but that's just it, genetics are kinda funny that way. You can breed two dogs and think you know what you're going to get, and not get it. You have to look at all the traits in both dogs being bred, look at their pedigrees, know good and bad traits of the dogs on their peds. You are not just going to breed a calm dog with a neurotic one and expect all the offspring to be in the middle. Genetics don't work that way. There is way more too it, and so much more that can even be discussed here, as there is just so much. One could discuss genetics for days, and still have barely tipped the surface. You can breed two dogs the same color together, and not get a single pup that color in the entire litter. It can and has happened. Now, if you were to breed a mild lab to a hyper lab, for instance, yeah, you may end up with one that is moderate, it all depends on genetics farther back than just the two parents, and which genes are dominate and recessive.
ETA: I know a person, one of my friends that also shows. She bred two Grand Champions together, one was even a Grand Champion in multiple registries. Both dogs tested great for their health tests, and both have solid temperaments. The litter produced 8 pups. In a 3 Generation Pedigree, there were 10 titled dogs (out of 14 dogs in 3 gens). They thought they were going to get the best of both worlds. Every dog has faults, no dog is 100% perfect. In this litter of 8 pups, 1 has become a show champion, 3 are still alive today, the other 5 have been euthanized due to health and temperament. Somehow this whole litter, just about ended up with the worst of the genes the parents had. Like I said before, even an experienced breeder who's been into a breed for 40 years, can't always predict what they are going to get in a litter. This litter I used as an example was produced by a breeder that has produced more Ch and GRCH dogs than anyone else I know. This breeder has produced many top 10 dogs in the registry we show in, and is very respected. They do a lot of research and planning before even announcing a potential litter.
Genetics are funny like that. Even in well bred dogs, some funny stuff can hide, you can never predict 100% what you're going to get.