Gotta say. While i don't particularly come to lpsg for these kinds of threads. They do fascinate the hell out of me sometimes. Like the sheer lengths (no pun intended) men will go to treat sex like a sports car or scientific experiment is fucking vast. lol Not saying that's a good or a bad thing. Just saying...differences in throat size? Not in a million years would i have gone there.
Anyway, i don't think there's any considerable difference in people's throat sizes. And i don't think people's throat sizes contribute to anything. Not an expert in anyway shape or form but i would imagine gag reflex has much more (if not everything) to do with how much of a dick a person can deep throat.
To me it's like people being flexible. Sure, if a person reaches a certain age they're much less likely to be flexible or have the ability to become flexible but within a certain age range they can learn if they aren't already.
As far as i can tell it's a psychological (ha didn't forget the h this time) thing. Just like there are people who if you tossed them in a pool there's a chance they could drown...boy that got dark didn't it....there are people who somehow naturally know how to swim. And those who don't can be taught/learneded.