I'm also concerned about the "hard training" MMA and "ultimate fighting" entails. Most "striking arts" like Tae Kwon Do don't utilize joint locks. If I recall correctly, Judo doesn't use many joint locks either, right? And don't most (if not all) Aikido dojo have a *minimum* age for children to start training? Not only that, aren't they usually just taught the *basics*, and none of the "harsher" joint locks? I've also heard that joint locks can be harmful to a growing child's body.
However, my main concern can be summed up thusly:
Two of the kids interviewed in the video:
"... get in there and get it over with and beat up some kid."
"I can punch people and not get in trouble."
Pretty much speaks for itself.
...and *that* is my biggest problem with children doing "ultimate fighting". I'm all for children learning the martial arts - but only to learn *self-defense*, *self-discipline*, and *self-control*. NOT so they can learn to beat up other kids better.