“…In an early demonstration of the impact of social relationships on disgust, Case et al (2006) found evidence across two studies that people are less disgusted by the smell of, and by changing, their own children's nappies compared to those of other children. Relatedly, experimental and questionnaire-based research indicates that people feel more comfortable being close to, and in a shared environment with, ingroup (rather than outgroup) members (Novelli, Drury, & Reicher, 2010;Steffens, Slade, Stevens, Haslam, & Rees, 2019). These findings align with the evolutionary perspective that we are 'hard-wired' to avoid, or at least be more cautious of, outgroup members because they are more likely to carry pathogens that we (ingroup members) are not immune to (e.g., see Faulkner, Schaller, Park, & Duncan, 2004).…”