Try as I might I could find no evidence that female Capuchins are less aggressive than the males as pets. In the wild females band together as protection against aggressive males. Veterinarians are generally uncooperative in Removal of teeth and nails because they consider it cruel. Below are links for two articles about Capuchins.
http://en.wikipedia.org/wiki/Monkeys http://av.rds.yahoo.com/_ylt=A9ibyKR...atepets_2.html
BTW
I have seen female baboons regularly chasing and beating up male baboons. Female lions force male lions out of the pride and do all the hunting. My pet parakeet was de-feathered by a female parakeet and my pet canary by a female canary. Both flew frantically from one end of the cage to the other trying to avoid the aggression. Certain female spiders and scorpions devour the male after copulation. A certain venomous female snake has to be cautiously pacified by her suitor because if not--she will kill him. A certain female pit bull almost bit off an ear of a male dog when he made a pass. And last but not least, women are now regularly beating up men in films and are the indisputable queens of all they survey at home--and woe to him who dares say nay! Do I dare say "Nay?" Naaa! : )