Any animal can turn and so can people. It's just part of being a living being that can and has to react in someway to outside stimuli. Fight or flight, nature programs us all with this.
Pits and bully breeds are stubborn, and part of that stubbornness is determination. Some won't give up if truly set at something. That's why their bites can be bad, not because of whatever myths there are about their jaws.
They cannot close them so tightly or lock them so that you can't get them open, but they (and any dog) will do their best when it's time to take medicine.
The breed loves to chew. It has to be directed to proper toys and when they're puppies, it's best to have them crated or be willing to lose some item of furniture (determined dog plays in here).
Once trained to listen you'll end up with a dog that really wants to please you. If you're mad at it you'll end up with a pouting pitty. Growing up, we had a male that would whine and cry if you were upset up him. If told to be quiet he would sit there and sigh really loudly and give you these horrible looks that seemed to be saying "you're so mean to me, how could you".
This was usually because we told him no and to go lay down.
We didn't have aggression problems at all. They loved cats... a little too much, cats tend not to like dog slobber baths.
Whenever we had kittens we'd have a horrible time keeping the dogs out. Every single pit we owned wanted to take care of the "babies" and would cry for them. All dogs were raised from puppies with cats in the household. I think it had a negative impact on the male dog... he acted a bit like a cat sometimes. He would try to circle around your legs and rub on you, tried to use the scratching post.
Our male had an unusual fear of water too, he was scared of puddles and would cry during baths. Another just hated the soap. And one was scared of bubbles, like the kind a little kid would blow...I never figured out why.
A few years ago I was visiting with my dad's wife. His dog had been left outside since it was a nice day and when we returned we discovered that she'd got a hold of a stick. I had to have my dad's wife hold her mouth open while I reached into her mouth and removed the piece of stick that was stuck inside her mouth between her teeth. The poor dog was panicked at this point and I still wasn't afraid to reach into her mouth.
So don't fear their jaws. Their anatomies are just like any other dog's.
They're like any dog really. There's responsibilities and you owe it to the dog to make sure it's trained and properly cared for.
I consider them a somewhat needy dog, they need your approval.
Some like humans and cats better than other dogs.
Stubborn (but less so than any cat
They're strong, if not properly trained to walk on a leash you will be dragged. With proper training some APBTs are entered into weight competitions - some of them can easily pull over 200lbs (it's amazing to watch!).
Don't expect them to keep out strangers. They may or may not protect you, but anyone wanting to walk into your home when you're not there may just be greeted by a wagging tail.
They tend not to show that they're in pain. They will quietly endure injuries and sickness, often while putting on a "happy" face - wagging tail, greeting you like normal.