Question
Retrievers get their name from being excellent hunting companions, just as Shepherds are excellent herding dogs. However, the modern pedigree breeding business selects dogs for beauty and temperamental suitability for dog shows. As such, it would appear that pedigrees should begin to lose their original character traits. Both the Rhodesian Ridgebacks my family has purchased have been incredibly friendly and trusting of strangers (much like Golden Retrievers) and a little timid. They are not the ferocious and fearless guard dogs dog books and Wikipedia would have us believe.
Recently, I found the following interesting comment by Konrad Lorenz, founder of modern ethology and a Nobel Prize winner, about the ways in which dog shows have altered dog breeds:
As I have already intimated, it would be quite possible for breeders to compromise in the choice of physical and mental properties, and this contention has been proved by the fact that various pure breeds of dog did retain their original good character traits until they fell a prey to fashion. ... ... Modern breeding of the Chow has led to an exaggeration of those points which gives him the appearance of a plump bear: the muzzle is wide and short almost mastiff-like, the eyes have lost their slant in the compression of the whole face, and the ears have almost disappeared in the overgrown thickness of the coat. Mentally, too, these temperamental creatures, which still bore a trace of the wild beast of prey, have become stodgy teddy bears. But not my breed of Chows.
(Konrad Lorenz, Man Meets Dog, Routledge: London and New York, 2005, pp. 86-87), quoted from here.
On the other hand, many websites (like this dog breed selector) and books suggest that each breed retains its own temperament.
Answer
Breeding for the show ring has most probably a large influence on the "working" characteristics of many breeds.
For example the border collie, is, in most cases not bred for its herding capabilities, thus selecting and strengthening that trait, but for the show (or agility). In fact breeders would in most cases not be able to recognise good or bad herders, as these dogs are not working anymore.
In the absence of specific selection, strong trait of character or physical abilities will slowly fade away.
On the other hand as more and more dogs are bred for their apparence, and not for their physical abilities, many genetic diseases or malformation are now "free" and they quickly spread in the breed. I'm think hip displasia and Legg-Calve-Perthes disease.
One more aspect to consider is this: in my opinion there is an important confusion as how behavioural traits, that were considered only recently (a century ago people would care much less about "dog being friend with children/cats", "can stay alone without barking", and many other behaviours that modern dogs should master), are associated with breeds, although these breeds never selected such traits.
Example: newfoundlands are good with children: this is only marginally an hereditary trait and to my knowledge, newfoundlands were never supposed to be bred to strengthen that. So at best, it is only a recent aspect, introduced to meet the new role of these dogs, mostly companion pets, but at the same time, this tends to dilute other traits their ancestors were bred for. I'm not saying this is wrong either, although in some breeds this allowed some malformation to emerge quickly, see my previous paragraph.
Last thing: many "encyclopaediae" with one-page breed description tend to state what one would want the breed to be ("golden retrievers retrieve and are awesome with children"), while the breeding reality is much more complicated. With time and breeding for the appearance and temperament only, the strong "physical" working capabilities (here retrieving) will fade and hereditary health issues are more likely to develop.
As an "easy to read" reference on the subject, I recommend the book "Dog Sense" by John Bradshaw which covers that topic in some length (among other things).
Answered By - Cedric H.