Psychological booster shots targeting memory increase long-term resistance against misinformation

Abstract

An increasing number of real-world interventions aim to preemptively protect or inoculate people against misinformation. Inoculation research has demonstrated positive effects on misinformation resilience when measured immediately after treatment via messages, games, or videos. However, very little is currently known about their long-term effectiveness and the mechanisms by which such treatment effects decay over time. We start by proposing three possible models on the mechanisms driving resistance to misinformation. We then report five pre-registered longitudinal experiments (N_total = 11,759) that investigate the effectiveness of psychological inoculation interventions over time as well as their underlying mechanisms. We find that text-based and video-based inoculation interventions can remain effective for one month-whereas game-based interventions appear to decay more rapidly-and that memory-enhancing booster interventions can enhance the diminishing effects of counter-misinformation interventions. Finally, we propose an integrated memory-motivation model, concluding that misinformation researchers would benefit from integrating knowledge from the cognitive science of memory to design better psychological interventions that can counter misinformation durably over time and at-scale.

Fig. 1. Experimental design flowcharts for studies 1–5.

Flowcharts of the procedure participants went through in text-based Study 1 (A topic: climate change), gamified Study 2 (B topic: six often used misinformation techniques), and video-based Studies 3–5 (C topic: misinformation using emotional language). Each rectangle represents a stage of the study. The arrows depict the order of procedure for participants. Branching means participants were randomly allocated to a path. Pretests and posttests refer to the measurement of inoculation effects.

Fig. 2. Theoretical models explaining the long-term effectiveness of inoculation.

Three theoretical models to explain the long-term effectiveness of inoculation, a motivation-based model (Model A), a memory-based model (Model B), and a combined memory-motivation (Model C). Threat and motivation related variables are presented with a blue background. Memory-related variables are presented with a red background.

Fig. 3. Perceived scientific consensus, memory, and motivation over time for each group in study 1.

A, C, and E show the smoothed trends of perceived scientific consensus (representing the inoculation effect), memory (recall of the inoculation intervention), and motivation (to resist misinformation) over time, respectively, for three groups (Control in red, Inoculation in green, and Booster in blue). The error bands represent 95% confidence intervals around the mean. B, D, and F display the group means at specific time points (Pre, 0, 8, and 29 days after inoculation). The error bars represent 95% confidence intervals, and the center of each bar represents the mean. The sample size for the study is N = 1825.

Fig. 4. Fake news unreliability ratings, memory, and motivation over time for each group in study 2.

A, C, and E show the smoothed trends of fake news unreliability ratings (representing the inoculation effect), memory (recall of the inoculation intervention), and motivation (to resist misinformation) over time, respectively, for three groups (Control in red, Inoculation in green, and Booster in blue). The error bands represent 95% confidence intervals around the mean. B, D, and F display the group means at specific time points (Pre, 0, 9, and 29 days after inoculation). The error bars represent 95% confidence intervals, and the center of each bar represents the mean. The sample size for the study is N = 674.

Fig. 5. Manipulativeness discernment, memory, and motivation over time for each group in study 5.

A, C, and E show the smoothed trends of manipulativeness discernment (representing the inoculation effect), memory (recall of the inoculation intervention), and motivation (to resist misinformation) over time, respectively, for five groups (Control + Control in red, Inoculation + Control in olive green, Inoculation + Inoculation in teal green, Inoculation + Threat Booster in blue, and Inoculation + Memory Booster in purple). The error bands represent 95% confidence intervals around the mean. B, D, and F display the group means at specific time points (0 and 29 days after inoculation), and follow the same color mapping as the panels on the left. The error bars represent 95% confidence intervals, and the center of each bar represents the mean. The sample size for the study is N = 2220.

Fig. 6. The memory-motivation model of inoculation in study 5.

This figure represents the direct and indirect effects of inoculation on the discernment of manipulative items from neutral items (Discernment) at ~30 days after the intervention (T30), through objective memory recall (Memory) and subjective motivation to defend oneself against misinformation (Motivation) immediately after the intervention (T0) and ~30 days after the intervention (T30). It also depicts the effects of a memory-boosting intervention and a threat-boosting intervention administered ~10 days after the intervention (T10). An equivalent model for text-based inoculation (Study 1) and gamified inoculation (Study 2) can be found in Supplementary Figs. 1 and 3 respectively. However, the model presented here is the most complete as it separates memory and threat boosters. N = 2220.