Repetition boosts belief in climate-skeptical claims, even among climate science endorsers
A single repetition increased the claims’ perceived truth for the strongest climate science supporters surveyed
PLOS
image:
Estimated mean truth ratings across repetition (repeated, non-repeated) and claim type (science-aligning, skeptic-aligning) in Experiment 1. Note. Error bars show 95% CI.
view moreCredit: Jiang et al. 2024, PLOS ONE, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
Climate science supporters rated climate-skeptical statements as “truer” after just a single repetition, according to a study published August 7, 2024 in the open-access journal PLOS ONE led by Mary Jiang from The Australian National University, Australia, and coauthored by Norbert Schwarz from the University of Southern California, USA, and colleagues. The results held true even for the strongest climate science supporters surveyed.
Amidst the influx of content that a person consumes each day, the principle of motivated cognition suggests they are likelier to find truth in the statements that mirror their own beliefs. However, a second phenomenon, the illusory truth effect, suggests that just one repeated exposure to an idea — regardless of what it is — can elevate its perceived validity.
Schwarz and colleagues examined these ideas in the arena of climate science, questioning how self-identified climate science supporters might react when repeatedly exposed to climate-skeptical claims. Would repetition have an effect despite the conviction of their own beliefs?
The researchers fashioned two similar experiments, the first including 52 participants and the second 120. At least 90% of participants across both experiments endorsed climate science: the scientific evidence of human-caused climate change.
Participants reviewed a series of statements classified as climate-skeptical, climate-science, or weather-related filler statements. After 15 minutes, they reviewed a second series of claims, half of which were repetitions of the previous statements. They rated the claims from “Definitely True” to “Definitely False” on a six-point Likert scale. In Experiment 2, the participants also classified each claim as scientist- or skeptic-aligned, and defined their own climate views using the Six Americas Super Short Survey.
In the climate science endorsers, the repetition did increase perceived validity of all claim types — including the ones participants flagged retrospectively as antithetical to their own beliefs. This held true even for the strongest climate science supporters, those participants who self-identified as “Alarmed” by climate change.
These results reinforce the benefits of amplifying truth by repetition and the risks of spreading false information, the researchers write. They suggest that further studies include non-climate issues (e.g., immigration, education, healthcare, etc.), experiment with time spans and rounds of repetition, and invert the experiment to study how climate skeptics are affected by repetition of claims supporting climate science.
Lead author Mary Jiang adds: “People find claims of climate skeptics more credible when they have been repeated just once. Surprisingly, this increase in belief as a result of repetition occurs even when people identify as a strong endorser of climate science.”
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In your coverage please use this URL to provide access to the freely available article in PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0307294
Citation: Jiang Y, Schwarz N, Reynolds KJ, Newman EJ (2024) Repetition increases belief in climate-skeptical claims, even for climate science endorsers. PLoS ONE 19(8): e0307294. https://doi.org/10.1371/journal.pone.0307294
Author Countries: Australia, USA
Funding: The author(s) received no specific funding for this work.
Journal
PLoS ONE
Method of Research
Experimental study
Subject of Research
People
Article Title
Repetition increases belief in climate-skeptical claims, even for climate science endorsers
Article Publication Date
7-Aug-2024
‘Fuel to the fire’: repeated climate-sceptic claims enough to nudge even the strongest of climate change endorsers
The threat of misinformation runs rampant in our digital age, where a single repetition of a climate-sceptical claim seems more true even to the staunchest of climate change endorsers, according to a new study from The Australian National University (ANU).
The researchers investigated whether repeated exposure to a climate-sceptic claim from a single source increases the perceived truth of that claim even when the claim runs counter to the receiver’s own climate change beliefs.
ANU PhD student and study lead author, Mary Jiang, said although study participants were more inclined to believe climate scientist-aligned claims over climate sceptic or climate denial claims, the power of repetition carries dangerous weight.
“More than 90 per cent of the study participants endorse climate science. While participants perceived claims aligned with climate scientists to be more truthful than claims aligned with climate scepticism, both types of claims seemed truer when repeated,” she said.
“This increase in perceived truth after repetition occurred even for groups highly concerned about climate change, and when people could later identify that the claim supports the other side.”
According to Ms Jiang, climate-sceptic claims may be presented alongside scientific facts in the name of ‘balanced’ reporting.
“Giving equal exposure to opposing voices makes it sound like the evidence and number of people in favour of each view is also equal. But most, if not all, climate scientists agree on human-induced climate change,” Ms Jiang said.
“While balanced reporting ensures fairness, it does not always paint an accurate or helpful picture and can add fuel to the fire.”
With recent figures suggesting that 89 per cent of people worldwide want more political action on climate change, the researchers warn of the insidious effect of repetition in making climate-sceptic arguments more credible, which in turn, puts everyone at risk of misinformation.
“When we used participants’ own classifications ensuring that they could later categorise a claim as sceptic-aligning, our climate science endorsing participants still considered repeated sceptic-aligning claims to be more truthful,” Ms Jiang said.
“Our study shows that repeat exposure to a claim from a single source is enough to nudge recipients towards acceptance of the repeated claim, even when their attitudes are aligned with climate science and that claim counteracts their beliefs.”
Study co-author, ANU Associate Professor Eryn Newman, said the findings shed light on our vulnerability to the simple repetition of claims.
“A feeling of familiarity is not a reliable cue to truth in digital environments where bots and other mechanisms can lead to a broad spread of false or misleading claims,” she said.
“When you look at the broader literature, being smarter or more critical in the analysis of information does not seem to protect people from shifts in belief because of repetition.
“This speaks to the important role of the ‘health’ of the information environment in which we engage.”
The researchers say it’s not all bad news.
“Study participants rated claims that were aligned with climate scientists as more true when they were repeated than when they were not, implying that it is beneficial to repeat claims that have scientific consensus, even when recipients are already in agreement with it,” Ms Jiang said.
Further research is needed to understand whether repeating counter-attitudinal information has similar effects on other samples, such as climate sceptics, who were underrepresented in the study. The researchers also want to find out whether repeating misleading claims can influence people who hold divided beliefs and attitudes on issues such as immigration, education and healthcare.
“The bottom line is, we should be cautious about repeating false information. Instead, repeat what is true and enhance its familiarity,” Associate Professor Newman said.
The research team also includes experts from the University of Southern California and the University of Melbourne.
The study is published in PLOS.
Method of Research
Survey
Subject of Research
People
Article Title
Repetition increases belief in climate-skeptical claims, even for climate science endorsers
Article Publication Date
8-Aug-2024
