Although it is widely assumed that cohesiveness promotes positive outcomes in group psychotherapy, the empirical evidence for this notion is very limited. In light of persistent confusion over how it should be conceptualized and measured, we argue that the term “cohesiveness” is too amorphous to serve as an adequate organizing principle for theory and research, and that it should be replaced with more cogent and specific alternatives. Drawing on social psychological literature, we also question the intuitive notion that cohesiveness necessarily leads to positive outcomes. To the extent that the need for harmony is prioritized over the need for personal expression, dissent, and challenge, then it could be that cohesiveness might have negative as well as positive implications for members of group therapy.