At the park one day I was approached by a woman who asked if her puppy could play with Luke. "Sure;" although I did tell her that Luke loves the fact that he can intimidate puppies. "Wonderful" she said; I need an adult dog to put him in his place; and I have to agree, she did. This particular puppy was lacking in the manners department and without any guidance he was sure to become worse. Puppies need a great deal of teaching; it starts as soon as they are born. Their Mother teaches and guides them through their weeks with her. I've often seen Mom's flatten a puppy or two and hold them down until they scream. Is she being cruel? Not in anyway, she is doing you the new puppy owner a favor.
Many people consider disciplining a new puppy to be mean or cruel. "They're only a puppy" is the common response to someone attempting to discipline. Puppies need discipline; they need it from their human family and other dogs; mature friendly dogs. The first lesson is usually nipping; if you are lucky enough to have an adult dog as well then you are going to be much better off. Adult dogs let puppies know very quickly what is acceptable biting and what is not. It's all about feedback.
Pretty much the whole concept of how dogs learn is based on association and feedback. If a puppy does naughty things like chewing shoes or your feet and receives no feedback; then they never learn what is and is not acceptable. Yesterday at the park a young dog came charging straight at Luke; she never stopped, she barreled right into him sending him flying on his butt. At 10 years old he should not be taking a hit like that; but he never saw it coming, neither did I. I assumed she was going to stop. As soon as contact was made Luke sounded like a grizzly bear; the young female knew immediately that she'd made a mistake. Luke had some blustering to do and it was over; she left and steered clear of him the rest of the time.
Had Luke not responded to her actions; she would have thought nothing of it and probably done it again. Disciplining starts out small and grows with a lack of compliance. All dogs are different; some puppies are very sensitive to feedback, others need more bluster in their feedback. Just like with Luke's feedback; there was no touching involved it was all noise and commotion. But it left had impact; he got his message across and she learned. This is the perfect scenario.
Guidance for both good and bad in the form of feedback is essential. That added with reward for good behaviors helps push a new puppy in the right direction. But to sit back and do nothing; to let a puppy get away with inappropriate behaviors is setting yourself up for a whole heap of trouble down the road. Puppies are little clean slate; just waiting to be filled with great information, that's your job as their new guardian.