Some definitely are. Different breed of dogs had different purpose. Some dogs where hunting dogs, other guard dogs and some simply companion dogs. Dogs like rottweilers and Irish Wolfhounds were used for protection, it is in there gene to try and protect their owner. My Labrador's typical response to an unknown person is to lay on it's back and wait for belly scratches. On the other hand, the way the dog has been trained and raised can alter these predispositions, but it's still in them.