It's 99% about the breeding. Yes there are outliers but genetics Trumps how you raise a dog in most cases.
We had chows in the 80's and early 90's when they were a popular breed. Our female never threatened us and was good with most people but had a couple of neighbors she wouldn't let out of the car. We had a black male that started out sweet but grew very protective of my mom. If she was in the house we weren't getting in. My dad put him down after he attacked myself and my dad on a couple different occasions.
On the other hand we've had Australian Shepherds that would herd sheep and cattle on instinct. Our chows wouldn't look twice at the sheep or cattle.
My golden retrievers will chase a ball all day and I've taken my old male quail hunting and he would retrieve birds without any training other than chasing a ball. Our chows and Australian Shepherds wouldn't look twice at a ball.
It's 99% about the breeding and I wouldn't trust my kids around a pit bull because I understand that.