http://www.realpitbull.com/temperament.html

If there was a manual describing ideal Pit Bull temperament, it would probably read something like this: "The Pit Bull is goofily friendly towards people--family, friends, and strangers alike. Known for its sound character, strong nerve, and great intelligence, the breed makes an ideal companion for households with children, while remaining strong and vigilent enough to protect its loved ones if need be. It is never necessary to embark on guard or attack training with this breed, as they are naturally attuned to their environment and intuitive about real threats. Although never aggressive towards people without real need, the Pit Bull is dog-aggressive, to varying degrees. The properly socialized and trained Pit Bull should not be an instigater, yet neither should he shy away from a challenge. The breed is known for its high prey drive, and so due caution should be exercised when cats, rabbits, domestic fowl, and other such animals are present. Aggression towards other animals should not be viewed as a fault, although excessive, uncontrollable aggression is neither desired nor correct. Aggression towards humans should be viewed as a serious fault.