Differentiation drives the erosion of positivity on social media
A new study published in PNAS finds that as social media users become more differentiated in their interests and social circles over time, their posting becomes less positive. Analyzing millions of posts, researchers observed a gradual erosion of positive sentiment driven by social differentiation processes, challenging the notion that negativity spreads simply through contagion.
Background
- The paper (PNAS, 2025) argues that online polarization isn't mainly caused by algorithms or echo chambers, but by a natural "differentiation" process: as social media groups grow, users compete for attention by adopting ever more extreme or negative stances to stand out, gradually eroding the positivity that initially held the community together.
- "PNAS" (Proceedings of the National Academy of Sciences) is a highly prestigious peer-reviewed journal. The findings challenge the common narrative that platforms like Facebook or Twitter/X are solely responsible for driving negativity.
- The study uses agent-based modeling (a type of computer simulation) to test how individual incentives for attention create this erosion at the group level, suggesting that even well-intentioned design changes may not reverse the effect if the underlying social dynamics remain.