Wouldn't it be great if you could get a dog with all the outgoing affection of a Golden Retriever, the intensity of a Border Collie, the protection skills of a Doberman, and the lapdog size and weight of a Pomeranian? Well, yes. And no. And lots of stuff in between. The genetics of it all say that we get what we get when we breed for specific traits, physical or behavioural, and we can't change one side without affecting the other.