I am keeping my aggressive 4yr old at home mostly. The only place I take him out is places like temple so that there very few children present for him to hit unprovoked. If I take him to malls and on seeing a kid his age or younger he hits but some Singaporeans in mall make it worse by shouting directly at him....inciting him more. I wish they would just pass by and let me calm him or control him. I know nobody likes their child to get hit but if only they try to understand. May be it's asking for a lot.

Aggression is one of the ways a child can express himself. Frankly speaking, you need to look into what causes the aggression. Is he feeling neglected so he gets aggressive just to have your attention? Has he been exposed to violence too often? Has he been subjected to any form of hurt or bullying? Did a major incident happened to him that causes a change in him to be aggressive? Keeping him at home is not a solution, unfortunately. Humans need interactions. It could be that he has difficulty relating to any persons and that will require more professional helps.