Collaboration changes both the content and the structure of memory: Building the architecture of shared representations.

Memory research has primarily focused on how individuals form and maintain memories across time. However, less is known about how groups of people working together can create and maintain shared memories of the past. Recent studies have focused on understanding the processes behind the formation of such shared memories, but none has investigated the structure of shared memory. This study investigated the circumstances under which collaboration would influence the likelihood that participants come to share both a similar content and a similar organization of the past by aligning their individual representations into a shared rendering. We tested how the frequency and the timing of collaboration affect participants' retrieval organization, and how this in turn influences the formation of shared memory and its persistence over time. Across numerous foundational and novel analyses, we observed that as the size of the collaborative inhibition effect-a counterintuitive finding that collaboration reduces group recall-increased, so did the amount of shared memory and the shared organization of memories. These findings reveal the interconnected relationship between collaborative inhibition, retrieval disruption, shared memory, and shared organization. Together, these relationships have intriguing implications for research across a wide variety of domains, including the formation of collective memory, beliefs and attitudes, parent-child narratives and the development of autobiographical memory, and the emergence of shared representations in educational settings.