Ultimately, the limits of any living thing is genetically determined, that is trivially obvious: blue whales are very bad at sipping nectar from orchids irrespective of the amount of practice they may put it. Somethings simply benefit from certain design parameters, some things from other design parameters. This is so obvious it barely needs discussion. It's also rather irrelevant and uninteresting to this thread. And those like Rob who are pursuing the idea it's all about "talent" are just espousing bar room prejudice.
Excellence at certain skills (like photography) where both the skill and the recognition of excellence are often arbitrary, fashionable or disputed is very different from simple measures like height, eye colour etc that are generally distributed as a bell curve with the majority clustering around the mean and an increasingly smaller percentage at the extremes. The idea that best photos are only produced by the greatest talents is ridiculous. Photographic skill isn't measurable in a simple sense. First of all, there's no fixed undisputed way of judging the "best" photographs, it's a matter of personal taste. Fashion, cultural traditions and any number of other things make declaring something the "best" to be meaningless.
Even if it were somehow possible to agree a universal ranking for photographs, how ever could we decide the reason why a particular photographer produced the "best" work? It's easy to declare your favourite photographer "a talent" but what does that mean (beyond you happen to like their work)? Production of a photograph isn't something that depends on a simple measure like how tall you are or how fast you can run, it is a complex amalgam of multiple factors, some related to the photographer, some to the means at their disposal for making photographs and some more to do with the audience than the photographer.
Even if we stick to just the photographer's contributions, how can we possibly decide which of the many factors a photographer contributes to the process are the cause of the greatness? Is there work the result of insights gained from suffering childhood trauma, or insights gained from long hours in the darkroom? Or maybe they had a friend whose style they liked and copied, worked on and developed and then brought to the wider attention of the world through the influence of a good agent? How can we tell, we always have incomplete knowledge about the mix of circumstances, politics, fashion, friends in high places, practice, talents and dumb luck that all play a part.
It is probably true that there have been untrained artists who produced splendid work at the first attempt because they have some instinctive visual flair; it is also true that great work comes as the end result of a lot of personal development and learning first. Many endeavours are mostly craft with a dash of inspiration, most aren't things that just spring fully formed from the ether (even if John Denver claimed he didn't compose songs, they just arrived fully formed!). Successful artists, like physicists, musicians, mathematicians and any other trade are often falsely stereotyped as 'genius' as if that were all that were required to explain success. In truth, no two people become successful in exactly the same way by exactly the same route and as the result of exactly the same abilities - and indeed lots of people are not recognised at all until change in the vagaries of fashion propels their previously ignored or overlooked work into the limelight.
Yes, genes set the absolute limits but they are very rarely the significant limits and anyone who claims that lack of talent is holding back their photography would do well to examine rather a lot of other factors before falling back to that one...
And here we go again: regarding talented kids, I spent some early school years in India, and one event that amazed me to the extent that I remember it still, was as follows.
Our maths master brought into the classroom a man, and a boy of around twelve years of age. The maths master wrote up a long list of multi-digit numbers on the blackboard in the form of a typical addition sum. This boy looked at the list, and without benefit of paper or pencil, almost instantly wrote down the total. He was correct, on every different such set of numbers he was given to face. So how would you classify that ‘skill’ if not as some sort of inborn talent? Devil-worship?
My wife, who coached me through a maths exam during an engineering apprenticeship I had undertaken, could add up a shopping list more rapidly and accurately in her head than I could with a pocket calculator. Her Dad was the same. In school, she sailed through maths and advanced maths where I managed to go down thrice and only come up twice. In English, she was faultless regarding grammar but feared writing essays; I never gave grammar a thought and loved essays as a route to higher marks than the majority of the kids in the class. Again, where the benefit of those friggin’ 5000 hours: all of us brats had to put in the same time, few of us came out of it with similar abilities or desires or even levels of achievement.
Ray commented that there was a sense of superiority associated with the belief in talent. I don’t accept that as necessarily being the case. I see the belief in talent as a straightforward example of one’s experiences in life. Indeed, I have known several people who just ‘had’ it in their discipline; why should that be considered negatively? I would also add that that talent didn’t mean that they were especially intelligent or great in all the other aspects of their lives…