I have a bull terrier, which is really another version of a pitt bull. it is a long nosed version. He was very skittish when we first got him, evidently the former owner, a woman, must have beat him and kept him locked in a cage. He has always hated blonde women. Odd as I used to be a blonde. I turned him into a gentle dog after all these years. However, my ignorant neighbors see him as a threat. he is older now and not interested in roaming, but when he was younger he would take any opportunity to escape. He was not interested in people, just sniffing around. If a human would come near him he ran right home. Unless they were coming close to me then he went on alert. He has never bit anyone.
every dog, like every human is an individual. we are part heredity and part experience.