Sorry, it's far too obvious that my Lab was "hard-wired" to fetch, for me to not believe it is more than possible for a pit bull to be hard wired for violence.
Yes. But, as has been exhaustively detailed here before, the term "pit bull' is a catch-all phrase that includes every short-haired dog that bites somebody, regardless of breed.
I have a golden retriever with the same kind of hard wiring. If around water, must swim out and bring something back. Repeat until human arm falls off from throwing stick. Repeat next day. Repeat until ice covers the resevoir.