I think we could come up with infinite factors that determine a given definition of success, that apparently aren't linked to genetics, but I also think for eve

I think we could come up with infinite factors that determine a given definition of success, that apparently aren't linked to genetics, but I also think for every such argument there's another one that bring genetics into question. For example you mentioned upbringing. So now image the two kids above are raised by the same family, with the same values; they're equally smart, maybe they're even equally dedicated but one of the two lacks ambition/passion and doesn't live up to his brother's success. Why's that? Again, maybe the brother has his brain wired to be ambitious and has a knack (read passion) for whatever he does that lets him be successful.