Pit bulls are so common around here that some call them the “Labradors of New Mexico,” so it’s worth taking a closer look at the nature of this infamous pet. But who holds the answers? Depending who you ask, pit bulls are a dangerously vicious type of dog, they’re perfect darlings—or they don’t even exist.

That is to say, they don’t exist as a distinct breed. “Pit bull” is a term without an official definition, more slang than scientific identifier. Almost any mutt with “bully” qualities can be considered a pit bull, including the offspring of Staffordshire terriers mixed with a wide range of other breeds, lumping together a pretty diverse pool of puppies. Many mutts of unknown origins are misidentified as pit bulls based on their appearance despite lacking even a drop of terrier blood.

But does it matter which blood flows through a dog’s veins? Are certain breeds really more violent than others?