I have found that if a parent is involved in RC, building, flying, and maintenance, then a young kid has a good chance at it. I have taught a bunch of youngsters, not one has finished. But in all of those kids, none of the parents were into rc so they didnt have the support at home that a kid really needs. My experience has been that kids around 14 and up tend to solo, stick with it for a year or two, then discover girls and we dont see them again. But I'm sure they'll show up later in life to fly again. One of my wifes uncles wants me to teach his 5 year old son. I showed them my sim and the kid loved it. I explained that it would help a lot to develop his eye hand coordination and thumb memory on the sim first, let him mature, and we'll do a spot check from time to time to see when he's ready. Daddy is starting to show interest in learning to fly too. Its really hard holding the reins back on them cause they discovered banana hobby and hobby king and got a bad case of the "I wants" and "That is cool" before they came to me. They wanted to do the standard routine, buy a warbird, learn to fly. It was fortunate they had me to talk to before he spent a bunch of money.
Edwin