What are the motifs in Fool for Love by Sam Shepard?

Family is a theme in this story. The fact that Eddie, May, and the Old Man are immediate family adds an unusual, volatile twist to the situation in the play. Over the course of the drama, Shepard drops hints that May and Eddie are related. It is not until the end that Shepard reveals that they are half-siblings and the Old Man is their father. In light of this revelation, Eddie and May's relationship is all the more disturbing. Yet while this is not a normal family, there are the same kind of misunderstandings and personal dynamics that exist in normal family relationships.