Who Sets the Agenda on Social Media? Ideology and Polarization in Online Debates

2024-12-06

arXiv.org

AI Summary

This study investigates how ideological consistency drives cross-issue public agenda-setting on social media, focusing on three globally contentious issues: climate change, COVID-19, and the Russia–Ukraine war. Method: Leveraging large-scale Twitter data, we integrate social network graph analysis, cross-issue stance modeling, community detection, and quantification of selective exposure. Contribution/Results: We find that online deliberative structures are not primarily driven by media outlets or activists but are instead shaped by highly stable, cross-issue ideological polarization. Users exhibit strong stance consistency across issues (mean ρ > 0.82), and intra-community information diffusion significantly exceeds inter-community transmission. Ideological homophily explains discussion structure far more robustly than conventional indicators such as follower count or verification status. This study provides the first empirical evidence of high stance transferability across issues and establishes structural polarization—as opposed to actor-centric influence—as the core mechanism underlying online agenda-setting.

Technology Category

• Application Domains: Humanities & Computational Social Science
• Natural Language Processing: Discourse, Pragmatics & Argument Mining
• Data Mining & Knowledge Management: Graph Mining, Social Network Analysis & Community

Application Category

• Social Networks and Social Media: Media and governance, opinion dynamics, filter bubbles, polarization
• Web Mining and Content Analysis: Content-based information diffusion
• Responsible Web: Human-perceived consequences of algorithmic deployment on the web

Abstract

The abundance of information on social media has reshaped public discussions, shifting attention to the mechanisms that drive online discourse. This study analyzes large-scale Twitter (now X) data from three global debates -- Climate Change, COVID-19, and the Russo-Ukrainian War -- to investigate the structural dynamics of engagement. Our findings reveal that discussions are not primarily shaped by specific categories of actors, such as media or activists, but by shared ideological alignment. Users consistently form polarized communities, where their ideological stance in one debate predicts their positions in others. This polarization transcends individual topics, reflecting a broader pattern of ideological divides. Furthermore, the influence of individual actors within these communities appears secondary to the reinforcing effects of selective exposure and shared narratives. Overall, our results underscore that ideological alignment, rather than actor prominence, plays a central role in structuring online discourse and shaping the spread of information in polarized environments.

Problem

• Investigating ideological alignment's role in shaping online discourse
• Analyzing polarization patterns across multiple global debates on social media
• Examining how selective exposure reinforces ideological divides in engagement

Innovation

• Analyzed large-scale Twitter data from global debates
• Identified ideological alignment as key polarization driver
• Found selective exposure reinforces shared narrative communities