Researcher Zhang asked participants to evaluate a claim while being exposed to either photos of the subject of the claim (which, in this case, was Betal or Shrimp) or photos of the referent (Leghorn or Rose). 

If the illusion of evidence is the reason for the truthiness effect, either photo should bias people to believe the claim as true. 

On the other hand, if the truthiness effect is due to the fluency perspective, photos of the subject should produce truthiness, whereas photos of the referent should produce falsiness. 

Zhang found that the latter results occurred, therefore providing no evidence for the illusion of evidence reasoning for the truthiness effect and more evidence for the fluency reasoning. 


Evidence for the fluency reasoning and against the illusion of evidence reasoning for truthiness:

- Photos are believed to be inherently credible because they often do not know how to detect when a photo has been altered
- Newman et al. (2012) examined whether people would believe claims accompanied only by photos, or whether they would also believe claims accompanied by other forms of non-probative information
- One group of subjects received celebrity names paired with photos of the celebrities, while the other half received celebrity names were paired with a verbal description of the celebrity

Evidence For Why Trust in Photos Can Produce Truthiness

- photos are inherently trustworthy
- people's judgments are swayed via a cognitive fluency mechanism, facilitating the semantic processing of a claim
- the inclusion of photos, despite being non-probative, creates an illusion of evidence

University of Michigan - Ann Arbor

Non-probative photos are photos related to some information without any characteristic of proof functioning as decoration.

non-probative photos

Newman, E. J., & Zhang, L. (2020). Truthiness: How non-probative photos shape belief. In R. Greifeneder, M. Jaffé, E. J. Newman, & N. Schwarz (Eds.), The psychology of fake news: Accepting, sharing, and correcting misinformation (pp. 90–114). London: Routledge. 

Truthiness: How non-probative photos shape belief

The effect in which a non-probative photo has an impact on people's beliefs about the truth of an associated claim, despite the fact that the photo provides no diagnostic evidence for the claim's truthfulness.

The Truthiness Effect

Possible reasons why non-probative photos sway people’s judgments:

People were swayed to believe an associated claim was false due to this effect in which semantically unrelated photos should have interfered with conceptual processing of the claim.

Falsiness Effect

The exposure to non-probative photos causes people to overestimate how familiar they are with stimuli shown on the photo (Wilson & Westman, 2018) and how much they know about a process in which the stimuli is involved (Cardwell et al., 2017).

Learn Before

Related

Learn After