True, but with the changing of temperment, we'd have a fish similar to a guppy. There'd be none of that temper and spark that we (or at least I) love. Plus, it'd be more difficult to get them to flare, and if they didn't flare much, it'd be possible we wouldn't have have halfmoons. Along with that, their colors would be more drab.
I read an article written on bettysplendens.com about raising the fry all together with the father, and she had kept the boys in for a very long time with no agression at all. However, they were mostly cambodian and such. However, when she removed the boys and jarred them, they changed become a lot colorful and agressive (since they each had their own territory to 'defend') and flared a lot more. I do believe OldFishLady has sucessfully kept brothers from a same spawn together, but I'm pretty sure once a boy was removed that he couldn't be reintroduced.
On a side note, I did see and hear about the foxes, and I think it was really cool. A while ago I had done some research on them, and apparently the change in appearences and behavior was due to a drop in levels of adrenaline.