Individual differences in experiential diversity shape event segmentation granularity.

Parsing experience into meaningful events or units, known as event segmentation, may be critical for structuring episodic memory, planning, and navigating spatial and social environments. However, little is known about what factors shape inter-individual differences in event segmentation. Here, we show that individuals with greater variation in their daily social and spatial lives (experiential diversity) displayed more fine-grained event segmentation during a movie-viewing task. This relationship held after considering potential confounds, such as anxiety, loneliness, and socioeconomic factors, and was primarily driven by variation in social experiential diversity. Exploratory analyses revealed that the relationship between social experiential diversity and segmentation granularity was stronger in high-anxiety participants, suggesting heightened vigilance to fine-grained social-emotional cues during movie-viewing. These results support the view that event segmentation can occur proactively based on social and spatial environmental dynamics learned "in the wild" and provide a potential cognitive pathway through which isolation impacts cognitive health.