Yes, it's true they were trained to not bite people (unless guarding). Pit bulls, though often used for fighting, were also loved family dogs and usually slept in the childrens' rooms. Any dog that showed any sort of innappropriate aggression was killed.

I don't believe that there is a gene that is responsible for dogs attacking other dogs. There is definatly inherited dominance, which can cause a dog to act aggressively, though only an insecure dog will randomly attack, and insecurity is caused by lack of socialisation. Pit bull terriers are just that --- terriers. They weren't always used for pit fighting -- they were also used to bait bulls and kill rats and other small animals. I definatly believe that terriers keep their prey drive, but I don't believe that there is an inherited prey drive towards other dogs. The reason pit bulls have a bad rap as far as bites go is because they bite and then hold on and don't let go, just as all terriers too. Terriers have to hold on as long as they can, without holding on, they put themselves in danger. A rat terrier can be attacked by the rat, a bull terrier could be attacked by the bull, etc. So as far as instinct goes, I don't believe that there is a "random attack" instinct, but definatly the instinct to hold on or die.

I believe that all dogs need contstant socialisation and training. The only reason I think pit bulls need more is because, though their bites aren't as common as alot of other breeds, they are the first (sometimes only) to be made public. One bite from a pit bull causes ALOT of media attention and negative response from the public. A bite from a golden retriever, and hardly anyone cares. That's why I think it's more important for pit bulls (and other breeds with bad reputations) to get alot of socialisation -- not because they need it more than any other dog, but because if something ever does happen, the breed is automatically blamed.

In all honesty, I have never been bit by a pit bull. We groom them fairly often, and they have all been very sweet. However, I have been attacked by several golden retrievers -- we're not talking a nip, I mean the dogs seriously tried to rip my throat out. Tells you what the public really understands -- all pit bulls are bad of course, but buy a golden retriever from any Tom, Dick or Harry, and it will turn out fine because it's a golden retriever!