Who gets traumatized by witnessing family violence?

I sense a confluence of ideas. Or maybe it's just carrying things too far.

 It has long been one of my rules of life that people vary. Two kids grow up in an abusive household. One grows up to be a social worker and a fine parent, and the other is in and out of jail for spouse and child-abuse.

This study showed that the difference in whether kids who had seen family fights had symptoms of trauma ("(b)ad dreams or nightmares about their mom's and dad's arguments or fights; if thoughts of the arguments or fights ever just pop into their mind; if they ever try to forget all about the arguments and fights; and if they ever wish they could turn off feelings that remind them of the arguments and fights") was how concerned they were that "a family member might be harmed, the stability of the family is threatened, or a parent won't be able to care for them."

I've said recently that I'm beginning to think that a genetic difference between conservatives and liberals causes them to sense threats differently and to react to them differently. If this is the case, one's natural speculation after the study about who gets traumatized is that maybe it's the kids who grow up to be conservative who are more traumatized by seeing family violence. Maybe liberal, touchie-feelie, I-have-control-of-my-life-and-it's-all-going-to-turn-out-okay optimism protects against trauma after witnessing family violence.