Two-Sided Messages Promote Openness for Morally Based Attitudes.

This research demonstrates that two- versus one-sided counterattitudinal messages can encourage people with a strong moral basis for their attitudes to be more open to contrary positions. Studies 1A/B demonstrated that the interaction between moral basis and message sidedness was present not just for a controversial issue with balanced views in society but also for a topic with a majority opinion. In Study 2, the relative effectiveness of two- over one-sided messages for people with a moral attitude basis was shown to occur only when the two-sided message respectfully acknowledged the recipient's side. In Study 3, the effect was replicated in a preregistered experiment. Furthermore, moral bases provided unique predictive power beyond alternative attitude strength indicators. Across all studies, perceived appreciation of the speaker acknowledging the recipient's view mediated the impact of the independent variables on openness.