It's so obvious, this invisible thing? Seems to me the wishful thinking could go either way here, and you could build a whole imaginary castle of hidden innate abilities, since they're hidden.
Why do innate differences stop at the brain-blood barrier? Isn't it quite reasonable to assume that physical, biological differences exist everywhere in the body, since birth? A priori there's no reason for assuming otherwise.
There's enough evidence that intelligence is partially heritedary. It's also obvious that there are differences between people who dedicate themselves to their hobbies and profession, well beyond the 10k hours.
If it could the other way, why isn't there an endless stream of Einsteins and Newtons? Are all physicists lazy?
That "castle of hidden abilities" exists, BTW, even though it's usually focussed on short-comings. Our genes are quite hidden, and determine a great deal of our capabilities and lack thereof.
