Two friends and I were discussing this very question after our recovery meeting when I blurted out something that I had heard my grandmother say repeatedly of my grandfather. And in quoting her, I realized the answer to my question. My paternal grandparents were from the hills of Kentucky and though they moved to the Midwest, they never lost their Appalachian roots. Grandma often said that Grandpa would "screw a snake if it would hold still long enough." I don't remember what I thought or felt about this as a child but do recall the whispers about Grandpa's other family--the kids he fathered with another woman on the other side of the mountain.
And things weren't much better on my mother's side of the family. I recall the stories of her father's sexual exploits--his having sex with women upstairs while his wife lay dying of leukemia in the bedroom below. My grandmother, as the story goes, would change the dirty bed linens and throw away the used condoms the morning after. But both grandmothers stayed; both put up with men behaving badly; both wore the familiar mask of martyrdom and "suffered through." And that's how I ended up married to a pedophile.
In a graduate class on substance abuse, I wrote a research paper detailing predictors for substance use or abuse, particularly focusing on the quality of the parental marriage as a risk factor. I drew a genogram of both families and since their roots were in Appalachia called them the "Hatfields" and the "McCoys." Because addictions, even those related to substance use, are often hidden I identified anyone with a smoking habit as a potential addict. I analyzed four generations of two very large families and what I found was shocking. There was not a solid marital relationship on either side of the family in generations one (my grandparents) and two (my parents) and those prone to addictions far outnumbered those with no visible addiction present.