Quote Originally Posted by Atmosfear View Post
Unfortunately, this isn't the case. Being bigger than the other kids isn't a genetic predisposition as much as it is a product of birthday. Since childhood groups are stratified by grade cutoff ages, those who are closest to the cutoff dates can have as much as a full year advantage of growth over another. If the cutoff is January 1, and you are born on January 2, you are almost a year older than all the kids born in December. By the time this is distilled through continual selection processes, the only kids left are the ones near the cutoff, not because they had any better talent but because they signed up with a good birthday.
By the way this has all sorts of implications for the education system and has been a fairly prominent critique of the Ivy selection process. Gifted programs, for example, are naturally biased towards older children.