This I apply to traditional working dogs. I don't know enough about how temperament tests in molosser puppies turn out. What is a 'traditional working dog' vs. a molosser. Might be some overlap there. I haven't seen any puppy aptitude tests that claim to be breed specific. Furthermore, if the puppy aptitude tests were designed as an attempt to avoid mismatches between the owner's lifestyle and the dog's behavioral tendencies, why aren't they used more and why aren't more dogs successful in their homes? Drive traits are often used to make predictions about the later behavior of dogs. Some puppy tests and adult temperment tests are used to identify certain drive traits and then predict abilities/future performance of the dogs. None of these tests has ever been shown to identify these traits and to predict future behavior. Think about the high attrition rate of seeing eye dogs in training or explosive detection dogs.