At what point is a child NOT on the spectrum, but simply an introvert?
The world is undoubtedly less tolerant of introverts than it used to be. And yet there is, to my mind, a real difference between finding engaging with others a bit on the draining side, and lacking the skills to do it at all. One could see it as a matter of degree of introversion, but I see it also as a matter of skills.
I am an introvert but also usually reasonably effective at engaging others in social situations. I have that skill set. DS10 typically makes mistakes that annoy people in social situations, even when he is aiming to please. His personal radar is not naturally tuned for sociability, even though he is actually more extroverted than I am by nature and loves being with people. By nature, he has little sense of what will please or interest others. There's a real difference there.
but still, even though I don't think he'll end up with a diagnosis we're continuing with the therapies just in case. It's really such a tough call with kids this young and I wouldn't want to regret someday dismissing something just because I didn't think it was right.
I think that's wise. The therapies will build skills in areas where he needs them, regardless of whether you consider those areas to be a disability or not.
But back to the "not interested" issue ... When his Developmental Therapist noticed he's a lot more advanced in some areas she started bringing him more challenging puzzles and toys and he is a lot more engaged in all the activities she has for him than before.
Here is how it looked for us. In preschool, DS didn't participate in the activities that other kids participated in. He was busy building model solar systems and doing math. Lots of people told us he was too smart to engage with other kids, that they just weren't on his level. But over time it became apparent that there were two problems: not only were his interests very different from those of other children, but ALSO he lacked the skills to engage. Both of these factors were real and operating in tandem.
His interests allowed him to get away with not engaging, both by looking smart (meaning that teachers wouldn't intervene because seeing him do math was so exciting) and by intimidating other kids into staying away and watching from a distance. The interests were real, but they were also a means of coping with the lack of social skills.
Once we built the social skills through therapy, DS was much more able to engage with age peers, and actually enjoys it. It is a mistake, IMO, to think that gifted kids are so much smarter than other kids that it's okay if they don't engage in reciprocal relationships with peers.
YMMV, that's our experience.
DeeDee