New study reveals how political bias conditions the impact of conspiracy thinking

A recent study published in Political Psychology suggests that a person’s general tendency to believe in conspiracies strongly predicts their endorsement of specific political rumors, but mostly when those rumors attack their political rivals. The research provides evidence that psychological traits and political loyalties work together to shape what people are willing to believe. These findings help explain how political divisions feed into the spread of misinformation.

Previous work has identified two separate predictors of these beliefs. First, people have varying levels of “conspiracy thinking,” which is a general psychological tendency to assume that secret, sinister forces control world events.

Second, people tend to favor their own political groups. They usually accept theories that blame their political rivals and reject theories that accuse their own side. The researchers designed this study to see if these two separate factors actually interact with one another.

The scientists suspected that general conspiracy thinking might have a stronger effect when a rumor aligns with a person’s political bias. People naturally want to protect the reputation of their own group while assuming the worst about their opponents. Because of this natural bias, the researchers expected that people who are highly prone to conspiratorial thinking would eagerly accept rumors about their rivals.

“I am a political scientist who is interested in conspiracy theories, mainly partisan conspiracy theories involving parties/politicians/ideological groups,” said study author Omer Yair, a research Fellow at the Institute for Liberty and Responsibility at the Lauder School of Government, Diplomacy and Strategy at Reichman University.

“And over the last few years I have read many articles showing that both political preferences, such as party identification, and “conspiracy thinking” (AKA conspiracy mentality), i.e., people’s tendency to believe in conspiracy theories, independently explain belief in partisan conspiracy theories.

“I was wondering whether a combination, i.e., an interaction, of these two important predictors of belief in conspiracy theories, would help better explain who the people most likely to believe in these partisan conspiracy theories are. A short search in the literature found no empirical support for such an interaction, so we gathered data from several surveys and found consistent support for our interaction hypothesis.”

To investigate this, the scientists analyzed survey data from six different studies. Two of these studies took place in the United States, and four took place in Israel. In total, the combined sample included 10,765 adult participants.

The surveys asked participants about 61 different conspiracy theories. Thirty of these theories were political in nature, meaning they accused specific political figures or parties of secret plots. The other 31 theories were non-political, such as rumors about hidden information regarding aliens or secret cures for diseases.

The first United States survey included 2,021 adults and was conducted in the spring of 2021. It asked participants about 12 political theories and 27 non-political theories. The sample was designed to be representative of the American adult population in terms of age, gender, race, and income.

The political items featured rumors such as the idea that Republicans stole previous presidential elections or that Barack Obama faked his citizenship to become president. The non-political items covered ideas that did not target a specific political party. These included rumors that an elite one percent controls the economy or that the dangers of genetically modified foods are being kept secret from the public.

The second United States survey included 2,765 adults and was conducted in July 2024. This survey focused specifically on two political theories regarding the recent assassination attempt on presidential candidate Donald Trump.

In Israel, the four original surveys included a combined 5,979 adults and were conducted between February 2023 and April 2025. These surveys asked participants about 16 political theories and four non-political theories.

The Israeli theories focused on the political rivalry between supporters of Prime Minister Benjamin Netanyahu and supporters of the opposing political group. For example, one theory suggested that security officials intentionally hid information about the October 7 Hamas attacks from the Prime Minister.

In all six studies, the scientists measured participants’ general conspiracy thinking using a standard four-question scale. Participants rated their agreement with statements suggesting that unknown people secretly control the country or that major events are the result of hidden plots.

The researchers also measured how strongly participants believed specific theories. They pooled the responses together to test the statistical relationship between a person’s general conspiratorial mindset, their political identity, and their belief in specific rumors.

The researchers found that general conspiracy thinking strongly predicts belief in political conspiracy theories, but this relationship depends heavily on political alignment. When a theory accused a person’s political rivals of wrongdoing, their underlying tendency to believe in conspiracies strongly activated. In these situations, highly conspiratorial individuals were very likely to believe the rumor.

When a theory accused a person’s own political group of a secret plot, the effect of conspiracy thinking was much weaker. Even people with a high tendency to believe in hidden plots were much less likely to believe a rumor if it made their own side look bad.

The researchers noted that the strongest interaction occurred during the 2024 United States election, a time when political tensions were especially high.

“Our results show an interesting combination or marriage of psychological predispositions and political preferences. That is, it’s not just people’s politics or just people’s psychological tendencies that affect their endorsement of partisan conspiracy theories – it’s a combination,” Yair told PsyPost.

“I think that the most extreme example we have in our data concerns the belief in a conspiracy theory according to which Democratic operatives were behind the assassination attempt against Donald Trump in July 2024 in Pennsylvania. Based on our analysis, less than 10 percent of Republicans with the lowest levels of conspiracism in the data endorsed this conspiracy theory, while almost 80 percent of Republicans with the highest levels of conspiracism endorsed it.”

The scientists also found that this interaction only applies to political rumors. When looking at non-political theories, like hidden information about unidentified flying objects or genetically modified foods, political affiliation did not change the impact of conspiracy thinking. A highly conspiratorial Republican and a highly conspiratorial Democrat were equally likely to believe these neutral rumors.

The data also revealed some geographic differences between the two countries. “We had data from both the United States and Israel, and I was a bit surprised to find the specific differences we had between the two countries,” Yair said. “We found that the effect of conspiracy thinking on conspiracy beliefs was consistently stronger in the United States, while the conspiracy theories in Israel were more ‘politicized’ in the sense that the baseline partisan differences (i.e., among partisans, from the rival groups, who had the lowest levels of conspiracy thinking) were consistently stronger in Israel. As an Israeli, it was quite surprising.”

“I think there are two main takeaways: First, even people who are ‘conspiratorial’ and tend to believe in many conspiracy theories will likely not react similarly to conspiracy theories that accuse their political rival and conspiracy theories that accuse their own political group. Rather, they are likely to believe in conspiracy theories that accuse the opposition more than conspiracy theories that accuse their political in-group.”

“Second, not all members of a partisan/ideological group are likely to believe in conspiracy theories that accuse their political rivals,” Yair explained. “Rather, group members who are ‘conspiratorial’ and tend to believe in those conspiracy theories are most likely to believe such conspiracy theories; other group members – less or even much less.”

While the research provides evidence for this psychological and political interaction, the scientists noted a few limitations. The data comes from only two countries, so it is possible that these patterns might look different in other parts of the world.

Additionally, the observational nature of the surveys means researchers cannot completely rule out reverse causality. It is possible that believing in specific rumors might cause a person’s general conspiracy thinking to increase, though the researchers view this as unlikely.

The boundary between political and non-political theories can also be blurry. A rumor that seems totally unconnected to politics today might become deeply tied to a specific political party tomorrow, making it difficult to categorize these beliefs perfectly.

Future research, Yair said, could test these ideas in other social contexts, such as group conflicts based on race, gender, or nationality. Experimental studies that alter how a rumor is presented could also help confirm these findings.

The study, “Conspiracy thinking and belief in partisan conspiracy theories: A moderating effect of partisan congruence?“, was authored by Omer Yair, Shira Hebel-Sela, Amnon Cavari, and Asif Efrat.