Youngest is probably the one I'm most concerned about with that as he has the worst social skills (his lack of opportunity and ability to develop them further is of course entirely my fault and absolutely nothing whatsoever to do with him actively rejecting and refusing literally every single group activity I've tried to get him interested in). But all his autistic markers were on his social skills (he was one marker short of the whole diagnosis).
There'll be that and anxiety and stuff that contributes and then I don't know what everyone else's excuses are.