Le président américain Donald Trump a fait de fausses allégations de fraude électorale généralisée lors de l'élection présidentielle de 2020. Les chercheurs en psychologie de l'UNSW ont maintenant trouvé un moyen pour que les gens ne soient pas trompés par de soi-disant «fausses nouvelles» provenant d'une source unique. Crédit :Shutterstock
Si plus de gens vous disaient que quelque chose est vrai, vous penseriez que vous auriez tendance à le croire.
Pas selon une étude de 2019 de l'Université de Yale qui a révélé que les gens croient qu'une seule source d'information se répète sur de nombreux canaux (un "faux consensus"), tout aussi facilement que plusieurs personnes leur disent quelque chose basé sur de nombreuses sources originales indépendantes (un 'véritable consensus').
La découverte a montré comment la désinformation peut être renforcée, et elle a eu des ramifications pour les décisions importantes que nous prenons sur la base des conseils que nous recevons d'endroits tels que les gouvernements et les médias sur des informations telles que les vaccinations, le port de masques pendant la pandémie, ou même pour qui nous votons lors d'une élection. .
La découverte de «l'illusion du consensus» de 2019 a fasciné Saoirse Connor Desai, associée de recherche postdoctorale à l'École de psychologie des sciences de l'UNSW, qui a testé la découverte de l'illusion et trouvé un moyen pour que les gens ne soient pas trompés par de soi-disant «fausses nouvelles» d'un source unique.
L'étude de son équipe a été publiée dans Cognition .
"Nous avons constaté que l'illusion peut être réduite lorsque nous donnons aux gens des informations sur la façon dont les sources originales ont utilisé les preuves pour arriver à leurs conclusions", déclare le Dr Connor Desai.
Elle dit que la découverte est particulièrement pertinente pour les meilleures pratiques de communication scientifique, par exemple. comment les décideurs politiques ou les médias présentent aux gens des preuves ou des recherches scientifiques d'experts.
Par exemple, plus de 80 % des blogs qui démentent le changement climatique répètent les affirmations d'une seule personne qui prétend être un « expert en ours polaires ».
"Vous pourriez avoir une situation où une proposition de santé trompeuse est répétée par plusieurs canaux, ce qui pourrait inciter les gens à se fier à cette information plus qu'ils ne le devraient, parce qu'ils pensent qu'il y a des preuves pour cela, ou ils pensent qu'il y a un consensus", dit le Dr Connor Desai.
"Mais notre découverte montre que si vous pouvez expliquer aux gens d'où proviennent vos informations et comment les sources originales sont parvenues à leurs conclusions, cela renforce leur capacité à identifier un "véritable consensus"."
Le Dr Connor Desai dit que la découverte de l'étude de Yale l'a surprise, "parce qu'elle semblait être une mise en accusation de la capacité humaine à faire la distinction entre un vrai consensus et un faux consensus."
"L'étude originale a montré que les gens sont régulièrement mauvais dans ce domaine. Il y a eu de nombreuses situations où ils ne sont jamais capables de faire la différence entre un vrai et un faux consensus", dit-elle.
"C'est problématique parce que si les gens entendent les déclarations fausses ou trompeuses d'une seule personne répétées par différents canaux, ils pourraient penser que la déclaration est plus valable qu'elle ne l'est."
Dr. Connor Desai says an example of this is multiple independent experts agreeing that Ivermectin should not be used to treat COVID-19 (true consensus), versus a single group or individual saying that people should use it as an anti-viral drug (false consensus).
How the study was conducted
The aim of the UNSW study was to understand why people believe false information when it's repeated.
"Our main goal was to establish whether one reason that people are equally convinced by true and false consensus is that they assume that different sources share data or methodologies," Dr. Connor Desai says.
"Do they understand there is potentially more evidence when you have multiple experts saying the same thing?"
The UNSW researchers conducted several experiments.
The first experiment replicated the 2019 Yale study, which saw participants given a variety of articles about a fictional tax policy which took positive, negative, or neutral stances, and then asked to what extent they agreed the proposal would improve the economy.
It replicated the "illusion of consensus" where people are equally convinced by one piece of evidence as they are by many pieces of evidence but added a new condition where they told people who saw a "true consensus" that the sources had used different data and methods to arrive at their conclusions.
An example of the made up Twitter posts used in the study.
The result was a reduction in the illusion of consensus.
"People were more convinced by true consensus than false consensus."
In another experiment, 200 participants were given information about an election in a fictional foreign democratic country.
They were shown fictional Twitter posts from news outlets that said which candidates would get more votes in the election:some sourced the same or different pollsters to predict a candidate would win, while another tweet said a different contender would win.
But in the true consensus Twitter posts, they gave people a scenario in which it was clear that different primary sources worked independently and used different data to arrive at their conclusions.
"We expected that many people would be more familiar with such polls and would realize that looking at multiple different polls would be a better way of predicting the election result than just seeing a single poll multiple times," Dr. Connor Desai says.
After reading the tweets, participants rated which candidate would win based on the polling predictions.
"It seemed that people were more convinced by a true consensus than a false consensus when they understood the pollsters had gathered evidence independently of one another," Professor of Cognitive Psychology in the School of Psychology, Brett Hayes says.
"Our results suggest that people do see claims endorsed by multiple sources as stronger when they believe these sources really are independent of one another."
The researchers later replicated and extended the tweet study with 365 more participants.
"This time we had a condition where the tweets came from individual people who showed their endorsement of the polls using emojis," Dr. Connor Desai says.
"Regardless of whether the tweets came from news outlets, or individual tweeters, people were more convinced by true than false consensus when the relationship between sources was unambiguous."
False consensus not completely discounted
But the researchers also found the participants didn't completely discount false consensus.
"There are at least two possible explanations for this effect," Dr. Connor Desai said.
"The first is that such repetition simply increases the familiarity of the claim—enhancing its memory representation, and this is sufficient to increase confidence.
"The second is that people may make inferences about why a claim is repeated because the source believed it was the most reputable or provided the strongest evidence.
"For instance, if different news channels all cite the same expert you might think that they're citing the same person because they are the most qualified to talk about whatever it is they're talking about."
Dr. Connor Desai plans to next look at why some communication strategies are more effective than others, and if repeating information is always effective.
"Is there a point where there's too much consensus, and people become suspicious?" she says.
"Can you correct a 'false consensus' by pointing out that it's often better to get information from multiple independent sources? These are the kinds of strategies we wish to look into."
