Humor is political. From stinging ridicule that reveals more about the mockers than about the targets of their taunts to childlike silliness and drollery, all forms of humor showcase our common humanity. Yet shared laughter is also contradictory: It can divide as well as unite. This contradiction is a key point of departure in the work of the international art collective Slavs and Tatars, and it guided their curation of the Thirty-Third Ljubljana Biennial of Graphic Arts, “Crack Up-Crack Down.”

The art on view at the biennial’s nine venues offered plenty of evidence that the best satire—whether