

dadbert is similar in some ways, different in others. he absolutely did not think he would ever be a father, and it is difficult for him with his and john's disabilities but he loves john more than anything and finds raising him to be very rewarding. i like to think that in his childhood he had some pretty significant speech delays, and he has a hard time with putting his thoughts into words, so talking isn't necessarily his strong suit. when he does talk, it is slow and deliberate, like he's thinking hard about each word he says.

my less detailed headcanons are that dirk has DID and caliborn has PDA-profile autism as well as developmental coordination disorder.