The Wild Child (1970)

At last an adult film to which you can take your children.

In 1798, a feral boy is discovered outside the town of Aveyron, France. Diagnosed as mentally impaired, he is relegated to an asylum. A young doctor named Jean Itard becomes convinced that the boy has normal mental capacity, but that his development was hindered by lack of contact with society. He brings the boy home and begins an arduous attempt at education over several years.