Search NAPiD.

As political discourse has migrated onto commercial social media platforms, private companies have assumed an increasingly consequential role in regulating political speech—deciding what stays online, what is removed, and what is demoted or labeled. This review synthesizes recent scholarship on platform content moderation as a form of political governance, examining three interrelated dimensions: the legal and institutional status of platforms as "new governors" of speech; the comparative politics of state efforts to regulate platform moderation; and the uneven, often Western-centric application of moderation systems across national and linguistic contexts. Drawing on legal scholarship, comparative political science, and empirical platform studies, the review finds that content moderation increasingly functions as a hybrid public-private governance regime, shaped simultaneously by platform policy, national regulation, and transnational pressure, with outcomes that vary substantially by country, platform, and political system. The review highlights a persistent asymmetry: moderation systems designed primarily around U.S. legal norms and English-language content are applied, often poorly, to political speech in linguistically and politically diverse contexts, particularly across the Global South. The review concludes by outlining implications for platform accountability, comparative regulatory design, and future research on moderation equity.

Political polarization in democratic societies has intensified over the past two decades, coinciding with the rise of social media as a dominant channel for political information and expression. This narrative review synthesizes evidence from systematic reviews, meta-analyses, and empirical studies published between 2010 and 2025 to evaluate the role of social media in shaping political polarization. Drawing on prior systematic work, the review addresses four themes: selective exposure and media effects, the contested empirical status of echo chambers and filter bubbles, the role of algorithmic curation and recommender systems, and the distinction between affective and issue-based polarization. The synthesis indicates that while pro-attitudinal media use is consistently associated with heightened polarization, direct causal evidence that social media use produces echo chambers is weaker and more contested than popular discourse suggests. Existing research is disproportionately concentrated on Twitter/X and United States samples, constraining generalizability. The review concludes by identifying priority areas for future research, including cross-platform and cross-national designs, longitudinal causal identification strategies, and interventions capable of reducing affective polarization without suppressing legitimate political expression.

In the 21st century, the proximal examination of fish behavior—the analysis of immediate genetic, physiological, neurobiological, and environmental mechanisms triggering behavior—has shifted from basic observation to a high-tech, predictive science. Driven by rapid technological innovation and global environmental pressures, modern researchers use fish behavior as a neural proxy to reveal complex internal states, breaking old assumptions that fish operate on simple, rigid reflexes.