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.