> (fortunately, most of us do not live in a feudalistic or caste-based or apartheid society, where this would be literally the case)

It's great that you agree with me about barriers, but you might mention it to the posters in this discussion who are explicitly making claims of feudalism and apartheid. Beyond that, my post gave a logical explanation for probabilities. I don't see where you provided a counter to that logic, or even addressed what I said. How is my statement about three generations, for example, countered by your claim about predicting mid-life expected income for a single generation?