Lead probably played a part. Plus your father may of been replicating the people around him. Or your father and you may have different job expectations. Or(and this is probably true) you saw how you felt when your father wasn't involved and made it a priority for you to be involved in your child life.

There are a thousand reasons that may be. That's why single experiences are not evidence.

I'm not a scientist, I don't know what I'm talking about. I could be wrong, it's just a hypothesis based on my own observations. I'm just thinking there are probably societal factors at play also.