This project explores the psychology of antisemitic misinformation. Antisemitism manifests in conspiracy theories and misinformed beliefs about Jews across the political spectrum, including conspiracy theories of a secret and subversive Jewish domination (more typically on the right) and the blaming of all (or a majority of) Jews for Israeli government policies on the left. The project will apply the Gateway Belief Model (GBM) and inoculation theory to this type of misinformation. GBM suggests that people's beliefs are influenced by the degree to which they perceive there to be a consensus among experts on an issue - e.g., the scientific consensus that human activities are the primary cause for global warming currently. Inoculation theory proposes that preemptive exposure to weak arguments used to propagate misinformation strengthens resistance to misinformation, akin to a vaccine. While both these theories have shown promise in combating misinformation in other areas, they have not yet been applied to a prejudice such as antisemitism. Experiments will be conducted in which a method called Reverse Gateway Belief Model (R-GBM), which presents false consensus messaging (e.g. "95% of historians agree that Jews have historically exercised significant control over European politics), will be used on participants to help identify the type of misinformation that leads to antisemitic attitudes. This will be done by assessing its impact on participants' scores on validated scales for measuring different types of antisemitism. In other experimental groups, inoculation messaging will be used, involving a preemptive exposure to weak argumentation for antisemitic ideas. I hypothesise that R-GBM exposure will increase scores on these scales, while inoculation messages will decrease them. Political ideology will be measured and included as a factor that potentially mediates the impact of the R-GBM and Inoculation on levels of antisemitism. For example, given the above-mentioned distinctions in the types of antisemitism more prevalent across the political spectrum, I expect that inoculating against Israel-related antisemitism will have a bigger impact on individuals identifying themselves as more left-wing, while inoculating against notions of Jewish domination may have a stronger impact on right-wing individuals. Another potential mediating factor I will assess is competitive victimhood, which refers to a tendency to believe one's own group has suffered more than an outgroup. This has been found to fuel antisemitism among minorities, e.g. through the belief that an emphasis on the Holocaust prevents a recognition of other historical cases of oppression. To test this, the study will sample minority groups and measure their sense of their group's victimhood using established measures. Using R-GBM and inoculation again, one experimental group will be presented with R-GBM messaging including such as "Historians unanimously agree that, despite the disproportionate focus on the Holocaust, Jews have not suffered much in history relative to other groups", while an inoculation condition may pair a weak version of this argument with an example of Jewish participation in the civil rights movements of other historically persecuted groups. The hypothesis is that those with high levels of competitive victimhood will show increased antisemitism following R-GBM exposure and decreased antisemitism following inoculation. Overall, this project aims to pair the existing work on misinformation with that on the psychology of antisemitism, using GBM and inoculation theory to better understand antisemitic misinformation and its psychological determinants. This could offer potential practical interventions that better target the misinformation underlying antisemitism, and may enhance our understanding of the interplay between the psychological processes affecting both misinformation belief and prejudice (in this case against Jews).