I re-read what I said, LH, and I do understand it....you however, do not seem to grasp exactly what I am calling 'trivial'. I am NOT calling the totality of our life experiences that partially define who we are as humans 'trivial', but rather the dependence on that general totality as an explanation for specific variations in our belief system. It's 'sort of' true, but it doesn't explain much.
"Some people are mean" doesn't help much in trying to figger out why THAT person beat up that other person. I suppose you'd say, "Oh, all people have the tendency to be mean in them." (best I could do for quick metaphor) "pre-disposition" is way too general to argue a case in court, unless you can show specific examples...