Body odour disgust sensitivity is associated with xenophobia: evidence from nine countries across five continents

Body odour disgust sensitivity is associated with xenophobia: evidence from nine countries across five continents.Marta Z. Zakrzewska et al. Royal Society Open Science, April 12 2023. https://doi.org/10.1098/rsos.221407

Abstract: Body odour disgust sensitivity (BODS) reflects a behavioural disposition to avoid pathogens, and it may also involve social attitudes. Among participants in the USA, high levels of BODS were associated with stronger xenophobia towards a fictitious refugee group. To test the generalizability of this finding, we analysed data from nine countries across five continents (N = 6836). Using structural equation modelling, we found support for our pre-registered hypotheses: higher BODS levels were associated with more xenophobic attitudes; this relationship was partially explained by perceived dissimilarities of the refugees' norms regarding hygiene and food preparation, and general attitudes toward immigration. Our results support a theoretical notion of how pathogen avoidance is associated with social attitudes: ‘traditional norms’ often involve behaviours that limit inter-group contact, social mobility and situations that might lead to pathogen exposure. Our results also indicate that the positive relationship between BODS and xenophobia is robust across cultures.

4. Discussion

Understanding the link between disease detection/avoidance and xenophobia is critical for understanding the psychology of inter-group processes. Here, we focus on BODS, a potent sensory disease avoidance function, and how it is associated with xenophobic attitudes. Specifically, the present research used a large sample and a pre-registered set of hypotheses to extend previous findings of a positive relationship between BODS and explicit xenophobia [16] across countries and continents. Of particular interest was to understand whether or not body odour disgust is linked to negative attitudes to refugees because of the perceived dissimilarity of the refugees. We found that this was the case, and that our findings generalized well across most countries.

Most importantly, we show that how strongly people report to be disgusted by body odours is related to negative attitudes towards a fictitious refugee group (i.e. effect of BODS on xenophobia) and our overall effect size was very similar to previous findings in participants from the USA [16]. In the current study, data were analysed from nine culturally different and large samples in Africa, North America, South America, Europe, Asia and Oceania. The observed result was partially explained by how respondents perceived the refugee group as different in terms of food, hygiene and sanitary practices, and general attitudes towards immigration. This is in line with the disease avoidance theory that aims to explain suggesting that social behaviours and attitudes are connected to avoiding pathogens. Importantly, our results indicate that the relationship between BODS and xenophobia generalizes across populations, and can be partially explained by perceived outgroup norms. Our results thus provide support for the traditional norms account [2,4,19]. Hence, rather than geographical or genetic difference, perceived similarity in food preparation practices seems to be a driver of xenophobic attitudes, and it partially mediates the relationship between other key elements of disease avoidance (i.e. BODS) and xenophobia.

We extended previous findings by comparing attitudes towards the unfamiliar fictitious group from EA to attitudes towards a potentially more similar (at least for western cultures) fictitious outgroup coming from EE. Indeed, the EA Drashneans were consistently rated by most respondents as more dissimilar compared with the EE Drashneans; with the exception of Kenya, which is located in Eastern Africa. This manipulation potentially allows for better causal inferences, even if it worked on the intermediate variable only (perceived dissimilarity) and not the outcome (xenophobia); the difference in perception did not translate to higher levels of xenophobia for the EA Drashneans. This result is at odds with our hypothesis as we expected that the unfamiliar group would be both perceived as more different and elicit more negative attitudes (hypothesis 8 in Secondary hypotheses). However, even though EA Drashneans were perceived as more dissimilar, both groups were generally rated as being quite dissimilar, which might explain the lack of differences in the attitudes towards the two groups. Hence, while perceived group similarity is important in understanding the link between BODS and social attitudes, understanding the underlying mechanisms by which dissimilarity operates in these processes needs further exploration.

One limitation of the current study is that it is cross-sectional, comparing attitudes of individuals at one point in time. Exploring changing attitudes in a longitudinal perspective would add important knowledge on how the disgust/xenophobia relation evolves. As with most behavioural research, our study is also vulnerable to sample bias. For example, our study might have over-sampled from the more educated portions within the populations of reference. This might have an impact on the overall levels of xenophobia, since education typically is associated with lower levels of prejudice [35]. Similarily, our sample might be selective in terms of personality factors (e.g. openness to experience), which are also known to relate to prejudice (e.g. [36,37]). However, given the strengths of our study (e.g. the size and demographic stratification of the sample) in combination with the fact that results generalized well across nine countries, we are confident in the generalizability of our findings in a global context.

Our study points to several new lines of investigations relevant for future research in the field. Although explored only superficially in this study, there seems to be certain variability in the strength of the relationship between BODS and social attitudes. The effect was largest in Canada, and several other Western, English-speaking countries, but it was absent in Kenya—one East African country in our study. Such variability is not unexpected, as recent multi-country studies show variation even in highly robust findings [38]. It would be interesting to see if this variability is related to specific geographical, cultural or pandemic-related factors. Given the heterogeneity of our surveyed countries, however, such enquiries are outside the scope of the present study. An interesting topic to explore more with regard to pathogens and social interactions would be to see how disease avoidance affects other, less explored senses such as taste and touch. In fact, a recent study suggests that disease history might be related to affective touch diversity towards a close one [39]. Another important area of future research pertains to how individual differences related to disease avoidance mechanisms translate into behaviours during heightened risk of contamination, such as the COVID-19 pandemics. For example, it is unclear whether the COVID-19 pandemic has increased general levels of xenophobia [40]. However, what the current study shows is that the relationship between levels of BODS and xenophobia is similar to relations observed in an earlier, pre-pandemic study. This could suggest that a salient pathogen threat does not necessarily dramatically affect relations between disgust and attitudes towards fictitious outgroups of varying similarity.