My son Aidan is 20 months old. He is very sweet and very affectionate and loving most of the time. He also is very smart and is close to being potty trained, so he does have an understanding of things. Essentially he has never been hit as his sister for the most part is very gentle with him as are we. He is very aggressive at times though.
I watch a little boy and though it is less than when he first started, he still occasionally pushes or hits him for no apparent reason and seems to think it is funny. The other day I interviewed with a new parent and he practically terrorized her poor son by pushing, taking toys, and hitting. I found it very embarrassing.
Today I am at my wits end as he has been pulling the hair of his older sister and hitting her for fun. I have yelled and he stops but then does it again seconds later. I have lightly hit him back, which I think is ridiculous and it didn't work but I was desperate. I also did a few time-ins on the stairs, but again he would apologize immediately and then go right back and do it again. We practiced gentle touches and that did not work either. Finally twice I put him in a timeout in his crib for a minute and though that did seem to work for a longer period of time, I feel bad leaving him in there to cry. I know he knows what he is doing is wrong, trust me he does understand. He just seems to think it is fun to continue the behavior for some reason, like he loves hearing her scream or cry or something.