The critical response to This Is Our Youth has been overwhelmingly positive. Many critics, like Robert Brustein, in his review for the New Republic, have applauded the play's realism and praised Lonergan as a “penetrating cultural historian.” Brustein characterizes the play as a “sharp [x-ray] of social abscess and moral atrophy,” noting its “tough-minded, almost clinical examination of the aimlessness, the vacuity, and the emotional deadness” of its privileged main characters. He concludes, “Lonergan's capacity to evoke these qualities without moralizing about them is the mark of a significant writer.”

Stefan Kanfer, in a review for the New Leader, echoes Brustein's assessment of Lonergan's talent when he writes, “A lesser playwright might have been content to let [the initial conflict] occupy the evening.” But while Dennis and Warren are trying to decide what to do about the money, “Lonergan introduces a third party and takes the...