Who is Joan Webber from Sexual Perversity in Chicago and the Duck Variations: Two Plays and what is their importance?

Joan Webber is a bitter and hostile woman. Joan puts herself out there and then shoots down everything that comes her way. Joan is critical of Deborah and downright hostile to everyone else, even Shapiro. It is unclear why Joan is so bitter. The reader is left to believe that Joan is buried deeply in emotional distress and uses ridicule and insult as a defense mechanism. This can be seen clearly in the midst of Joan's existential crisis.