1. It is primarily an emotional thing
2. There are people grabbing them through the chute so it is a reponse to that
3. They see it happen in front of them so they follow the lead.
4. Men aren't as comfortable having some guy hold them or drag them so they keep walking.
5. I could imagine females have a slightly different physiological makeup that would make collapsing slightly more likely to be genuine.
As for the girls helping the fallen baylor runner, it is whatever. Does calling it sportsmanlike make the other runners who ran past unsportsmanlike? All I really think is that in no way should any of them be DQ'd. A DQ should be the result of something advantageous for you, or something that had a negative effect on something meaningful. So misplacing scoring runners or something. Officials tend to have no logical thought when it comes to Disqualifying athletes, especially in H.S or when Alberto Salazar is around.