It has long been customary to deal with the social theatre of the 1930's in terms of explicit content; I shall deal with it in terms of theatrical style.
The first point that needs to be made is that realism was not a discovery of the social theatre of the 1930's. Both as an ideal and as a practice, realism was strongly in evidence in the 1920's, if not indeed in the successful Belascoism of earlier decades. The producer-director Arthur Hopkins, whose Shakespearian productions in association with his distinguished designer Robert Edmond Jones were notably symbolistic, had perhaps his greatest success with his naturalistic production of What Price Glory? in 1924. The nascent Theatre Guild, which was about to collapse after its initial production in 1919 of Benavente's symbolist commedia dell'arte, The Bonds of Interest, was launched upon a successful career with its next, ultra-realistic, production of St. John Ervine's John Ferguson.