The above link is for the video for the puppy aptitude temperament test of a litter of Whippet puppies. I have a wonderful boy from this litter. For one year I had two, to closely follow their temperament, trainability, and strength of nerve and coping skills. Both had the exact same in whelping box experiences, both were tested at 49 days, and removed from the litter at that time. Both were raised together and had exactly the same experiences in my home. One was exactly who he showed himself to be at the time of the Positive Puppy Preview Working Dog Test, the other, sadly was also who he was during testing.
While testing is not considered an exact science, it has proven correct again and again when picking the right family pet, or high level competition dog. I so wanted one puppy to excel. He did not. It was the brother that I did not want due to size and color. Again, pretty is as pretty does. The brother with the "issues" was returned to his breeder for re-homing.