Online Toxicity: Birthed from Polarization, Raised by Platforms

Online toxicity has become a defining feature of contemporary digital discourse, permeating all forms of online discussion, from news websites and discussion forums to social media platforms. While prior research has examined toxic behaviour across these domains, less attention has been paid to the interplay among broader socio-political polarization, platform architectures, and psychological mechanisms that jointly sustain this discursive paradigm. This literature review proposes a multi-level integrative framework to conceptualize the toxicity lifecycle. At the macro level, affective polarization fosters societal antagonism, reinforcing entrenched in-group and out-group dynamics. However, the intensity and expression of these societal cleavages are shaped by distinct media–political system configurations, including varying degrees of political parallelism, and journalistic professionalization. At the meso level, platform affordances such as algorithmic amplification and engagement-based metrics promote emotionally charged, conflict-driven content. At the micro level, disinhibition lowers normative constraints on expression, often leading to verbal aggression that undermines the principles of healthy public deliberation. Addressing these challenges requires a comprehensive response that brings together users, platforms, and policymakers to safeguard the normative democratic values of constructive public deliberation.