Myth #3: Bully breeds are prone to locking their jaws, and have a stronger bite than any other dog.
Stories of bullies’ super-strong jaws might make great horror film fodder, but science doesn’t support them. Research conducted by Dr. I. Lehr Brisbin at the University of Georgia shows that bully breeds don’t show any mechanical or morphological differences in jaw structure when compared to other dogs — nor do their jaws come equipped with locking capabilities.
To explore the question of jaw strength, a 2005 National Geographic study measured force of bite for several creatures as pounds of bite pressure. On average, dogs exhibited about 320 pounds of pressure, while humans came in at 120 pounds and great white sharks at 600. The study also included a simulated bite sleeve test with a German shepherd, a Rottweiler and an American pit bull terrier. The pit bull actually registered the least amount pressure among the group, despite rumors that bully breeds can clamp down with an alarming 1600 pounds of force.