The Roles of Conspiracy Theories and Political Participation on Justifying Violence in the Capitol Hill Riots

Abstract

We investigated the relationship between conspiracy theories, political participation, and justification of political violence during the 2021 Capitol Hill riots in two studies. Study 1 was a correlational survey of participants who voted for Trump in 2020, measuring their conspiracy mentality, belief in the 2020 U.S. presidential election fraud conspiracy theory, political participation, and justification of the violence used during the Capitol Hill riots. Results indicated that justification of violence was highest among politically active participants who also believed conspiracy theories. In Study 2, we manipulated exposure to election fraud conspiracy theories, again in a sample of U.S. participants who had voted for Trump. Although our manipulation produced no main effect, we found a similar interaction with a measure of political participation in predicting justification of violence. We conclude that political participation predicts justification of violence, especially among those who believe in or are exposed to ideologically congruent conspiracy theories.

Keywords

conspiracy theories political participation political violence Capitol Hill riots collective action

On January 6, 2021, the world was stunned as a mob of violent protesters stormed the Capitol building in Washington, D.C., in an attempt to overthrow the certification of President-elect Joe Biden. These Capitol Hill riots led to vandalism, threats against politicians, and clashes with law enforcement, resulting in five deaths and numerous injuries (Das et al., 2023; Lonsdorf et al., 2022). While the Capitol Hill riots could be considered a form of political participation, political participation often occurs peacefully and is considered beneficial for a democratic society. What determines if political participation turns violent? We propose that conspiracy theories play an important role in this process. Indeed, a key motivation for the Capitol Hill riots was the conspiracy theory alleging election fraud in favor of Joe Biden (Ntontis et al., 2023), and many rioters included QAnon adherents, a far-right conspiratorial movement (Biesecker et al., 2021; Miller, 2023). The present study aimed to explore the links between conspiracy theories, political participation, and support for political violence against the background of the Capitol Hill riots.

Political Participation

Many people in a democratic society are politically active. However, political participation is not always in line with democratic principles and the rule of law. Political action may be normative, referring to political participation that adheres to social norms and the rule of law. Examples of normative political action include voting in elections, joining a political party, petitioning, and participating in peaceful protests. Sometimes people may resort to nonnormative political action instead, which refers to illegal expressions of political participation. Examples of nonnormative political participation include sending hate mail or death threats to public figures, demolishing property, and other violent forms of protest (Imhoff et al., 2021).

Nonnormative political action and anti-government sentiments are pressing issues today. Research has shown a significant increase in anti-government protests, rising by approximately 12% per year in Europe and 17% per year in North America from 2009 to 2019 (Brannen et al., 2020). As the Capitol Hill riots have underscored, even when collective political protests start peacefully, they may escalate into violent clashes with law enforcement. Research also shows that conspiracy theories are closely coupled with nonnormative forms of protest (Imhoff et al., 2021), and specifically with violent ones (Rottweiler & Gill, 2020). Conspiracy theories may therefore be important to understand when political participation turns violent.

The Role of Conspiracy Theories

Conspiracy theories are commonly defined as the belief that a group of actors join in secret agreement to achieve a hidden and unlawful goal (Douglas & Sutton, 2023; van Prooijen & van Vugt, 2018). Belief in conspiracy theories has a complicated relationship with people’s willingness to be politically active. Highly politically active individuals often hold stronger conspiracy beliefs (Jiang, 2023). In addition, conspiracy mentality—a general tendency to view events in the world as the result of conspiracies—is a positive predictor of people’s intention to engage in protesting behavior (Imhoff & Bruder, 2014). Conspiracy theories do not always positively predict political participation, as they also predict political withdrawal behaviors such as reduced intentions to vote (Jolley & Douglas, 2014). Moreover, evidence suggests that the link between conspiracy beliefs and political engagement is curvilinear, with the highest level of political engagement at intermediate levels of conspiracy beliefs (Imhoff et al., 2021).

These seemingly contradictory findings can be reconciled by distinguishing between normative versus nonnormative forms of collective action. Conspiracy theories have been found to increase intentions to engage in nonnormative political actions while decreasing intentions to engage in normative political actions (Imhoff et al., 2021; cf. Uscinski et al., 2021; but see Klofstad et al., 2025). One possible explanation is that normative political actions may be seen as useless to people who believe that the world is run by evil conspiracies (Wood, 2016). Moreover, conspiracy beliefs portray an outgroup (e.g., political elites) as dangerous, promoting a willingness to fight (van Prooijen, 2024). Accordingly, conspiracy beliefs predict an increased willingness to justify political violence, legitimize radical political action, and endorse violence as a means to an end (Jolley et al., 2019; Vegetti & Littvay, 2022). Conspiracy beliefs also predict a rejection of the political status quo and diminished support for representative democracy, suggesting a willingness to abandon democratic principles in decision-making (Papaioannou et al., 2024).

These effects emerge for both general conspiracy mentality and belief in specific conspiracy theories. A study showed that a wide range of conspiracy theories are positively correlated with increased support of political violence and self-reported engagement in political violence (Enders et al., 2024). For example, belief in the Great Replacement Theory predicts increased persecution of Muslims, violent intentions, and Islamophobia (Obaidi et al., 2022). Similarly, both specific conspiracy beliefs (notably, the belief that 5G radiation caused the COVID-19 pandemic) and a general conspiracy mentality are positively associated with justification and willingness to use violence, violent attacks on 5G masts, and anti-government protests (Jolley & Paterson, 2020; Šrol et al., 2022). Regarding the Capitol Hill riots, one study found that support for the QAnon conspiratorial movement was one of the best predictors of support for the violence used in the riots (Armaly et al., 2022). Thus, conspiracy theories have many detrimental effects on society in the form of nonnormative political actions, including aggression, radicalization, and increased violent extremist intentions (Diethelm & McKee, 2009; Rottweiler & Gill, 2020; van Prooijen & van Vugt, 2018). It is therefore likely that conspiracy theories are important to understand when political participation predicts a justification of violent means.

The Current Research

In this study, we investigated whether conspiracy theories can predict how political participation is associated with the justification of political violence. More specifically, we sought to understand the conditions under which normative political participation may turn into support for nonnormative violent action, and hypothesize that conspiracy theories might enable this association by framing violence as a justified response. While our measure of political participation captures normative forms of political participation (e.g., voting, attending rallies), we tested whether individuals who are more politically active are more likely to justify political violence when they also believe in conspiracy theories.

Study 1 began as an exploratory investigation into potential moderators and mediators of the relationship between conspiracy theories and justification of violence. Political participation was initially included as an exploratory moderator, and we formulated Hypothesis 1, predicting a positive relationship between conspiracy beliefs and justification of violence. Based on the findings, Study 2 aimed to confirmatively test the interaction between political participation and manipulated election fraud conspiracy beliefs by varying whether participants were exposed to a conspiratorial blog post. Both our findings and theoretical reasoning subsequently led us to refine the model and propose Hypothesis 2, stating that conspiracy theories moderate the relationship between political participation and support for political violence.

We test our model by focusing on a prominent real-life example, namely the 2021 Capitol Hill riots. Specifically, measuring the extent to which voters of Donald Trump in the 2020 presidential elections would justify the violence used in the riots. We focus on Trump voters to ensure ideological congruency between our sample and the protesters, allowing our analyses to capture variation in support for violence within a politically aligned group. While this choice implies a trade-off with generalizability, this approach allows us to test when politically aligned individuals support or reject political violence, and how conspiracy theories influence this decision.

Open Science Practices

Both studies in this article were preregistered on the Open Science Framework (OSF) and can be accessed at https://osf.io/6utwb/overview. The data and analyses for both studies, alongside the supplemental materials, are also available at this link under “files.” Both studies have been approved by the Ethical Review Board, by means of an approved cluster-proposal on conspiracy theories by the last author. All participants provided informed consent.

Study 1

The purpose of Study 1 was to establish that conspiracy theories are related to the justification of violence against one’s own government while also exploring the role of political participation in these effects. In the context of the 2021 Capitol Hill riots, we hypothesized that the specific conspiracy belief that the 2020 U.S. presidential election was rigged to favor the Democratic Party would be positively associated with the justification of violence used during this event (Hypothesis 1). In addition, we expected that conspiracy mentality would be positively associated with the justification of violence used during this event. Furthermore, we examined the interaction effect between political participation and conspiracy beliefs predicting the justification of violence.¹

Method

Participants & Design

We recruited 399 U.S. participants through Prolific, prescreened to include only those who voted for Trump in the 2020 U.S. presidential election. However, 27 participants reported in our survey that they did not meet this criterion and were therefore excluded from further analyses. The final sample consisted of 372 participants, providing 80% power to detect small effect sizes (r = .09, one-sided). The participants consisted of 186 men and 186 women, with ages ranging from 20 to 80 years (M = 46.41, SD = 14.02). This study was a cross-sectional survey. All items were measured on a 7-point scale ranging from “strongly disagree” (1) to “strongly agree” (7) unless specified otherwise. The full scales, including answer options, are available in the supplemental materials.

Dependent Variable

Justification of Violence

We measured participants’ tendency to justify the violence used in the 2021 Capitol Hill riots, with an altered version of the “attitudes toward political violence” scale by Vegetti and Littvay (2022). Each item started with: “to express political discontent, it was acceptable for the rioters in the 2021 U.S. Capitol Riot to …” The scale consisted of six items, including items such as “arm themselves” and “physically harm a government official.” The scale had good internal consistency (α = .82).

Independent Variables

Conspiracy Mentality

We assessed conspiracy mentality using the five-item Conspiracy Mentality Questionnaire by Bruder et al. (2013), including items such as “many very important things happen in the world, which the public is never informed about” and “politicians usually do not tell us the true motives for their decisions.” The scale had good internal consistency (α = .88).

Election Fraud Conspiracy Theory

We measured participants’ belief in the conspiracy theory that the 2020 U.S. presidential election was illegally stolen by the Democratic Party, measured with a four-item scale by Wang and van Prooijen (2023). The scale included items such as “the elections were rigged to favor Joe Biden” and “the Democratic Party was committing fraud in the elections.” The scale had excellent internal consistency (α = .95).

Political Participation

We measured participants’ normative political participation, with an adapted version of the scale by Gil de Zúñiga et al. (2012). The scale consists of 11 items, measured on a 7-point scale ranging from “never” (1) to “all the time” (7). For example, items asked participants how often in the past 12 months they had “written to a politician” or “attended a political rally.” An analysis of the scale revealed excellent internal consistency (α = .95).

Control Variables

The control variables used in this study were demographics, notably age, gender, education (ranging from no education to college graduate), and political orientation (scale ranging from −10 “liberal” to 10 “conservative”).

Results

A correlation matrix containing correlations between all variables, as well as means, standard deviations, and reliabilities, can be seen in Table 1.

Table 1

Means, Standard Deviations, Reliabilities, and Correlations for Study 1 Variables

	M	SD	α	1	2	3	4	5	6	7	8
1. Justification of Violence	2.32	1.14	.82	—
2. Conspiracy Mentality	4.98	1.32	.88	0.22^***	—
3. Election Fraud Conspiracy Beliefs	4.70	1.80	.95	0.29^***	0.66^***	—
4. Political Participation	1.38	0.80	.95	0.35^***	−0.01	−0.01	—
5. Gender	0.50	0.50	—	0.06	−0.17^***	−0.09	0.04	—
6. Education	3.70	0.83	—	0.05	−0.13^*	−0.15^**	0.23^***	0.05	—
7. Age	46.41	14.02	—	−0.12^*	−0.03	0.10	−0.03	−0.05	0.07	—
8. Political Orientation	5.49	3.96	—	0.06	0.11^*	0.34^***	0.08	0.02	0.02	0.20^***	—

Note. Higher scores indicate greater justification of violence, conspiracy mentality, election fraud conspiracy beliefs, and political participation. Gender was coded 0 = female, 1 = male. Political orientation was coded such that higher scores reflect a more conservative orientation. All 372 participants completed each measure.

p < .05. **p < .01. ***p < .001.

Election Fraud Conspiracy Theories

To test whether participants’ election fraud conspiracy beliefs, their normative political participation, and the interaction between these two variables predicted their justification of violence, we conducted a general linear model in Jamovi through the GAMLj package (which automatically centers continuous variables). Conspiracy beliefs and political participation were entered as independent variables, justification of violence was entered as a dependent variable, and gender, age, education and political orientation were entered as control variables. The main effect of conspiracy beliefs on justification of violence was significant, F(1, 362) = 45.68, p < .001, η_p² = .11. This result supports Hypothesis 1. In addition, the main effect of normative political participation on justification of violence was also significant, indicating that increased political participation predicted a stronger justification of violence, F(1, 362) = 55.12, p < .001, η_p² = .13. More interesting was the finding that the interaction effect was significant, F(1, 362) = 12.43, p < .001, η_p² = .03. This provides preliminary support for Hypothesis 2: conspiracy theories may play a role in determining when political participation turns violent.

To further explore the interaction effect, we conducted simple slopes analyses. At low levels of political participation, the relationship between conspiracy beliefs and justification of violence was significant, F(1, 362) = 5.50, p = .020, η_p² = .02. At high levels of political participation, this effect was also significant, but with a larger effect size, F(1, 362) = 50.07, p < .001, η_p² = .12. Furthermore, at low levels of conspiracy beliefs, the relationship between political participation and justification of violence was significant, F(1, 362) = 6.73, p = .010, η_p² = .02. At high levels of conspiracy beliefs, this effect was also significant, but with a larger effect size F(1, 362) = 60.18, p < .001, η_p² = .14. These results indicate that participants were most likely to justify the violence during the Capitol Hill riots when they had high levels of both political participation and election fraud conspiracy beliefs. A visual presentation of the interaction can be seen in Figure 1.

Figure 1

The Effect of Political Participation on Justification of Violence for Mean Levels of Election Fraud Conspiracy Theory Beliefs (EFCT) ± 1 SD

Conspiracy Mentality

We then conducted a similar analysis with conspiracy mentality as an independent variable. The main effect of conspiracy mentality on justification of violence was significant, F(1, 362) = 25.91, p < .001, η_p² = .07. This finding supports Hypothesis 1. In addition, the main Effect of Political Participation on Justification of Violence was significant, F(1, 362) = 51.27, p < .001, η_p² = .12, as was the interaction, F(1, 362) = 13.01, p < .001, η_p² = .04.

We again conducted simple slopes analyses. At low levels of political participation, the link between conspiracy mentality and justification of violence was not significant, F(1, 362) = 0.19, p = .665, η_p² < .01. At high levels of political participation, this link was significant, F(1, 362) = 31.62, p < .001, η_p² = .08. Furthermore, at low levels of conspiracy mentality, the link between political participation and justification of violence was not significant, F(1, 362) = 2.89, p = .090, η_p² < .01. At high levels of conspiracy mentality, this link was significant, F(1, 362) = 56.54, p < .001, η_p² = .14. Consistent with the findings on election fraud conspiracy theories, justification of violence was highest among participants who scored high on both political participation and conspiracy mentality.

Discussion

Our findings from Study 1 supported Hypothesis 1: Conspiracy mentality and election fraud conspiracy theories predict justification of violence in the Capitol Hill riots among U.S. citizens who voted for Trump in 2020. More importantly, we found an interaction effect with political participation, indicating that participants justified violence most when they were high in both political participation and either conspiracy theory measure. As these results came from exploratory analyses, Study 2 provides a confirmatory test of the role of political participation in justification of the Capitol Hill riots.

Study 2

In Study 2, we experimentally varied whether participants who voted for Trump in 2020 were exposed to the conspiracy theory that the Democratic Party rigged the 2020 election, and tested its effects on justification of the Capitol Hill riots. In addition, we confirmatively tested the moderating role of political participation. Building on the findings from Study 1, we hypothesized that exposing individuals to conspiracy-affirming information regarding the 2020 U.S. presidential elections would lead to a greater justification of the violence used during this event compared to exposure to conspiracy-denying information (Hypothesis 1). In addition, we expected that the effects of the conspiracy exposure manipulation on justification of violence would be stronger among participants with relatively high levels of political participation (Hypothesis 2).

Method

Participants and Design

We recruited 799 U.S. participants through Prolific, prescreened to include only those who voted for Trump in the 2020 U.S. presidential election. However, 48 participants reported that they did not meet this criterion and were therefore excluded from further analyses. After excluding these participants, the study included 751 participants, 377 in the control condition and 374 in the experimental condition. This sample size provides 80% power to detect small effect sizes (d = 0.18, one-sided). The final sample consisted of 360 men, 389 women, and 2 “other,” with ages ranging from 19 to 95 years (M = 46.19, SD = 13.77).

Measures

We measured justification of violence, political participation, and election fraud conspiracy beliefs using the same items as in Study 1. A reliability analysis showed excellent internal consistency for each scale: α = .87 for justification of violence, α = .96 for political participation, and α = .95 for conspiracy beliefs. Demographics were also measured the same way as in Study 1 to serve as control variables.

Procedure

Participants provided their informed consent. Following this, participants completed the political participation measure. Then, participants read an internet article by an unknown Republican author (designed by the experimenters) about the 2020 U.S. presidential elections. In the conspiracy condition, participants read a text containing several arguments affirming the conspiracy theory that Joe Biden’s victory was attained through voter fraud. In the control condition, participants read a text containing several arguments denying the conspiracy theory that Joe Biden’s victory was attained through voter fraud. Both texts were roughly similar in terms of length and narrative structure; full texts are available in the Supplementary Materials. Participants then provided a brief summary of the article they read and answered a dichotomous question as a manipulation check, indicating whether the author believed the 2020 U.S. presidential election was rigged (yes or no).

Following the internet article, participants completed the conspiracy beliefs and justification of violence measures. After completing these, participants answered questions regarding basic demographic information. They were then provided with a debriefing that informed them of the manipulation and the purpose of the study. Finally, participants were redirected to a URL for payment.

Results

Manipulation Checks

A total of 93.0% of participants in the experimental condition, and 88.3% in the control condition, correctly interpreted whether or not the writer believed that the 2020 U.S. presidential election results were legitimate. In the following analyses, we report the results of the full sample. The results when excluding participants who failed the dichotomous manipulation check were similar, and in fact showed a stronger effect size for the interaction between the conspiracy exposure manipulation and political participation. These results are provided in the OSM.

Participants in the control condition reported lower election fraud conspiracy beliefs (M = 4.60, SD = 1.80) than participants in the experimental condition (M = 5.02, SD = 1.79), t(749) = −3.18, p = .002, Cohen’s d = 0.23. These results indicate that our manipulation was successful in varying conspiracy beliefs, although with a small effect size.

Moderation Analysis

We then tested that reading conspiracy-affirming, as opposed to conspiracy-denying, information increased justification of violence, and the interaction between the conspiracy manipulation and political participation. Gender, age, education, and political orientation were controlled for in the analysis. Using the general linear model method in Jamovi through the GAMLj package (which automatically centers continuous variables), the conspiracy manipulation was entered as the independent variable, justification of violence as the dependent variable, and political participation as the moderator.

This analysis revealed a non-significant main effect of the conspiracy manipulation, F(1, 738) = 0.07, p = .789, η_p² = .00. These results do not support our original hypothesis. However, the main effect of political participation was significant, F(1, 738) = 55.46, p < .001, η_p² = .07. More importantly, we found a significant interaction effect between the conspiracy manipulation and political participation, F(1, 738) = 3.99, p = .046, η_p² < .01. This relationship is depicted graphically in Figure 2. In addition, re-estimating the moderation model without any control variables yielded similar results, including a significant interaction between the conspiracy manipulation and political participation (see OSM for the analysis).

Figure 2

The Effect of Political Participation on Justification of Violence per Condition

To further explore the nature of the interaction effect, we conducted simple slopes analyses. The effect of conspiracy manipulation on justification of violence was non-significant at low levels of political participation, F(1, 738) = 2.55, p = .111, η_p² < .01; and at high levels of political participation, F(1, 738) = 1.50, p = .221, η_p² < .01. In the control condition, the association between political participation and justification of violence was significant, F(1, 738) = 16.50, p < .001, η_p² = .02. In the experimental condition, this association was also significant but with a bigger effect size, F(1, 738) = 47.40, p < .001, η_p² = .06. While no simple main effects of the conspiracy exposure manipulation at different levels of political participation emerged, these findings indicate that political participation was more strongly associated with justification of violence after participants were exposed to conspiracy theories.

Discussion

The results in Study 2 do not support the hypothesis that exposure to conspiracy-affirming information would have a main effect by increasing justification of violence in the Capitol Hill riots. Apparently, Trump supporters’ perceptions of the Capitol Hill riots overall are not easily influenced by a brief, experimenter-created blog post about this event. However, we did observe a significant interaction between the conspiracy manipulation and political participation on justification of violence, indicating that political participation positively predicts justification of violence, especially when participants were exposed to conspiracy theories.

General Discussion

This study aimed to illuminate how the conspiracy theory that the 2020 U.S. presidential elections were rigged motivated violent protesters to storm the Capitol in an attempt to reverse the election outcome (Ntontis et al., 2023). Study 1 suggested that political participation interacts with conspiracy theories to predict a tendency to justify political violence. Study 2 expanded on these findings and found that political participation predicts justification of violence, particularly if participants had been exposed to an election fraud conspiracy theory. Altogether, these findings suggest that conspiracy theories, particularly when aligned with pre-existing political beliefs, are important in understanding when political participation is associated with a tendency to justify political violence.

The present research expands scientists’ understanding of how political participation contributes to political violence. In addition, it sheds further light on the complex relationship between conspiracy theories and political participation within the specific context of the Capitol Hill riots. Connecting these findings to earlier research on these issues (e.g., Imhoff et al., 2021), conspiracy theories may be a key factor to predict when highly politically active individuals transition from engaging in normative political actions to nonnormative political actions. This would be consistent with earlier findings (e.g., van Prooijen, 2024; Wood, 2016), suggesting that conspiracy theories can drive individuals to view the system and elites as corrupt and threatening, justifying extreme or even violent measures. Presumably, politically active individuals are inherently motivated to change the status quo (Papaioannou et al., 2024), and conspiracy theories may intensify their beliefs that violence is necessary to achieve this goal.

Future research may examine how the combination of political participation and conspiracy theories affects society in other ways; for instance, particularly politically active people might play a key role in the spread of conspiracy theories online (e.g., “superspreaders”; van der Linden, 2022). Furthermore, the present findings might suggest that conspiracy theories are more likely to incite violence when promoted by politicians at political rallies, such as when Trump gave his speech prior to the Capitol Hill riots. Attending such a rally is an expression of being politically active, and as the politician amplifies conspiracy theories, the public may increasingly be motivated to take violent action. The sense of corruption and danger that conspiracy theories enhance may push politically active individuals to take more extreme measures.

Through its specific focus on the 2021 Capitol Hill riots, the present findings illuminate the role of conspiracy theories in undermining democracy. Although the argument that conspiracy theories undermine democracy—and increase support for autocratic forms of governance—is not a new insight (e.g., Mari et al., 2022; Papaioannou et al., 2024), previous studies have mostly focused on the direct effects that conspiracy theories have on factors predicting democratic (in)stability. This study deepens our understanding by examining which citizens are particularly likely to translate conspiracy theories into actions that undermine democracy. Future research should build on this understanding by investigating if political participation is also associated with other democratic threats, such as radicalization, and other instances of nonnormative political action not investigated here (e.g., spreading online hatred). Understanding why and when conspiracy theories predict democratic threats is crucial for developing prevention strategies and policies that safeguard citizens’ voting rights and democratic engagement.

Strengths and Limitations

A strength of this research is that both studies were preregistered and sufficiently powered. Furthermore, this study combined exploratory research (Study 1) with a confirmatory follow-up study (Study 2) and found consistent results. Moreover, the 2021 Capitol Hill riots were an impactful event that sparked discussion about the stability of democratic institutions globally. As such, understanding the possible causes of this event has both scientific and societal value. Altogether, the findings presented here paint a reliable picture of how political participation and conspiracy beliefs jointly help explain the 2021 Capitol Hill riots.

The fact that this research was context-specific to the Capitol Hill riots, the 2021 election fraud conspiracy theory, and Trump voters also suggests a limitation, however. The current studies do not allow for assessing how generalizable the results are to other cases of political violence. For instance, it is uncertain whether the same effect of political participation would emerge in the context of the 2023 Brazilian election riots. Although these riots shared many similarities with the Capitol Hill riots—such as far-right Bolsonaro supporters storming government buildings, likely connected with conspiracy theories alleging election fraud—there were also differences, for instance, in the cultural and legal context. More generally, it is of paramount importance to understand the causes of violent protests, uprisings, and societal unrest. In addition, our conclusions are limited to contingent political participation within an ideologically aligned group, as our sample only included Trump voters. This boundary condition was chosen to ensure ideological congruency between participants and the Capitol Hill rioters, thus increasing conceptual rigor but limiting generalizability. To draw more generalizable conclusions about how political participation and conspiracy theories interact to predict political violence, future research should examine whether similar patterns emerge in other ideological and cultural contexts, particularly in countries that vary in the degree of how democratic they are.

Another set of limitations pertains to features of our research design. First, our reframing of the theoretical model (from political participation as a moderator to conspiracy theories as a moderator) was not preregistered. Second, it proved difficult to manipulate election fraud conspiracy beliefs, as evident from the relatively weak effect size on our manipulation check. Presumably, most of our Trump-voting participants already held stable beliefs about whether the elections were rigged, making it difficult to experimentally manipulate such beliefs. Relatedly, we did not manipulate political participation in our study because doing so may be difficult, if not impossible. The current data, hence, do not allow for causal conclusions. In addition, we examined the justification of violence instead of actual violent behavior. While belief in conspiracy theories positively predicts aggressive behavior in experimental studies (Poon et al., 2023), we chose to measure justification of violence given the specific setting of the Capitol Hill riots, yielding significant methodological and ethical challenges to accurately measure violent behavior. Finally, we measured political participation and justification of violence within a specific context, rather than measuring normative and nonnormative political activity more broadly (e.g., Imhoff et al., 2021). This is because we aimed to examine our line of reasoning in the context of a prominent real-world example in the form of the Capitol Hill Riots. Future research could consider using more generic measures to further illuminate when normative political activity turns nonnormative.

Concluding Remarks

Political participation is a hallmark of democracy. Indeed, citizens’ right to protest and publicly disagree with powerholders constitutes an important difference between democratic and autocratic forms of governance. Paradoxically, however, some specific forms of political participation may violate democratic principles. The 2021 Capitol Hill riots were a monumental event in recent history that has underscored how fragile democratic institutions may be in a polarizing political climate. The present studies suggest that conspiracy theories are an important factor in understanding and predicting when political participation can turn into political violence. This study hence provides insights into why and when conspiracy theories contribute to political violence. We conclude that political participation predicts increased justification of political violence, but particularly among people who also believe in ideologically-congruent conspiracy theories whose content reinforces anti-democratic beliefs.

Supplemental Material

sj-docx-1-spp-10.1177_19485506261421177 – Supplemental material for The Roles of Conspiracy Theories and Political Participation on Justifying Violence in the Capitol Hill Riots

Supplemental material, sj-docx-1-spp-10.1177_19485506261421177 for The Roles of Conspiracy Theories and Political Participation on Justifying Violence in the Capitol Hill Riots by Jesse Koster, Fengyu Dou, Naomi Dol, Yuan Ning and Jan-Willem van Prooijen in Social Psychological and Personality Science

Footnotes

Handling Editor: Christian Unkelbach

ORCID iDs

Jesse Koster

Naomi Dol

Yuan Ning

Jan-Willem van Prooijen

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Supplemental Material

Supplemental material is available in the online version of the article.

Notes

Author Biographies

Jesse Koster is a PhD candidate at the Vrije Universiteit Amsterdam. He initially participated in this research project for course credit for his Research Master in Social Psychology but continued working on the manuscript as the main author. His research focuses on psychological processes underlying social issues such as political violence, agression towards frontline workers, and social cohesion in times of crises.

Fengyu Dou, Naomi Dol, and Yuan Ning were all Research Master Students in Social Psychology at VU Amsterdam. They participated in this research project as part of course requirements

Jan-Willem van Prooijen is Associate Professor of Psychology at VU Amsterdam, Senior Researcher at the Netherlands Institute for the Study of Crime and Law Enforcement (NSCR), and Endowed Professor of Radicalization, Extremism, and Conspiracy Thinking at Maastricht University.

References

Armaly

M. T.

Buckley

D. T.

Enders

A. M.

(2022). Christian nationalism and political violence: Victimhood, racial identity, conspiracy, and support for the Capitol attacks. Political Behavior, 44(2), 937–960. https://doi.org/10.1007/s11109-021-09758-y

Biesecker

Kunzelman

Flaccus

Mustian

(2021, January 11). Records show fervent Trump fans fueled US Capitol takeover. AP News. https://apnews.com/article/us-capitol-trump-supporters-1806ea8dc15a2c04f2a68acd6b55cace

Brannen

S. J.

Haig

C. S.

Schmidt

(2020, March 2). The age of mass protests: Understanding an escalating global trend. Center for Strategic and International Studies. https://www.csis.org/analysis/age-mass-protests-understanding-escalating-global-trend

Bruder

Haffke

Neave

Nouripanah

Imhoff

(2013). Measuring individual differences in generic beliefs in conspiracy theories across cultures: Conspiracy mentality questionnaire. Frontiers in Psychology, 4, 225. https://doi.org/10.3389/fpsyg.2013.00225

Das

Morey

B. N.

Bruckner

T. A.

(2023). Mental health symptoms following the January 6th attack on the United States Capitol. Social Science & Medicine, 330, 116015. https://doi.org/10.1016/j.socscimed.2023.116015

Diethelm

McKee

(2009). Denialism: What is it and how should scientists respond? The European Journal of Public Health, 19(1), 2–4. https://doi.org/10.1093/eurpub/ckn139

Douglas

K. M.

Sutton

R. M.

(2023). What are conspiracy theories? A definitional approach to their correlates, consequences, and communication. Annual Review of Psychology, 74, 271–298. https://doi.org/10.1146/annurev-psych-032420-031329

Enders

Klofstad

Uscinski

(2024). The relationship between conspiracy theories and violence. Harvard Kennedy School (HKS). Misinformation Review, 5(6). https://doi.org/10.37016/mr-2020-163

Gil de Zúñiga

Jung

Valenzuela

(2012). Social media use for news and individuals’ social capital, civic engagement, and political participation. Journal of Computer-Mediated Communication, 17(3), 319–336. https://doi.org/10.1111/j.1083-6101.2012.01574.x

10.

Imhoff

Bruder

(2014). Speaking (un-)truth to power: Conspiracy mentality as a generalized political attitude. European Journal of Personality, 28(1), 25–43. https://doi.org/10.1002/per.1930

11.

Imhoff

Dieterle

Lamberty

(2021). Resolving the puzzle of conspiracy worldview and political activism: Belief in secret plots decreases normative but increases nonnormative political engagement. Social Psychological and Personality Science, 12(1), 71–79. https://doi.org/10.1177/1948550619896491

12.

Jiang

(2023). The impact of political ideology, knowledge and participation on electoral conspiracy endorsement. Frontiers in Political Science, 5, 1069468. https://doi.org/10.3389/fpos.2023.1069468

13.

Jolley

Douglas

K. M.

(2014). The social consequences of conspiracism: Exposure to conspiracy theories decreases intentions to engage in politics and to reduce one’s carbon footprint. British Journal of Psychology, 105(1), 35–36. https://doi.org/10.1111/bjop.12018

14.

Jolley

Douglas

K. M.

Leite

A. C.

Schrader

(2019). Belief in conspiracy theories and intentions to engage in everyday crime. British Journal of Psychology, 58(3), 534–549. https://doi.org/10.1111/bjso.12311

15.

Jolley

Paterson

J. L.

(2020). Pylons ablaze: Examining the role of 5G COVID-19 conspiracy beliefs and support for violence. British Journal of Psychology, 58(3), 628–640. https://doi.org/10.1111/bjso.12394

16.

Klofstad

Christley

Diekman

Enders

Funchion

Hemm

Kübler

Littrell

Murthi

Premaratne

Seelig

Verdear

Wuchty

Uscinski

J. E.

(2025). The new Satanic panic. Political Science Quarterly, 140(2), 249–268. https://doi.org/10.1093/psquar/qqae081

17.

Lonsdorf

Dorning

Isackson

Kelly

M. L.

Chang

(2022, January 5). A timeline of how the Jan. 6 attack unfolded. including who said what and when. NPR. https://www.npr.org/2022/01/05/1069977469/a-timeline-of-how-the-jan-6-attack-unfolded-including-who-said-what-and-when

18.

Mari

Gil

Zúñiga

Suerdem

Hanke

Brown

Vilar

Boer

Bilewicz

(2022). Conspiracy theories and institutional trust: Examining the role of uncertainty avoidance and active social media use. Political Psychology, 43(2), 277–296. https://doi.org/10.1111/pops.12754

19.

Miller

M. K.

(Ed.). (2023). The social science of QAnon: A new social and political phenomenon. Cambridge University Press. https://doi.org/10.1017/9781009052061.

20.

Ntontis

Jurstakova

Neville

Haslam

S. A.

Reicher

(2023). A warrant for violence? An analysis of Donald Trump’s speech before the US Capitol attack. British Journal of Social Psychology, 63(1), 3–19. https://doi.org/10.1111/bjso.12679

21.

Obaidi

Kunst

Ozer

Kimel

S. Y.

(2022). The “Great Replacement” conspiracy: How the perceived ousting of whites can evoke violent extremism and Islamophobia. Group Processes & Intergroup Relations, 25(7), 1675–1695. https://doi.org/10.1177/13684302211028293

22.

Papaioannou

Pantazi

Van Prooijen

J.-W.

(2024). Rejection of the status quo: Conspiracy theories and preference for alternative political systems. British Journal of Social Psychology, 63(4), 2077–2099. https://doi.org/10.1111/bjso.12754

23.

Poon

K.-T.

Chan

R. S. W.

Lai

H.-S.

(2023). Are rules made to be broken? Conspiracy exposure promotes aggressive behavior. Political Psychology, 45(6), 923–940. https://doi.org/10.1111/pops.12947

24.

Rottweiler

Gill

(2020). Conspiracy beliefs and violent extremist intentions: The contingent effects of self-efficacy, self-control, and law-related morality. Terrorism and Political Violence, 34(7), 1485–1504. https://doi.org/10.1080/09546553.2020.1803288

25.

Šrol

Čavojová

Mikušková

E. B.

(2022). Finding someone to blame: The link between COVID-19 conspiracy beliefs, prejudice, support for violence, and other negative social outcomes. Frontiers in Psychology, 12, 726076. https://doi.org/10.3389/fpsyg.2021.726076

26.

van der Linden

. (2022). Misinformation: Susceptibility, spread, and interventions to immunize the public. Nature Medicine, 28, 460–467. https://doi.org/10.1038/s41591-022-01713-6

27.

van Prooijen

J.-W.

(2024). Group-oriented motivations underlying conspiracy theories. Group Processes & Intergroup Relations, 27(5), 1050–1067. https://doi.org/10.1177/13684302241240696

28.

van Prooijen

J.-W.

van Vugt

(2018). Conspiracy theories: Evolved functions and psychological mechanisms. Perspectives on Psychological Science, 13(6), 770–788. https://doi.org/10.1177/1745691618774270

29.

Uscinski

J. E.

Enders

A. M.

Seelig

M. I.

Klofstad

C. A.

Funchion

J. R.

Everett

Wuchty

Premaratne

Murthi

M. N.

(2021). American politics in two dimensions: Partisan and ideological identities versus anti-establishment orientations. American Journal of Political Science, 65(4), 877–895. https://doi.org/10.1111/ajps.12616

30.

Vegetti

Littvay

(2022). Belief in conspiracy theories and attitudes toward political violence. Italian Political Science Review, 52(1), 18–32. https://doi.org/10.1017/ipo.2021.17

31.

Wang

van Prooijen

J.-W.

(2023). Stolen elections: How conspiracy beliefs during the 2020 American presidential elections changed over time. Applied Cognitive Psychology, 37(2), 277–289. https://doi.org/10.1002/acp.3996

32.

Wood

M. J.

(2016). Conspiracy suspicions as a proxy for beliefs in conspiracy theories: Implications for theory and measurement. British Journal of Psychology, 108(3), 507–527. https://doi.org/10.1111/bjop.12231

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