So far he has been a totally different animal from raising DS1. I don't know if he will end up typical or asd but I can say with certianlty that whatever he is, it is different from ds1. At this age ds1 wasn't walking, waving, only a few words, patty caking, or following commands. Ds2 is climbing, running, playing social games, trying to join in at (big brother's) playdates, playing appropriately with cars (makes vroom sound and pushes on track or floor for several months), gets broom and dust pan and tries to sweep, patty cake, kisses, says hi and name even for grandpa, will follow commands "pick this up and take to dada" or "put this in the box". Comparatively talking to ds1 at this age was like talking to a puppy.
Of course though anything sets my radar off so I wish he would quit the head banging and I wonder why he doesn't wave more- he does wave appropriately but not every day and not even if I prompt him. I haven't seen him wave in days despite me hand over hand prompting it. Same with talking- prompting rarely works but if dad was in the room he will drop everything and say "hi dada" and run to him. Does that make sense? Ugh I have been able to pretty much have a "what will be will be" attitude (most of the time) but I cringe when i see the head banging. I'm not looking for anyone to say your kid is/isn't on the spectrum just wondering looking for some commiseration guess from other mom's of two who hate that little teeny voice that says "why isn't he waving today...does that mean something?"
Re: When is head banging no longer developmental?
My YDS, whom I have no worries about at this point, sat on the floor about a month ago and put all of his blocks in a line. And as I sat there and watched him do it I had a pit in my stomach.
So yes, I probably over-analyze YDS. I have a video of ODS who was sitting on the floor lining up his blocks and I remember thinkig how cute he was being. But as you know, ASD is not diagnosed by 1 act or even a few instances - but a series of red flags that add up over time.
I also analyze other kids - I have a friend who has a 16 month old that I'd bet a lot of money will eventually get an ASD diagnosis - I haven't said that to her. She HAS asked my advice and at this point my advice to her was to call EI.
No advice on the head banging, no experience with that here.
Anyway, yes, I think a lot of Mom's feel the way you do.