It's been ages since I lived with a dog, but our neighbor's GSDs crack me up. They have such different personalities. Her male, Seneca, was the runt of the litter and has always had a very quiet, somewhat shy and gentle personality. He's actually afraid of my big hubby, but adores our son. He pretty much only barks little yips at the door when he wants to go back in.

Her new dog, Ruby, is a small female...who doesn't really look like a GSD (She is the offspring of Seneca's brother). She is reddish colored and almost looks like a hyena. She is a sassy one, too. ALWAYS barks, every time she's outside and sees someone. We tease her and call her silly girl, since she really has no reason to bark at us. Sometimes she even gets her hackles up, even though I suspect she's not really aggressive, just likes to put on an act. I think she sorta wears the pants, though. Sometimes she will bark at us and Seneca will follow suit, mostly due to peer pressure, it seems. He never barked at us before Ruby came along. He looks sheepish when he does it.

Even though these dogs are the same breed and are from common bloodlines, they are very different creatures.