After twenty years as The New Yorker's senior drama critic, John Lahr is stepping down (although he will still write Profiles for the magazine). Here Lahr talks with his editor Deborah Treisman about growing up in the showbiz world of his father, Bert Lahr; the role of theatre (and critics) in our culture; and the playwrights that have been important to him. Also: 2012 book recommendations from Louis Menand, Judith Thurman, and Marisa Silver.