Guest Lecture by Brian O'Shea

1 May 2025, by Jessica Schröter

On 23.06.2025 (14:15-15:45, Von-Melle-Park 5, R3016) Dr. Brian O'Shea (University of Nottingham) will give a lecture on "The impact of regional infectious disease prevalence on pre-political beliefs, partisan preference and intergroup tensions." as part of the research colloquium.

Abstract: Tybur et al., (2016) suggested that the relationship between pathogens and politics reflects intragroup rather than intergroup motivations. This contrast was based on their report from a survey of 11,501 participants across 30 countries that cross-national pathogen stress related to traditional group norm adherence (intragroup), but was unrelated to the endorsement of intergroup hierarchy, as measured by social dominance orientation (SDO). This null effect was particularly surprising given the array of prior evidence showing that environments with more infectious diseases and experimental reminders of diseases increase intergroup conflict/prejudice. However, the authors did not control for group status, as indexed for instance by race/ethnicity, although decades of prior research demonstrate that both the levels and effects of SDO are fundamentally moderated by group status (e.g., Sidanius et al., 2001, Kunst et al., 2017). Ignoring these behavioral asymmetries thus may mask true effects. Here we show that parasite stress is related to SDO across 48 countries (N > 500,000), but only after controlling for dominant versus subordinate group status. We replicate this effect across the 50 US states (N > 350,000) with White versus Black participants. These distinct race divergences extend to US political preferences such that Whites are explicitly and implicitly more likely to prefer Republicans in high infectious disease states, while non-Whites instead prefer Democrats. Therefore, racial groups express more support in threatening environments for beliefs andpolitical groups that are perceived as likely to protect or help their group interests. Additionally, I will show how new variants of the Germ Aversion (GA) subscale I developed, which captures ingroup (local region) versus outgroup (developing country) GA tendencies can enhance our understanding of explicit (e.g., likelihood of being infected versus healthy, levels of warmth; N > 1,472) and implicit (Brief Implicit Association Test; N = 456 – 1,332) attitudes towards ingroup (US) and outgroups (China, Italy, UK) during COVID-19. While controlling for key variables (e.g., COVID-19 concern), higher outgroup, but not ingroup or general germ aversion, was the most consistent predictor of ingroup preferences and outgroup disdain, with political ideology being the key mediator. Specifying the targets of germ aversion biases enhances our understanding of intergroup relations during a pandemic.