The movie wrestles with some big and universal themes. The kids begin to behave badly, mainly in response to their father's all-encompassing anger and frustration. But when one grows up, he begins to realize that all things are connected, specifically families and nature. In a kind of dream/fantasy sequence, he learns empathy and tolerance for his family. In general, all of these themes -- and others -- are not literally outlined. They're up for interpretation and debate.
Certainly the father is no role model. He's bitter and miserable and takes out his frustrations on his family. He keeps preaching that, to get ahead in the world, you have to be ruthless. His oldest son, Jack, struggles with these teachings his whole life, but in the end -- in a kind of dream/fantasy sequence -- he seems to reconnect with his family and find a kind of inner peace, though this revelation is very abstract.
Most of the violence is just under the surface. The father is constantly angry and threatening, but he rarely lashes out in a physical way -- though in one scene, he tries to slap one of his boys for talking back at the dinner table. A boy drowns in a swimming pool. A little blood is on display during a poetic flashback sequence. Two boys play with a BB gun, and one is shot in the finger. Other scenes include some mildly disturbing imagery.
There's something akin to a "creation of life" montage with some peripherally sexual images; viewers see a pregnant woman, and later they see her with her newborn baby.
"Hell," "my God," and one character says "get 'em by the nuts."
Drinking, Drugs & Smoking
In brief sequences, there are hints of secondary characters smoking, though none of the main characters or kids actually smokes.