Cognitive approaches to patient safety have mostly focused on individual decisions. This study instead examines group decision-making and its safety implications. The authors describe four pitfalls associated with group decisions: groupthink in which the strongly connected mentality of members hinders dissenting opinion; social loafing in which people expend less effort because of a perceived failure to obtain individual credit for efforts; group polarization in which individual moderate positions are subsumed by more extreme or effort intensive group decisions; and escalation of commitment in which a poor outcome following a significant investment results in further commitment of resources instead of exploring a new approach. These four concepts can serve as a theoretical framework for future empiric work to characterize and improve group decision-making as an aspect of safety culture.