(Background:  “Facing questions about her gender, South African teenager Caster Semenya easily won the 800-meter gold medal Wednesday at the world championships. “)

“It’s something that’s gone on in track and field before, and it’s difficult because, in track and field, you want to be able to categorize competitors as male or female, but biologically, it’s not as black and white as you might want it to be for competition,” Epstein told co-anchor Chris Wragge.

“(The IAAF) used to do this regularly,” Epstein continued, “and they gave it up in 1991 because it’s not very clear-cut. They will do it when, you know, some of her rivals said rude things, you know, ‘Just take a look at her.’ She came out of nowhere, she blew everybody away, and everybody doesn’t like being blown away, so the IAAF had to respond some way, basically, so this is their response.”

Epstein added, “The reason IAAF got rid of (gender testing) and the International Olympic Committee … got rid it is because, in some ways, it’s kind of impossible. Genetically, you can’t even look at someone’s chromosomes. There are women who have XY chromosomes, which would normally be for a male; there are testosterone levels that are all over the place. Genitalia can be ambiguous or doesn’t determine sex necessarily. So, there really is no clear-cut way to tell.

“The medical community has said you can’t always tell the difference between a male and a female, so I don’t know how IAAF, unless they come up with an arbitrary standard, is going to tell.”