What I have learned in my research of the breed is that they originally started experimenting mixing bulldogs and terriers to create a dog that was strong and courageous and agile at the same to time to apparently hold down the cattle to be slaughtered. Later on I think they continued breeding in defferent ways to create a blood sports dog not to fight another dog but to fight bulls and cows and other large game. That later was illegalized so they turned to putting them in a pit and having them chase and kill rats and whoever killed the most won. Hence the name PIT bull. After they I guess got bored they bred them to fight eachother. But these dogs were NEVER bred to be human aggressive no matter what you hear they were actually seen as very flawed bloodlines if they were aggressive towards people. Now people don't say that american bulldogs are considered pit bulls. The thing is that many uneducated people THINK that they are. The fact is that the reason why the "bite statistics" for pits is so high because so many different breeds are mistaken for pits. (American bull dogs,Bull terriers, Staffies, Amstaff's, cane corsos, presa canarios, and so many others) look similar because they are muscular with well defined jaw lines and so on. If people would actually get educated and now call every dog they see a "pit bull" then the stats would be no where as high. Hope I answered your question.