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Friday, September 15, 2023

Older Americans are more vulnerable to prior exposure effects in news evaluation.

Lyons, B. A. (2023). 
Harvard Kennedy School Misinformation Review.


Older news users may be especially vulnerable to prior exposure effects, whereby news comes to be seen as more accurate over multiple viewings. I test this in re-analyses of three two-wave, nationally representative surveys in the United States (N = 8,730) in which respondents rated a series of mainstream, hyperpartisan, and false political headlines (139,082 observations). I find that prior exposure effects increase with age—being strongest for those in the oldest cohort (60+)—especially for false news. I discuss implications for the design of media literacy programs and policies regarding targeted political advertising aimed at this group.

Essay Summary
  • I used three two-wave, nationally representative surveys in the United States (N = 8,730) in which respondents rated a series of actual mainstream, hyperpartisan, or false political headlines. Respondents saw a sample of headlines in the first wave and all headlines in the second wave, allowing me to determine if prior exposure increases perceived accuracy differentially across age.  
  • I found that the effect of prior exposure to headlines on perceived accuracy increases with age. The effect increases linearly with age, with the strongest effect for those in the oldest age cohort (60+). These age differences were most pronounced for false news.
  • These findings suggest that repeated exposure can help account for the positive relationship between age and sharing false information online. However, the size of this effect also underscores that other factors (e.g., greater motivation to derogate the out-party) may play a larger role. 
The beginning of the Implications Section

Web-tracking and social media trace data paint a concerning portrait of older news users. Older American adults were much more likely to visit dubious news sites in 2016 and 2020 (Guess, Nyhan, et al., 2020; Moore et al., 2023), and were also more likely to be classified as false news “supersharers” on Twitter, a group who shares the vast majority of dubious news on the platform (Grinberg et al., 2019). Likewise, this age group shares about seven times more links to these domains on Facebook than younger news consumers (Guess et al., 2019; Guess et al., 2021). 

Interestingly, however, older adults appear to be no worse, if not better, at identifying false news stories than younger cohorts when asked in surveys (Brashier & Schacter, 2020). Why might older adults identify false news in surveys but fall for it “in the wild?” There are likely multiple factors at play, ranging from social changes across the lifespan (Brashier & Schacter, 2020) to changing orientations to politics (Lyons et al., 2023) to cognitive declines (e.g., in memory) (Brashier & Schacter, 2020). In this paper, I focus on one potential contributor. Specifically, I tested the notion that differential effects of prior exposure to false news helps account for the disjuncture between older Americans’ performance in survey tasks and their behavior in the wild.

A large body of literature has been dedicated to exploring the magnitude and potential boundary conditions of the illusory truth effect (Hassan & Barber, 2021; Henderson et al., 2021; Pillai & Fazio, 2021)—a phenomenon in which false statements or news headlines (De keersmaecker et al., 2020; Pennycook et al., 2018) come to be believed over multiple exposures. Might this effect increase with age? As detailed by Brashier and Schacter (2020), cognitive deficits are often blamed for older news users’ behaviors. This may be because cognitive abilities are strongest in young adulthood and slowly decline beyond that point (Salthouse, 2009), resulting in increasingly effortful cognition (Hess et al., 2016). As this process unfolds, older adults may be more likely to fall back on heuristics when judging the veracity of news items (Brashier & Marsh, 2020). Repetition, the source of the illusory truth effect, is one heuristic that may be relied upon in such a scenario. This is because repeated messages feel easier to process and thus are seen as truer than unfamiliar ones (Unkelbach et al., 2019).