The daughter of the household is behaving strangely. Her parents clamp down on her, which causes the rebellion to pop out in a different way, like a game of whack-a-mole.
Believe it or not, adolescence as a distinct phase of life wasn't even noticed until about a hundred years ago. In primitive society there are certain markers, like menarche in women, but everyone needs to contribute, and so growth is a gradual accretion of responsibilities. But childhood as a distinct time of life, and adolescence are fairly advanced concepts. And because even the most obvious ideas are accepted only gradually, a movie like this was a definite necessity for many even as the second half of the 20th century began.