covid-19 exacerbated the worldwide shortage of nurses. the registered nurses association of ontario reported that the number of vacancies among registered nurses in the province has more than quadrupled since the beginning of 2016 and has more than doubled since the start of the pandemic. reasons identified by researchers contributing to nurses leaving the profession have included lack of support from peers and management, little input from nurses into their practices, increasingly heavy patient loads, and increasing patient acuity. the purpose of this constructivist grounded theory study was to develop a theory to explain the process of social norm formation of nurses working in groups and to identify the factors limiting or facilitating their development. group social norms, or rules, contribute to the environment in which nurses practice. [...]