I have been really strict with DD. Even when she was 3 or 4 and she said something to hurt another feelings, she had to go and apologize. She would be resistant, crying but I made her do it. And it pays off. Today at 6, she is very conscious of what she says can hurt someone and also she is resiliant about others trying to manipulate and control and will smile and walk away and play with others. Not that she won't play with those kids, because sometimes they are her favorites. But if their behavior doesn't line up with what is acceptable and respectful, she goes and plays with others.

Even more reinforced this with the physical. There was a girl in her preschool that was her best buddy who hit and kicked. The girl did it to her own mother. DD tried it with me and learned very quickly -- not.