I honestly can't say whether nature or nurture is the cause of the statistics, but even when you cheese is and break pit bulls up into multiple breeds and reclassify them as mixes, the Numbers are simply overwhelming. If that's nature, we need to strictly enforce spaying and neutering legally prior to any adoption. If that's nurture, then we need to restrict adoption to specifically certified individuals who can prove they can handle the needs of the breed. I'm in favor of both, as a start. I think the humane decision would be to phase them out as a breed through enforced spaying and neutering. And automatically put down any dog that threatens a human, immediately.