In your experience, do abused people become abusers?

Some time ago, it came out that my ex brother-in-law had been molesting young boys, usually in his capacity as a Boy Scout leader. I asked, and was told that he had been abused by an uncle as a young boy. He served time, and eventually appeared on an infamous talk show, incognito, to tell the world not to trust people such as him, because they would continue to abuse in most cases.

More recently, an acquaintance left her husband of 15 years, and by default, left her four young children. She was not leaving for another relationship, just said that her husband was emotionally distant. At first she visited the children on weekends, but has had no contact for nine months now, not even phone calls. She is about a half hour away from them and has a cell phone, so no physical excuses make sense to me. She was neglected by her mother, and has deep unresolved issues about that. I just don’t get this!

Do you think that it is more common for an abused or neglected person to continue the cycle of abuse, or is that just a myth based on a relatively few examples.? I’d think that someone who had the experience of being abused sexually, emotionally or physically might be more sensitive to the feelings of others and more determined to avoid doing the same thing to someone weaker.

I don’t want statistics or “scientific studies”, just personal observation and experience.