I confess I don't feel I have much insight into why some people abuse and others do not, even when they may have been abused themselves. In my case I had one parent who seemed to like us children, though he left when I was eight. His influence may have been enough to make the difference between me becoming abusive and not. Then too, children are all different from the beginning, and will react differently to similar stresses. I know my brothers reacted differently than I did, and I was the only one to develop a diagnosed mental illness. I think small beginnings can grow to large differences in outcomes. But this is not very specific as to what really makes the difference.