Your decisions will never be as rational for a family member as they will be for a stranger or even a friend. You can't train that emotional response out of you no matter how hard you try.

If I saw a stranger holding on to a live electrical wire, unable to release it, I would be looking for an insulated stick of some kind to knock it away or for the power shutoff. If it were my kid, my thoughts would be more like "How fast can I run and tackle them, hopefully forcing them away from the wire?" Much the same - I would be perfectly willing to throw myself in front of a speeding car to knock my kid out of the way, but maybe not so much for a stanger. Is it rational to jump in front of a speeding car? But would you really hope for restraint not to do that and allow your child to be killed without you even TRYING to help?

Don't beat yourself up mentally for things that you cannot, or really wouldn't WANT to change. Do your best to plan ahead and try to forsee a response for dangerous situations. Don't be an idiot, but don't freeze up and be scared to act. When the time comes for action, trust yourself to "just know" the best course of action - be it the rational one, or the emotional one. When it's your child involved things are just different. And yes, I always did the rational and well thought out response back when I was a paramedic tending to injured people. My safety before theirs. But that would not necessarily be so responding for my family. I realize that my rationality might be out the window and I'd just be winging it.

It helps when you have the training and experience to know a real emergency for non-critical things though. When my young kids broke their arms (they were always doing that!), they'd coming running into the house screaming bloody murder "My arm's broken!!!" Then I'd say, "Well, that's not so good. Why don't you come sit down here?" They were probably expecting a response more ... sympathetically hysterical. I knew better. They probably would have gotten the emotional/hysterical response for a harpoon through the head though. I don't think I could have controlled myself as well then!

Thanks for the tip.

"Deep survival" by Laurence Gonzales also covers what seems - to me, at least - to be an excellent summary of current knowledge about how we decide things. (I'm in no position to judge the hard-core scientific basic of his book). Very well written, too.