@jjj,
The root of our disagreement is in definitions. You're using a common definition of 'talent' which is not used in these books we're discussing. You're using 'talent' like most people use 'theory,' where theory=guess, or general idea, which is correct in popular usage, but not in scientific usage.
No, I'm not confusing my word usage, you or your precious authors are.
Talent and theory as words are not exactly comparable. One has a common meaning and a scientific meaning and the other simply has a common meaning.
I think this gets to the crux of the matter. So many disputes such as this arise as a result of different 'assumed' definitions of key words; in this case, talent.
The word 'talent' was used in Old English as talente, from the Latin talentum meaning unit of weight or money.
The word is now bandied around to refer to anyone who is particularly successful in any field, whether it be rock music, fashion designing, car racing or business acumen.
However, I wonder if those who argue that talent is not just an aquired state of skill above the ordinary, but something one is either born with or without, realise how arrogant their stance is.
Such a stance implies that
they know exactly what talent is and its origins. It also implies that
they can always recognise talent when they see it. Bear in mind that Van Gogh would have faded into oblivion had not the wife of his brother vigorously promoted his paintings after his death.
I also wonder if such people realise how negative they are being in asserting that 'talent' is something you either have or have not. Pompous, arrogant and negative, I would describe such people. Consider the many cases of people in history, who have later been recognised as having great talent, but who were informed early on by various authorities and contempories that they had no talent and should give up their pursuits.
One might wonder just how many people in history, of great 'talent', simply gave up because teachers and authorities, such as many posters in this thread, argued that talent was not something that could be acquired.
However, if one transcribes the generally understood meaning of talent to a more scientific phrase along the lines of 'inherited trait that may, by accident, be beneficial to an individual's survival or success', then one cannot deny that such traits exist. They are the basis of the Theory of Evolution.
As I understand, the process of Evolution relies upon both randon mutation of genes and the genetic variation resulting from different combinations of the male and female genes during procreation in life forms that have two sexes.
Is that 'talent'? When an individual in a hot climate near the equator receives a survival advantage because he's born with a slightly darker skin than his fellows, as a result of what one might describe as an accidental mutation; is that 'talent'?
If that's your definition of talent, then you are right. Talent is something you are born with or without.