Magenta,
aeh has given you excellent advice, and my first reaction is also to reassure you that this is not unusual behavior for a 3 year old
The thing that really threw me in the beginning weeks ago was that the director flat out, point blank told me that this was "not normal for his age."
One thing I'd add though - it's easy for me, or for your babysitter, or for anyone who's not at preschool with your ds during the day everyday actually witnessing the behavior to say this is normal behavior for a 3 year old, and to draw the conclusion, based on your observations, that he's hitting because his behavior is essentially being rewarded. I'd just add that hitting is a form of communication, and it's possible he's trying to communicate something at preschool that he doesn't need to communicate at home or to his babysitter. That could be boredom, it could be something else. When you're working with his preschool teachers, be sure to not discount what they have to say about his behaviors - work with them to implement a plan such as aeh suggested, but also don't automatically assume that they are simply inept at dealing with a three year old who is hitting. They most likely have seen a large number of three year olds, and it's possible that when they say what they are seeing isn't normal, what they are seeing really isn't normal. Hope that makes sense!
Also think through his school day and what happens when vs when he typically has issues with hitting - you can ask the caregivers if he's more likely to hit throughout the day at random or if the hitting occurs during specific activities or at specific times. One of my children was being constantly pegged as a problem at her preschool and we were called in a number of times and it was implied that her behavior was "not normal" - but the behaviors they complained about occurred most frequently after snack or after lunch. We eventually realized she had food allergies, and her "abnormal" behavior was occurring because she felt miserable after she ate dairy, which we were packing in like crazy in her snacks and lunch. I'm not suggesting your ds has food allergies, just suggesting to look for patterns re when the hitting occurs and see what it might relate to.
I would also consider that, for a lot of gifted children, a preschool that is including things that are semi-preschool-academic like learning letters etc often isn't a good fit. I personally can't imagine that it's going to be easy for the teachers to find a way to give your ds the special time reward on an ongoing basis, unless it's a preschool with a small caregiver-student ratio. If you have any other options for preschool that emphasize experiences, play, Montessori, etc, it might be worth looking into.
Best wishes,
polarbear
