Savage Girls and Wild Boys by Michael Newton.
Non-fiction-various stories of children through the ages who have either lived for a significant period of time among animals, or because their parents were psychotic, never learned language skills and human interaction.
Apparently it happens more often than you would think-one story is of a Russian boy in the 90's, another of an American girl whose father kept her locked in a room, tied to a chair, in the 70's.
Kind of makes you wonder what the flying hell gets into peoples minds to make them think it's ok to just discard children or keep them tied to a chair for 13 years.
The girl from the 70's-they called her Genie-was truly a heartbreaking story. Once she was rescued, she was kept for observation, bounced from one home to another. I guess now she lives in some assisted living facility in California. Poor baby girl.
Read it, though it will break your heart.