I think I have discovered how and why abuse gets propagated from one generation to the next. It's really pretty simple, once you get the idea, I believe.

You see a small child, and the parent or other adult abusing the child. The child has no perspective enabling him or her to understand why this is happening. If the abuse goes on long enough, the child will develop a more or less permanent state of fear/anxiety. Anxiety hijacks the brain to engage all its energies to cope with expectation of assault, with nothing left over to think clearly about anything.

The situation, unless altered, continues into adulthood, where stressful situations will provoke a panic reaction, and if no successful intervention takes place, the person will find his/her life increasingly failing emotionally. Feeling that there is no help available, no way of getting out of the mess, a person may well increasingly strike out wildly at anyone around -- if that person is a child, he or she has no idea why this is happening, and...

This will happen unless the person manages to get some insight into the mechanisms of what is going on. Without such insight, what we call abuse will continue from one generation to the next, without stop.

I finally figured this out (I think) by seeing this in myself, and in my family...