Truth Bias and Partisan Bias in Political Deception Detection

This study tests the effects of political partisanship on voters’ perception and detection of deception. Based on social identity theory, in-group members should consider their politician’s message truthful while the opposing out-group would consider the message deceptive. Truth-default theory predicts that a salient in-group would be susceptible to deception from their in-group politician. In an experiment, partisan voters in the United States (N = 618) watched a news interview in which a politician was labeled Democratic or Republican. The politician either answered all the questions or deceptively evaded a question. Results indicated that the truth bias largely prevailed. Voters were more likely to be accurate in their detection when the politician answered and did not dodge. Truth-default theory appears robust in a political setting, as truth bias holds (as opposed to deception bias). Accuracy in detection also depends on group affiliation. In-groups are accurate when their politician answers, and inaccurate when he dodges. Out-groups are more accurate than in-groups when a politician dodges, but still exhibit truth bias