Two quantitative meta-analyses examined how the presence of visual channels, vocal channels, and synchronicity influences the quality of outcomes in negotiations and group decision making. A qualitative review of the literature found that the effects of communication channels vary widely and that existing theories do not sufficiently account for these contradictory findings. To parsimoniously encompass the full range of existing data, the authors created the communication orientation model, which proposes that the impact of communication channels is shaped by communicators' orientations to cooperate or not. Two meta-analyses — conducted separately for negotiations and decision making — provide strong support for this model. Overall, the presence of communication channels (a) increased the achievement of high-quality outcomes for communicators with a neutral orientation, (b) did not affect the outcomes for communicators with a cooperative orientation, but (c) hurt communicators' outcomes with a noncooperative orientation. Tests of cross-cultural differences in each meta-analysis further supported the model: for those with a neutral orientation, the beneficial effects of communication channels were weaker within East Asian cultures (i.e., Interdependent and therefore more predisposed towards cooperation) than within Western cultures (i.e., Independent).