What do you think of this statement regarding nature vs nurture in dogs?

I think they're talking about "working" breeds specifically, not your little shih tzu house dog. Cattle dogs and herding dogs haven't had that purpose bred out of them by selective breeding for looks and docile temperament. I think most of the working breeds that I see in my grooming shop have very strong herding instincts. We had an Aussie who came in frequently and we'd let him be loose in the grooming room with us. He'd do figure 8's around our tables and didn't like us stepping out of the zone that he had set up. He was a show dog for a time when he was very young, but had never ever been trained to herd. Had someone molded that behavior, he would've been an awesome working dog. I do think it's very true that using the natural instict that any dog has to mold behavior is the way to go for training. We tend to only think of training in human terms, instead of trying to understand why dogs do what they do and their own unique psychology.