Well for one thing, they would have to have the same obsessions. One of the things that distanced me from my father wasn't the fact that we weren't on the same wavelength - we were, whether we were Aspies or just Aspie-like NTs - but that I didn't share his interest in the Thirty Years' War, vintage cars and African explorers, while he thought the horror and science fiction stories I loved so much were a load of bollocks.