Fri. Mar 24th, 2023
Scanning electron micrograph of a pair of Schistosoma mansoni.  They live in your blood!
Enlarge / Scanning electron micrograph of a pair of Schistosoma mansoni. They live in your blood!

A number of studies have shown that political and personal beliefs may be related to health behaviors. For example, political orientation can be influenced by a person’s beliefs about community, self-reliance, and morality, and the same beliefs can affect that person’s likelihood of seeking treatment for a potentially stigmatizing condition, such as a mental or sexual health issue. A recent article published in PNAS builds on past findings and suggests that individual traditionalism is linked to national parasitic stress.

The study recruited participants from 30 countries, with at least 200 people per country. These participants completed a short questionnaire describing their attitudes towards political issues and groups of people.

This questionnaire was designed to gauge participants’ attitudes toward three things: traditionalism, social dominance, and sensitivity to feelings of disgust. Traditionalism was judged in terms of adherence to old-fashioned values, family orientation, and religiosity. Social dominance orientation was assessed in terms of how much participants preferred equality between groups. Finally, disgust sensitivity was assessed in terms of reactions to different situations, such as ‘stepping on dog shit’.

The authors then aggregated these responses at the individual level and examined their relationship to parasitic stress, which was defined by estimates of the historical prevalence of parasites within national populations.

The most striking part of the study’s results showed that individuals in countries with higher parasitic stress were more traditional. This relationship was highly correlated (r=0.70, p<0.001), but of course this does not prove a causal relationship between parasite prevalence and traditionalism. The authors found no significant relationship between parasitic stress and social dominance orientation (i.e. beliefs about intergroup equality), nor did they discover an association between disgust sensitivity and parasitic stress. The latter might have made sense, since strong feelings of disgust could help people avoid situations where they're more likely to pick up parasites.

Based on these results, the authors suggest that people who are particularly motivated to avoid pathogens may also find traditional rules and rituals attractive. For example, people who are particularly averse to contracting sexually transmitted diseases may be more inclined to adhere to more traditional values ​​regarding sexual behavior. While not a direct link, it is possible that pathogen aversion may have influenced the development of traditional value systems.

In addition, traditional food preparation techniques typically contain ingredients with antimicrobial properties, and traditional hygiene rules regarding handing over food tend to limit exposure to pathogens. People who follow these traditions are more likely to influence the eating behavior of others, so that this behavior spreads and exposure to pathogens is significantly reduced.

As these two examples show, the relationship between pathogen avoidance and traditional values ​​suggested in this study may reflect either an individual’s motivation to regulate their own exposure to pathogens or an individual’s influence on the behavior of reflect others.

At present, any causal links between traditionalism, exposure to pathogens, aversion to pathogens and parasitic stress are unclear. Future research in this area may reveal which of these came first: pathogen aversion, traditional values, or problems with high infection rates.

PNAS2016. DOI: 10.1073/pnas.1607398113 (About DOIs).

By akfire1

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