Personal and Collective Memories and Future Thoughts: A Laboratory Study of Episodic and Non-Episodic Detail

Self-based mental time travel - the ability to remember past events and imagine future events on a personal timeline - is well-characterized in cognitive science. A similar, but less-understood, ability is that of collective memory and collective future thinking, termed collective mental time travel (CMTT). To our knowledge, this is the first study to investigate the episodic richness of collective memory and future thoughts using an in-person laboratory paradigm. In two studies (UK and Turkey), we examined the effect of Event Type (collective, personal; between-groups) and Temporal Orientation (past, future; within-groups) on quantities of episodic and non-episodic details. Results show that personal events contained more episodic detail compared to collective events, and past events were associated with more episodic detail than future events. The distinction between personal and collective events was more pronounced in the UK than in Turkish sample, hinting at an influence of cross-cultural context on the episodicity of collective memories and future thoughts. Additionally, we observed a relationship between the episodicity of the past and the future exclusively in the UK population and for personal events, partially supporting the constructive episodic simulation hypothesis. These findings initiate a deeper understanding of the underlying cognitive processes that enable humans to engage in collective mental time travel.