Repeated statements are perceived as more valid than novel ones, termed the illusion of truth effect, presumably because repetition imbues the statement with familiarity. In 3 studies, the authors examined the conditions under which and the processes by which familiarity signals from repetition and argument quality signals from processing of message content influenced agreement with persuasive arguments. Participants with low or high motivation to process information were presented persuasive arguments seen once or twice. In all 3 studies, repetition increased the persuasiveness of weak and strong arguments when little processing of message content occurred. Two of the studies used a process dissociation procedure to reveal that both greater controlled processing (which reflected argument content) and the greater automatic influence of familiarity (which reflected repetition) were associated with increased acceptance of strong arguments but that greater controlled processing dissipated the benefits of familiarity for agreement with weak arguments.(PsycINFO Database Record (c) 2016 APA, all rights reserved)