Due to my non salt-wasting CAH, I was SO large as a child (until age 12) that I often sought out older boys simply because they were the same size as me.  When I was 4, my best friend was 7.  I was very active, very physical, but no one ever complained about me be aggressive.  I was simply on the move all the time.  If I had been born in a later age, I might have been diagnosed with Attention Deficit Syndrome because I had trouble sitting still, but that faded by the time I hit puberty. 

When you observe your son, determine if he’s enjoying the tantric release of physical activity, or actually seeking to hurt the other kids.  One is being competitive, the other is being mean.  And there is a big difference.  If your son is simply competitive, then continue to help him find healthy outlets for his energy.  If he’s trying to harm others, however, that’s perhaps something for therapy.  Hope this helps.  I’ll be happy to answer any other questions you may have.  Take care, Eric