Mr. Kirby has attained financial success and a position of social and economic power. The play, however, asks its viewers to evaluate whether Americans should aspire to be like Mr. Kirby. His achievement is contrasted with Grandpa Vanderhof's version of the American Dream, earning just enough money so that one can survive and do exactly what one wishes. Mr. Kirby may initially think Grandpa's ideas are "un-American," but the Vanderhof's infectious happiness and love for one another encourages the audience to revise their definition of the American Dream to include attainment of both material success and personal fulfillment.

Success and Failure Throughout the play, the Vanderhof-Sycamore way of life calls into question conventional definitions of success and failure. Although Essie and Penny might be called "failures" because they lack talent in dancing and painting/playwriting respectively, the play depicts them as successful because each clearly finds joy in what she does. Tony Kirby initially thinks that in order to be "successful," he must forget about the dreams he had in college and accept his position as a Vice President at Kirby & Co. But his contact with Alice's family convinces him that it is a mistake to give up one's dreams, as his father did when he was a young man. In the world of the play, failure to follow one's dreams and desires is the only genuine failure. The audience is encouraged to re-define "success" in terms of happiness rather than in terms of just money and status.

Individualism The positive portrayal of eccentric and singular behavior in You Can't Take It with You also reflects the American belief in individualism. Many works in American literature celebrate individuals who rebel against the restraining conventions of society at large. All the Vanderhof-Sycamores could be classified as "rugged individualists" who follow the dictates of their own hearts and disregard those in the majority who disapprove.

Difference The Vanderhof-Sycamores not only stand apart as "different" from the conventional world around them, but they also are willing to accept others who are different. Their openness is reflected—through humorous exaggeration—in the way that they allow anyone to move into their house or sit down at their dinner table. And although the play's ethnic characters are depicted in a stereotypical manner which might offend late-twentieth-century sensibilities, the acceptance of African-American and Russian characters as part of the family was seen as quite liberal and open to the value systems of most 1930s audiences. The play's happy ending also reveals that differences may only be superficial, since Mr. Kirby, who once had dreams of being a trapeze-artist, may be more like Grandpa than anyone suspected.

Culture Clash Much of the humor in You Can't Take It with You derives from the clash between the lifestyles of the two families. The Kirbys might be seen to reflect mainstream upper-middle-class American culture, while the Vanderhof-Sycamores resist the conventions of that same culture, making up their own rules. While themes of culture clash can often be used to show how divergent groups can come to understand each other, this is a secondary concern in Kaufman and Hart's play. The primary purpose of introducing a straight-laced family such as the Kirbys into the wacky world of the Vanderhof-Sycamores is to watch the sparks fly. The first act clearly establishes the goofy nature of the family and raises audience expectation as interaction with citizens of the "real world" approaches. Laughs are generated from both the eccentric behavior of Grandpa Vanderhof and his family and the shocked reactions the Kirbys have to this oddball group.