Similarly to how Kassowitz portrayed the youngsters in Paris' banlieues, the Dardenne brothers further the analisys and depiction of the petty tricks and misfortunes of those that society casted away. The main character is reluctant to living a normal life, even when chances are presented to him and when responsability should call him to order: he cannot see himself fit in such society. The directors tell it well.
L’enfant follows a young couple with a newborn child. When the opportunity appears to make money through selling of the child, Renier takes it and chaos ensues. The Dardenne brothers manage to snatch my wig consistently with their emotional terrorism and flawless portrayal of human behavior.
The extreme naturalism is meant to pare down the story to the bare essentials, to let reality speak for itself. This academic pretension--the brothers and cinematographers confess that realism this uncompromising is hard to craft--doesn't reach the heights it shoots for. The ending is weak, the acting is sometimes contrived, as when they flirt with each other at the start, it was observant but emotionally sterile.
Such a a simple plot, but such a strong development of characters, this development can be possible due to the great performance of the actors, (especially Jérémie Renier). The film begins and ends with an opposite idea: at the beginning Dardenne brothers show to the viewers two kids taking care of another kid, at the end Dardenne brothers show to us two adults taking responsibility in their lifes. Morality.