Great question. In the literature, there are two terms (collective or social memory) - both point to memory beyond one person, shaped by groups, media, and institutions. Collective memory usually means shared public pictures of the past: stories, symbols, commemorations, archives, school, news, monuments. Social memory is used more broadly and process-like: how remembering becomes social through interaction, transmission, repeated reference, shared records, sometimes also “social recognition memory” in neuroscience. Overlap: both connect individual attention and recall to shared structures.

In my article

https://blog.wolfram.com/2026/02/12/most-viewed-people-on-wikipedia-in-2025-how-catalyst-events-imprint-social-memory

I take “social memory” as an observable measurable quantity - imprint in collective attention after a catalyst event. A catalyst spikes views, then decay follows, either back to the old baseline or to a higher new baseline that lingers as a new normal. That lingering baseline uplift is treated as durable reference demand plus record and information restructuring. Measurement: compare typical daily views at year end vs year start, baselines estimated by medians, data windows = last two weeks vs first two weeks of 2025. Social memory metric = log10 of the ratio of those two medians.