Nobody doubts the effects of genetic selection upon pointers pointing https://www.youtube.com/watch?v=VjcTXNfc9RI or German shepherds herding, or labradors retrieving, or border collies working sheep:
Genetic breed instincts are apparent as early as a few weeks old, as the videos show. So, why is it so taboo to admit that pit bulls, and similar breeds, were selected for a lack of communication skills and response to other dogs' submission signals, the tenacity to stick with what they're doing, an impulsive urge to pounce on other dogs (or smaller animals) and enjoy combat, and the trademark terrier grab-and-shake ("kill shake")? THIS is what you may need to compensate for, if you lose the genetic lottery and bring home a pet bully breed who still has some of the instincts they were originally bred for. It's important to teach GREAT impulse control and obedience to humans, and to have bomb-proof fencing so he can never roam the neighborhood.
Videos of tiny pitbulls showing the same level of breed-related instincts found in other breeds:
The GSD pups are all about communication --they send out a ton of body language, they're vocal (which is generally a sign of posturing, vs a real fight), the others respond to the posturing, they use no more force than necessary. Now, contrast that to the bully breed videos--pups grab on hard to another pup, stay latched on, are silent (or growling, but not barking), not trying to communicate, the other pups are just as eager to fight--even with nothing to fight over--and, they practice the 'terrier grab'/'kill shake' move for maximum damage.
Somewhere in between the other two, check out these tenacious little Maligators! (Belgian malinois) They are ready to work, right out of the gate! https://www.youtube.com/watch?v=ahgRChikBc4 Most working dog folks will tell you, Malinois are not casual family "pets".
Genetics sets your STARTING POINT. Where you go from there still has a lot to do with you...but make no mistake, NO breed is "just like any other breed". That's the whole point of breeds.