On a side note of self-bragadoccio, I am not genetically predisposed to playing the instruments I do (piano, guitar, violion). Typically, people who excel at these have long, slender fingers making it easier for them to make the awkward stretches that always show up. In contrast, my own fingers are shorter and stubbier than most guitarists, yet the claim I made in the other thread still stands - Of all the non-professional (professionals being: jobbers, people you see on tv, etc.) musicians I've encountered, only 5 or 6 actually exceed my ability by a signifigant amount, and maybe twice as many are on equal footing with me.

And it's essentially as Atmosfear said - a whole shitload of practice. I've been playing (admittedly as a hobbyist) for 6 years now, and when I started, I was practicing a minimum of 3 hours a day (sometimes up to 5) for my first two, two and a half years. at (3 * 730 = 2190 hrs) minimum of practice within my first two years (the days i didn't practice vs. the days I practiced extra roughly balancing out) is a whole shitload of practice time that most people don't get.

Is that because I am genetically predisposed? Not especially. I've been involved with music since I was about 3 years old, and every year I was in school, I was always in a music course of one kind or another. When I dropped out of high school is around the time I picked up the guitar, and I've been playing since. I haven't been practicing as much now as I was before (minimum of an hour a day, sometimes up to three, some complete missed days), but the amount of practice I get is generally maintaining my ability and adding slight gains - nowhere near the leaps and bounds I was making years before.

The real reason I've devoted so much time to it has to do with exposure, standing out because I excelled at it, given more time and encouragement to practice on top of my own selfish love of what I was doing. I think it's kind of chicken/egg about whether my love for making music comes from the fact that I'm good at it, or whether I'm good at it because I devote the time to it based on how much I enjoy it.

So I am pretty much on Atmosfear's side on this. While genetic predisposition helps, it only really stands out in the extreme cases - guys like Shaq who develop to a massive 7'1" gain advantages from being so tall/strong, and tend to choose fields where those talents will excel. But that's only the extreme cases - the average person will become an outstanding success in any field they actually apply themselves to. There are preferences based on exposure and encouragement at a younger age, but inborn talent is less important than is being stated in this thread.

P.S.: I am not trying to be conceited saying I'm good at the guitar - there are plenty of people who are significantly more talented than I am. It provides an apt example of how practice and dedication to any skill set will cause a chain reaction that causes one to succeed there, but the key in the majority of these cases is the sheer amount of hours the practitioner devotes to that skill set that makes the real difference, not a genetic disposition. Genes cause subtle differences, but rarely make a big difference.