Investigating the role of the Illusory Truth Effect and the Directed Forgetting Paradigm in Truthfulness perceptions of populist political speeches

By Laura De Carvalho, Brazil

Abstract:

The political scenario of the 21st century is marked by profound polarization, prominently featuring the rise of populist politicians who employ various rhetorical techniques and spread misinformation, manipulating public opinion. This study investigates the influence of repetition in the perception of populist messages, focusing on their truthfulness ratings, through the Directed Forgetting Paradigm, alongside a comprehensive set of variables. It seeks to determine whether repeated exposure to populist claims enhances perceived truthfulness, even under directed forgetting conditions, examining the resilience of emotionally charged claims compared to neutral ones, and exploring whether participants are likely to rate repeated assertions as more truthful when they align with their political beliefs. The research analyzes speeches by populist leaders in Brazil and the United States, aiming to contribute to understanding mass manipulation in a globalized context, underline the need for critical engagement with populist rhetoric, and use the Directed Forgetting Paradigm to mitigate this problem.

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Introduction:

Initially associated with Latin America in the 1990s and new post-communist democracies in the 2000s, populist parties and politicians have now gained support and power in democracies as well. Populist speeches always include emotional and appellative factors, leading to the manipulation of the masses and building a harmful political environment [7]. Different from past research, this study will follow a different path in the analysis of the Illusory Truth Effect (ITE) and the Directed Forgetting Paradigm (DFP), focusing on a political framing and a more comprehensive set of variables to ensure reliable results. Within this context, the ITE and the DFP emerge as powerful cognitive mechanisms that may jointly explain how repeated and emotionally charged messages can shape and distort public perceptions of truth [3][4][5]. The current study aims to address this by examining how these mechanisms interact to influence perceived truthfulness in populist discourse in a location-based approach.

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Literature Review:

The Illusory Truth Effect (ITE), originally defined by Hasher et al. (1977) [5], refers to the judgment of repeated statements as more truthful than new ones, independent of their accuracy, suggesting that repetition enhances processing ease and is misattributed to truthfulness (Fazio et al., 2015) [4]. In contrast, the Directed Forgetting Paradigm (DFP) derives from cognitive psychology research on intentional memory suppression, demonstrating that individuals can intentionally forget information, often with effects on recall and cognitive interference (Bjork, 1998; Sahakyan & Kelley, 2002) [1][8].

The intersection between ITE and DFP is especially relevant when analyzing populist political communication, which frequently relies on repetition, simplification, and emotional amplification to create persuasive narratives (Mudde & Kaltwasser, 2017) [7]. By encouraging selective recall through rhetorical distraction, such speeches may inadvertently, or deliberately, invoke cognitive processes akin to directed forgetting. Through research on misinformation and belief persistence, Ecker et al. (2010) [3] found that even when corrected, false information tends to persist in memory, a phenomenon also related to the ITE and failures in belief updating. These effects has been explored extensively in media contexts, still, implications for political speech, particularly populist speech, remain underexplored, even though it can be a differential in investigating how certain elements in a political message may be deliberately designed to divert attention or suppress critical information processing, thus influencing what is remembered and rated as true.

Methodology:​ 

The sample will be selected randomly, and all of them must be in the 20-35 age range. A sample of 120 adults and university students will be recruited via a stratified random sampling, ensuring diversification of gender, political background, and age. Individuals with diagnosed cognitive or memory impairments or who express complete disinterest in politics will be excluded.

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The study will use a quasi-experimental, within-subjects design using a 3-way factorial structure. The three independent variables will be repetition (repeated vs. novel statements), forgetting instruction (remember vs. forget cues), and emotional intensity (emotionally charged vs. neutral claims). An additional between-subjects factor, political alignment, will be determined based on participants’ self-reported political orientation to assess congruence between individual beliefs and the content of the political claims, analysing their truthfulness ratings based on political views. The dependent variables will include perceived truthfulness, measured on a 5-point Likert scale, and memory performance, assessed via free recall and recognition tasks [2][6].

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For this experiment, the stimuli used will be 24 short populist claims (15–20 words), sourced and adapted from real-world speeches (neutral, left- and right-wing). Each of the claims will be categorized by emotional valence (e.g., emotionally loaded vs. neutral) using pilot ratings and labeled based on participant political congruence pre-test classification.

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First, participants will complete a demographic and political orientation questionnaire. Participants will receive an assessment form to declare their political positions, on a 1-7 scale, and they’ll mark the options that most resonate with their views. Their answers will be kept until the end of the test and used in further analysis of the results. In the second phase (baseline), they will view 12 claims and rate their perceived truthfulness using a Likert scale ranging from 1 (Not at all truthful) to 5 (Completely truthful). The speeches that participants will receive will be randomly selected, following an equal number of left-oriented, right-oriented, and neutral stimuli. Next, participants will view all 24 claims, including the 12 repeated from phase two and 12 new ones. After each claim, they will see either a “REMEMBER” or a “FORGET” cue, following the item-method DFP protocol [1]. Each claim will again be rated for truthfulness. Finally, in the final phase, participants will complete a memory recall task, listing all claims they remember (free recall), and complete a recognition task to identify whether they had seen a set of 36 statements (24 old, 12 new).

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Moreover, factorial ANOVAs (Repetition × Emotion × Instruction) and multiple regression models would be used to analyze the results. 2x2 ANOVA will examine repetition and forgetting on truth ratings, the interaction between emotional intensity and forgetting cues on recall, and truthfulness. The relation between politically congruent, emotionally intense, repeated claims and truthfulness ratings will be analyzed through a moderated regression model, including interaction terms. Where applicable, post hoc t-tests will explore significant differences between groups. Optionally, qualitative data collected from participants’ open-ended justifications for their ratings may be coded thematically to explore cognitive reasoning patterns.

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For ethical considerations, all participants will be required to provide informed consent, will be assured of their right to withdraw at any point, and details about the research. Then, at the end of the experiment, they will get a full debriefing post-study to correct misinformation exposure. Besides, all the information shared by the participants will remain confidential, and they have the right to withdraw from the experiment at any stage, as a voluntary activity [3][4][7].

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References :

1. Bjork, R. A. (1998). Intentional forgetting in perspective: Comments, conjectures, and some directed remembering. In J. M. Golding & C. M. MacLeod (Eds.), Intentional forgetting: Interdisciplinary approaches (pp. 453–481). Lawrence Erlbaum Associates.

2. Creswell, J. W. (2014). Research design: Qualitative, quantitative, and mixed methods approaches (4th ed.). SAGE Publications.

3. Ecker, U. K. H., Lewandowsky, S., Swire, B., & Chang, D. (2010). Correcting false information in memory: Manipulating the strength of misinformation encoding and its retraction. Psychonomic Bulletin & Review, 18(3), 570–578. https://doi.org/10.3758/s13423-011-0065-1

4. Fazio, L. K., Brashier, N. M., Payne, B. K., & Marsh, E. J. (2015). Knowledge does not protect against illusory truth. Journal of Experimental Psychology: General, 144(5), 993–1002. https://doi.org/10.1037/xge0000098

5. Hasher, L., Goldstein, D., & Toppino, T. (1977). Frequency and the conference of referential validity. Journal of Verbal Learning and Verbal Behavior, 16(1), 107–112. https://doi.org/10.1016/S0022-5371(77)80012-1

6. Johnson, R. B., & Onwuegbuzie, A. J. (2004). Mixed methods research: A research paradigm whose time has come. Educational Researcher, 33(7), 14–26. https://doi.org/10.3102/0013189X033007014

7.Mudde, C., & Kaltwasser, C. R. (2017). Populism: A very short introduction. Oxford University Press.

8. Sahakyan, L., & Kelley, C. M. (2002). A contextual change account of the directed forgetting effect. Journal of Experimental Psychology: Learning, Memory, and Cognition, 28(6), 1064–1072. https://doi.org/10.1037/0278-7393.28.6.1064

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