One of the main lines of reasoning in the contemporary debate on media effects is the notion that selective exposure to congruent information can lead to political polarization. Most studies are correlational, potentially plagued with self-report biases, and cannot demonstrate time order. Even less is known about the mechanisms behind such an effect. We conducted an online quasi-experiment with a sample matching the characteristics of the Dutch population closely (N = 501). We investigate how selective exposure can lead to polarized attitudes and which role frames, facts, and public opinion cues play. While we find that facts learned can help explaining attitude change and that selectivity can influence the perception of public opinion, we cannot confirm that people generally polarize.