Does mere exposure to ideas encourage belief in them?

Numerous psychological findings have shown that mere exposure to ideas makes those ideas seem more true, a finding commonly referred to as the “illusory truth” effect (e.g. Hasher et al., 1977). In the presence of pervasive misinformation, this basic feature of cognition may undermine the functioning of a democratic society (Pennycook et al., 2018). However, genuine beliefs do not only produce judgments of truth, they also imply other beliefs and drive decision-making. Here, we sought to examine whether mere exposure to statements produces genuine beliefs by examining whether people draw inferences from statements after mere exposure. Surprisingly, and in contrast to familiarity-based accounts of the illusory truth effect (e.g. Dechêne et al., 2010), we found that exposure to “premise” statements affected participants' truth ratings for novel “implied” statements. This “illusory implication” effect suggests that exposure to false statements has further-reaching impacts than previously thought and calls for a new mechanistic account of these effects.