Truth Bias and Partisan Bias in Political Deception Detection

Abstract

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.