The effects of emotions on online political participation: a systematic review

Emotions are central to political behavior; however, no comprehensive synthesis has examined how they shape online political participation (OPP) across platforms and political contexts. This paper conducts a systematic review, screening 4,562 records and synthesizing 76 studies reporting 139 associations between emotional variables and OPP. The review is registered with OSF (https://osf.io/j4csp/overview?view_only=a7f6b620edf5434e8df1f983e37264a2). We included empirical studies in English that reported an association between at least one emotion measure and one OPP measure, excluding theoretical work, reviews, and studies focused on offline or traditional media. Studies were narratively synthesized using thematically organized vote counting by direction of effect. The results show that emotions exert a predominantly mobilizing effect on OPP, with a clear hierarchy: hope (100% mobilizing), enthusiasm (87.5%), and negative emotions (85.3%) emerge as the most consistent mobilizers, whereas fear, positive emotions, and anger show robust effects with platform-specific sensitivities. Anxiety and sadness present mixed patterns, with anxiety uniquely reversing direction—mobilizing in democracies but demobilizing under authoritarianism. However, only 6.5% of associations derive from experimental designs, revealing a substantial causal deficit. The review also highlights geographical and methodological gaps, particularly the concentration in WEIRD contexts and dominant platforms. Substantively, the results demonstrate that emotional effects on OPP are robust but contextually contingent, challenging universalist models. By systematically synthesizing the extant research, this paper provides an empirical foundation to advance theories incorporating contextual moderators of emotional mobilization.