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Topic

The Photo-Truthiness Effect: The Influence of Nonprobative Photos on Truth Judgments in a 2 Phase Procedure

Department of Psychology

Date & location

• Friday, April 11, 2025
• 3:30 P.M.
• Cornett Building, Room A228

Examining Committee

Supervisory Committee

• Dr. Steve Lindsay, Department of Psychology, University of Victoria (Supervisor)
• Dr. Jim Tanaka, Department of Psychology, UVic (Member)

External Examiner

• Dr. Daniel Bernstein, Department of Psychology, Kwantlen Polytechnic University

Chair of Oral Examination

• Dr. Dan Russek, School of Languages, Linguistics and Cultures, UVic

Abstract

Truthiness is the belief or assertion that a statement is true based on intuition and subjective perception rather than evidence or critical examination. Recent research has demonstrated that the presence of a nonprobative photo - an image that is related to a claim but provides no direct evidence for it - can increase the probability that a person will judge the claim as true. This photo-truthiness effect is hypothesized to occur because such images enhance processing fluency, making the claim easier to process and bringing related concepts to mind. This increased fluency is then misattributed to familiarity and truth, leading to greater truth ratings. In most photo truthiness studies, participants evaluate claims in a 1-phase procedure, whereby they see a claim with or without an accompanying photo and immediately judge its veracity. This design facilitates processing of both the claim and the photo simultaneously, potentially leading some to discount the photo’s influence. The present research introduces a 2-phase procedure, in which participants first view trivia claims with or without an associated photo and only later, in a separate phase, judge the truth of those claims in isolation. This temporal separation of photos and judgements was designed to reduce awareness of the photo’s influence when judging claims, thereby increasing the photo-truthiness effect. Across six preregistered experiments, the effect of separating photo presentation from truth judgments on the truthiness effect was tested. Results confirmed that claims with photos were more often judged as true than claims without photos. However, there was no evidence that the 2-phase procedure produced a significantly larger effect than the 1-phase procedure. Item-level analyses revealed that some statements were more susceptible to truthiness effects than others, and in some cases, the presence of a photo even reduced reported truth (a “falsiness” effect). Response time analyses provided some support that truth judgments were more strongly influenced by photos when participants made rapid decisions, consistent with the idea that truthiness is driven by fluency rather than deliberate iv reasoning. These findings suggest that the cognitive mechanisms underlying truthiness - such as fluency and source-monitoring errors - are relatively stable and may depend more on the specific items being judged than on the temporal presentation of photos.