Quoting statistics from various races, even at a college level, is stupid. The bottom line is that very few of even serious runners are training properly to come anywhere close to maximizing their potential. Additionally, very few people actually know how to make it hurt in a race. Most people just don't have the drive to push through the pain. I believe that I come from a pretty average family genetically. If I get injured, I can put on weight pretty easily, and I have a pretty large bone structure, so I'm never going to be able to be a 130 pound runner (at 6'0", I hit 3% body fat at 159-160). However, with a few years of running decent mileage with almost no training plan whatsoever, I have run under 16:10. I am not physically gifted whatsoever. My first 5k, after a few months of what seemed like pretty strenuous training, was a 24:30 or so (and I didn't have much weight that I could drop to make me faster). Hard work pays off, but people don't put in the work. I'd be honestly surprised if there was any able bodied male under 25 that couldn't run at least mid-18s with a few years of good training.