Of course some breeds are bread for aggression. Unfortunately. There was a huge problem with aggressive rotties, and many other breeds. For instance, Dogo Argentino is forbidden in AU, yet, those dogs are fantastic, stable, lovely and great with kids. But some moron decided to breed them to fight (people and dogs). Similar with pit bulls. Any responsible breeder will carefully select for looks as well as for character and health. There are breeds that are "sharper" than other, but sharp is one thing, aggressive another. You can control sharp dog and turn its sharpness the positive way, but aggression = unstable and it's not easy to handle and to live with. To me anyway.