Research on group decision‐making in speech communication has assumed interaction processes are important determinants of group decisions. However, major psychological theories of group decision‐making challenge this assumption. This study tested a prominent social psychological theory, Davis's Social Decision Scheme Model, against an interaction‐based model of group decision‐making, the Valence Distribution Model recently developed by McPhee, Poole, and Seibold. The theoretical rationale for the comparison was provided by the theory of structuration, which predicted the Valence Distribution Model would mediate the effect of Social Decision Schemes on group decisions. Results substantially supported this prediction.