I am not a behaviorist...(other more knowlegeable people in this regard will hopefully answer you), but my Golden also was a "nipper" when a puppy. He would bite when playing (or wanting to play) no matter what I did to stop him. He also chewed paper, magazines, toilet paper, newspapers, etc if within reach (yes, we did learn...). Once he finished teething, he stopped chewing the paper and stopped chewing on me.

Good luck...

Jake's mom