These two full grown Males are Pals. They love to play with people as well as with each other. Because we socialized them early and often they are both good with people while they're on their leashes. I often allow children to pet them during a walk. We raised them with lots of love and have NEVER taught them to be aggressive. However, when they are in their own yard or house they are wary of folks passing by. At the same time they've never showed aggression towards guests we've had over. As a matter of fact we sometime have to tell them to go lay down and stop pestering our guests to play with them. Again, they are loveable and loyal family dogs. These dogs do not have to be taught aggression to be protective. In a nut shell, they seem to know when to be nice and when to not be so nice. They really can sense what you want from them. Again, I highly recommend socializing your German Shepherd often and early in the training phase. You can have a wonderful and friendly dog who is not a whimp without worrying if the dog is going to bite your friends or even your family.