Repetition increases perceived truth of interpersonal statements from both politically congruent and incongruent sources

People judge repeated information as truer than new information. In politics, this truth effect may be used to manipulate beliefs and evaluations of other politicians (e.g., by repeatedly derogating an opponent). We investigate the truth effect for such statements about others in political contexts. In two pre-registered experiments, we examined how repetition and source-recipient political congruency influence believability of statements about unknown individuals and the evaluation of these individuals. In Experiment 1 (N=234), using negative statements, and Experiment 2 (N=235), using both negative and positive statements, the truth effect emerged consistently: repeated statements were rated as truer than new ones. Notably, this effect was not significantly influenced by the political congruency between statement source (manipulated political affiliation) and recipient (measured political affiliation). Turning to evaluations, a higher number of repetitions strengthened positive evaluations for targets described by positive traits, and increased to a lesser extent negative evaluations for targets described negatively. Our findings indicate that, under the conditions examined here, repetition increases believability of interpersonal statements to the same extent across political divides.