Richard, you are right that that *can* and does happen. I have been guilty of that myself, surprise surprise! <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> However, I think that in this case, the "why" is important to understand. The solution being proposed here seems to be to have Mom work the dog more. Sounds to me like she has, and that has not solved the problem. Understanding that Dad is a huge part of the equation and getting him to change his behavior is very important here, if the dog's behavior is to be changed. That is why the "why" matters in this case. Does that make sense?

I mean, I totally understand what you are saying about trying to figure out why a dog does what they do. This is especially true in training for sport or work.....WHY the dog drops the dummy short of the handler, or WHY the dog lifts his head off the track too much is not as important as knowing HOW to shape that behavior to be what you want it to be. But understanding WHY this dog is aggressive to Mom and not to Dad *does* matter in seeing how both Mom AND Dad need to tackle this problem......

Anyway, EM Sheps, hope you've gotten some helpful opinions.