A few months ago my son went through a stage where he was hitting. It was mostly his sister and he would do it a lot and hard. She understood that she was older, and she didn’t want to hit him back, so she would stand there bewildered not knowing what to do. I tried all different tactics to get him to stop; asking him nicely, I would explain he was hurting her, show him that she was crying, I tapped him on the hand once to show him hot it felt. I I would say it gently and I said it more forcefully. It pained me that it was happening; first of all because I hated to see het get hurt and cry, but also because I know he is such a sweet boy; all children are sweet and all children are inherently good.I was also sure that she was provoking him in some way and that it is somewhat the nature or siblings.