Even if not everyone starts at the same point that doesn't mean they will continue to stay ahead. People operate under the assumption of a constant veclocity in

Even if not everyone starts at the same point that doesn't mean they will continue to stay ahead. People operate under the assumption of a constant veclocity in development. And that development is non-inertial (in the physics sense). The rate of development function could well be logistic or with an asymptote or some like - removing that insurmountable gap implicit in so many statements. We may all end up near enough (for all practical purposes) at the same endpoint if we all worked hard and performed necessary rotations and frame changes given our situations. The brain is very malleable. There is also the fact that people start at different places for different areas and that chooses where they end up specializing. And there is probably some self-fulfilling prophecy going on that trains people to avoid smarty pants subjects which are vital for developing rigorous thinking. why is it a matter of pride to be terrible at maths and technical subjects? or the fact of growing up with certain teachers and society all but directly informing you that certain races aren't up for certain more mathy subjects. I can certainly attest to that stuff messing up your ability to keep on when things get difficult.