hand flapping/shaking and any other tics or such are a self stimulus way to either calm or work your brain into a situation (yes its part of the spectrum disorders if there is no drug or other influences around), get comfortable and forgive yourself doing it and you can learn how to deal with things much better. I think Im at the stage where I just non chalantly do the tics and stuff and overextend it to alleviate any stress/frustration etc; without noticing to much