What the label means
"Pit bull type" is not one breed. It is a loose group of dogs that share some features, such as a broad head and a muscular build. Breeds in the group include the American Pit Bull Terrier, the American Staffordshire Terrier, and the Staffordshire Bull Terrier. Many mixed breed dogs get the label too, based only on how they look.
Studies of shelter dogs have found that visual breed labels often do not match DNA tests. So a dog called a pit bull by a shelter may have little of that ancestry, and a dog with no label may have plenty. That is one reason we focus on the dog in front of us.
These dogs descend from bulldog and terrier crosses made in Britain in the 1800s. England banned bull-baiting in 1835, and some people then kept bull-and-terrier dogs for dog fighting, which was also later made illegal. Handlers valued courage and strength, and also dogs that could be handled safely. The dogs reached the United States in the late 1800s, where they were farm dogs and family pets. Today they are family pets, sport dogs, and therapy dogs. See our Pit Bull type guide.
How any dog behaves depends on breeding, early experience, training, and handling, not on a label.