Date of Award

8-8-2024

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Psychology

First Advisor

Sarah Barber

Abstract

As people get older, they are more likely to view, share, and engage with misinformation online. For example, during the 2016 U.S. presidential campaign, people aged 65 and above shared seven times more fake news articles and were twice as likely to be exposed to fake news articles on Facebook, as compared to people aged 18 to 29. This raises the important question of how to reduce older adults’ belief in misinformation and fake news. Surprisingly, although interventions have been developed to combat the spread of misinformation, almost no research has tested their effectiveness with older adults. This study tested the effectiveness of psychological inoculation in reducing belief in misinformation for younger and older adults. It is also unknown whether inoculation interventions are effective when misinformation is repeated, due to repeated information being rated as truer than new information, known as the illusory truth effect. This study had three aims: (1) To determine if the effectiveness of inoculation techniques changes with age, (2) to determine if inoculation is effective at reducing the illusory truth effect for younger and older adults, and (3) to determine if the magnitude of the illusory truth effect differs with age. To test these aims, older and younger adult participants were randomly assigned to either receive an inoculation treatment addressing a misinformation technique or they received no intervention. Participants then completed a social media exposure phase where they saw both neutral and manipulative social media posts. Immediately and after a two-week delay participants rated perceived truth of repeated and new headlines. Threat and counterarguing, two proposed mediators for inoculation, were measured during both rating phases. The illusory truth effect was replicated, and the magnitude of the effect was larger for older adults than younger adults. However, the inoculation intervention was not effective in reducing belief in misinformation or in reducing the magnitude of the illusory truth effect. Although inoculation was not related to either threat or counterarguing, counterarguing was consistently associated with higher discernment between true and false headlines. This suggests that counterarguing is an important mechanism for improving discernment.

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