I totally agree that it is how you bring up a dog as to whether it will be aggressive, but it is also genetic, Pitt Bulls as far as I am aware were bred for fighting, but please do correct me if I am wrong, The Japanese Tosa is also bred for fighting and the 2 other breeds which I can't spell, they were all banned for that reason, so that in mind we should no longer have any of these breeds in the UK or cross breeds of this type as by law existing Pitt Bulls in this country should have been neutered, so by now they would have died out naturally in this country, therefore we would not be in the situation of possibly euthanasing innocent dogs, which incidently breaks my heart just thinking about it, and can only imagine the heartache the owners of these dogs will have to go through.