Public opinion polls are a central feature of contemporary electoral campaigns, but their effects on individual voting behavior remain theoretically and empirically contested. Polls may operate as informational and social cues, signaling party viability, electoral momentum, and perceived majority support. Existing research points especially to bandwagon effects, strategic voting, and potential mobilization or demobilization, while underdog effects have received less consistent support. However, less is known about which voters are most susceptible to polling information and how psychological and political dispositions shape these responses, particularly in Portugal, where research has focused mainly on aggregate election results and polling accuracy.

This work examines how exposure to pre-election polling information affects electoral attitudes and decision-making in legislative elections. Drawing on bounded rationality, heuristic processing, and social influence perspectives, the study analyses whether poll exposure shifts vote intention, party evaluations, and willingness to vote, and whether these effects are moderated by political efficacy, Big Five personality traits, and populist attitudes.

The project uses a survey-experimental design simulating realistic electoral scenarios in which participants are exposed to polling information indicating changes in party support or electoral viability. The analytical strategy distinguishes between the decision to vote and the decision of whom to vote for, allowing poll effects on participation, strategic choice, and preference change to be examined separately. By integrating political psychology with experimental evidence on polling effects, this study contributes to understanding how citizens process electoral information under uncertainty and why the same polling cue may mobilize, demobilize, or redirect different voters. The project also informs broader debates about campaign communication, media responsibility, and the regulation of polling information in contemporary democracies.