One thing absent on your comment about heritability is attraction: people with ADHD seem to be naturally drawn to people with ASD and vice versa. The fictional characters Wednesday and Enid in the Netflix series (as friends), or Xander and Anya in Buffy (as lovers). We balance each other.

The signals are not in the what but the why: ADHD stimming might involve tapping but the idea is to feel, not to soothe.

Not sure if "auto-immune disorders" belongs on your list of co-morbid disorders: there are some who think ADHD is an auto-immune disorder, like an allergic inflammation of the brain.

Your point about social deficits stemming from inattention or fear of judgement rather than lack of theory of mind are absolutely spot on. A typical ADHD social problem is misattribution or "mind-reading" - a person might yawn because they are tired, and my whirring mind reads it as "I'm boring them! They don't like me!"

This is very different to the ASD branch of the family tree: they don't understand that they're perceived as annoying or boring or rude, but feel bewildered and hurt when rejected by others.

The one thing that all of us have in common is that we have never been described by anyone as "normal".

"You're not mad," my colleague mused, long before diagnoses were a thing, "You're just really freaking weird."