yeah I was told the great pyrenees only lives about 8 years. I never known anyone that had one so I'm not 100 percent sure. But I know that big dogs have a shorter lifespan than medium and smaller size dogs.
I breed GP and the average age is 12-14yrs. It all depends alot on how they are brought up. I have a 9 year old male that acts like a puppy and still runs up and down our land with the 2 year old pyr. I think he will be around for a while (I hope).
jgermansh, I'm sorry about your sister's experience. You are correct in saying they need proper socialization. EVERY dog does.
ANY dog who spends his/her life on a chain with little or no human contact is likely to become human aggressive.
In the case of the Pyr, you are dealing with a very large dog who is gentle and loving by nature and when bred & raised properly, great temperments.
My Pyrs have been around my grandchildren from puppyhood, including newborns. They are gentle beyond belief and with the exception of small kids getting knocked onto their butts now and then in play, I don't have to worry about the dogs.