Social scientists who study groups disagree about whether (and to what extent) dyads ought to be included in their work. In this article, I argue that dyads are not really groups because (a) dyads are more ephemeral than groups, forming and dissolving more quickly; (b) people feel stronger (and often different) emotions in dyads than in groups; (c) dyads are simpler than groups—some group phenomena cannot occur in dyads, and those that do may operate differently there; and (d) research on dyads is carried out almost independently (by different people, applying different theories and methods, and publishing their work in different outlets) from research on groups. I also review some of the conceptual and methodological problems that can arise when dyads are mistakenly viewed as groups.
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