This article demonstrates experimentally that in the context of dyadic conflict, patterns of interpersonal communication (PIC), supported by a particular Group Decision Support System (GDSS) technology, affect the quality of decision making. A GDSS technology that supports confrontation of strongly-internalized personal meanings appears less efficient in supporting the resolution of ethical dilemmas than in stimulating interdependent co-construction of shared-meanings between opposing parties. Intersubjectivity and reciprocity are adapted when the conflict is linked to variables of personality and cultural identity. GDSSs are an efficient tool to support intergroup communication and relations. This article discusses the direct implications of our research for the study of intercultural negotiation and conflict resolution.