Fincher & Thornhill (F&T) document a large and predicted correlation between parasite-stress and religiosity cross-nationally and within the United States. F&T also present a powerful theoretical and empirical case for the effects of parasite-stress on the promotion of boundaries between in-group and out-groups, including the generation and maintenance of ethnocentrism and xenophobia. We argue, however, that the United States may be more religious than can be accounted for by parasite-stress. This greater religiosity (relative to cultures with similar parasite-stress levels) might be attributable to greater sensitivity to immigration, which may hyperactivate evolved mechanisms that motivate avoidance of potential carriers of novel parasites.
Historically, the United States has been a Mecca for immigration and for concerns about immigration: from the first settlers on Native American soil, to the enormous influx of Europeans in the early 1900s, to today's perpetual dialogue on the fear or protection of Hispanic and Middle Eastern immigrants. Recent research indicates that the United States is less favorably disposed toward immigrants than are most European countries (who, in turn, are less religious; e.g., Isernia et al. Reference Isernia, Martin and Diehl2010). This apparent hypersensitivity to immigration in the United States could be the product of several factors. First, since the inception of the country, immigration of one group or another has been cause for concern among native citizens. The Irish, the Polish, the Japanese, and the Russians are each groups that have been the focus of concern coinciding with their mass immigration to the United States. This intense and typically negative concern about immigrants and immigration might reflect hypersensitivity to the changes and threats they bring. Out-groups, including immigrants, may be (or are perceived to be) “lacking knowledge of and therefore violating local customs or norms, many of which, like hygiene and methods of food preparation, may prevent infection from local parasites” (target article, sect. 2.1, para. 3). These violations are registered as threats by our “behavioral immune system,” which F&T explain is “comprised of ancestrally adaptive feelings, attitudes, and values about and behaviors toward out-group and in-group members, caution about unwillingness to interact with out-group people, and prejudice against people perceived as unhealthy, contaminated, or unclean” (sect. 2.1, para. 1). To many Americans, immigrants are seen as just that: “unhealthy, contaminated, or unclean.” But why is this? Perhaps the American media and other interest groups are priming individuals for fear of parasitic infection with certain “keywords” in connection to immigrants.
It is not uncommon to hear remarks from conservative personalities, politicians, and news sources comparing immigrants to subhuman species. The use of terms that compare immigrants to particular nonhuman species seems to justify the treatment of them as such (see Livingstone Smith Reference Livingstone Smith2011). Representative Curry Todd (Reference Todd2010), a republican from Tennessee, commented during a Joint Fiscal Review Committee meeting on a medical program that covers Tennessee children, including immigrant children: “We can go out there like rats, and multiply then, I guess,” in reference to the pregnant women that come into America. Michael Savage (Reference Savage2006), a conservative talk-show host, referred to Mexican immigrants as “vermin” and Rush Limbaugh (Reference Limbaugh2005), a conservative radio host, referred to immigrants as an invasive species: “So invasive species like mollusks and spermatozoa are not good, and we've got a federal judge say, ‘You can't bring it in here,’ but invasive species in the form of illegal immigration is fine and dandy – bring ‘em on, as many as possible.” F&T summarize the results of recent research on diverse Western samples which indicate:
that scores among individuals on scales that measure the degree of xenophobia and ethnocentrism correspond to chronic individual differences in perceived vulnerability to infectious disease; those who perceive high disease risk are more xenophobic and ethnocentric than those who perceive low disease risk. Importantly, this research also shows that xenophobia and ethnocentrism within individuals increases under experimental primes of greater disease salience in the current environment. (sect. 2.1, para. 13)
The relationship of hypersensitivity to immigrants and increased religiosity might be attributable, in part, to the select terms and vitriol often used to describe immigrants by the religious conservative media. Likening immigrants to “vermin” and “rats” may prime disease salience and, therefore, motivate greater assortative sociality (see also Livingstone Smith Reference Livingstone Smith2011).
A second possible explanation for the apparent US hypersensitivity to immigration is the relative isolation of the United States from other countries. The mainland is bordered by just two countries. Latin American immigrants tend to be treated more poorly than are Canadian immigrants, certainly by the conservative religious media and other interest groups. This might be attributable to the perceived potential threat posed by immigrants from countries with higher parasite-stress, such as Mexico and other Latin American countries. This difference in treatment of immigrants might be exacerbated by the fact that Mexicans and other Latin Americans comprise a much larger proportion of immigrants than do Canadians. The more striking cultural differences and associated perceived threats between Americans and Latin Americans might therefore be doubly threatening, given the much larger immigrant population. In addition, because the US mainland shares its borders with just two countries, its citizens may be less accustomed to cross-national travel. In Europe, in contrast, one can traverse through multiple countries within a day's time. Individuals in the United States therefore may be more aware of immigrants entering the country, simply because immigration is more apparent when it occurs.
We speculate that, in combination with parasite-stress, increased sensitivity to immigration into the United States (with immigrants perceived as potential carriers of novel parasites) hyperactivates evolved mechanisms that motivate assortative sociality. The current levels of parasite-stress in combination with the sensitivity to immigration might explain the collectivistic and especially religious nature of the United States, relative to other countries with similar parasite-stress levels. Furthermore, as immigrants enter the United States, native individuals within areas of high parasite-stress may be more likely to enforce the dividing line between in-group and out-group, promoting and maintaining ethnocentric and xenophobic behaviors and in-group connectivity with religious activities. The elevated parasite-stress in combination with hypersensitivity to immigration might form a perfect storm for increased religiosity as protection against novel infectious diseases.
Fincher & Thornhill (F&T) document a large and predicted correlation between parasite-stress and religiosity cross-nationally and within the United States. F&T also present a powerful theoretical and empirical case for the effects of parasite-stress on the promotion of boundaries between in-group and out-groups, including the generation and maintenance of ethnocentrism and xenophobia. We argue, however, that the United States may be more religious than can be accounted for by parasite-stress. This greater religiosity (relative to cultures with similar parasite-stress levels) might be attributable to greater sensitivity to immigration, which may hyperactivate evolved mechanisms that motivate avoidance of potential carriers of novel parasites.
Historically, the United States has been a Mecca for immigration and for concerns about immigration: from the first settlers on Native American soil, to the enormous influx of Europeans in the early 1900s, to today's perpetual dialogue on the fear or protection of Hispanic and Middle Eastern immigrants. Recent research indicates that the United States is less favorably disposed toward immigrants than are most European countries (who, in turn, are less religious; e.g., Isernia et al. Reference Isernia, Martin and Diehl2010). This apparent hypersensitivity to immigration in the United States could be the product of several factors. First, since the inception of the country, immigration of one group or another has been cause for concern among native citizens. The Irish, the Polish, the Japanese, and the Russians are each groups that have been the focus of concern coinciding with their mass immigration to the United States. This intense and typically negative concern about immigrants and immigration might reflect hypersensitivity to the changes and threats they bring. Out-groups, including immigrants, may be (or are perceived to be) “lacking knowledge of and therefore violating local customs or norms, many of which, like hygiene and methods of food preparation, may prevent infection from local parasites” (target article, sect. 2.1, para. 3). These violations are registered as threats by our “behavioral immune system,” which F&T explain is “comprised of ancestrally adaptive feelings, attitudes, and values about and behaviors toward out-group and in-group members, caution about unwillingness to interact with out-group people, and prejudice against people perceived as unhealthy, contaminated, or unclean” (sect. 2.1, para. 1). To many Americans, immigrants are seen as just that: “unhealthy, contaminated, or unclean.” But why is this? Perhaps the American media and other interest groups are priming individuals for fear of parasitic infection with certain “keywords” in connection to immigrants.
It is not uncommon to hear remarks from conservative personalities, politicians, and news sources comparing immigrants to subhuman species. The use of terms that compare immigrants to particular nonhuman species seems to justify the treatment of them as such (see Livingstone Smith Reference Livingstone Smith2011). Representative Curry Todd (Reference Todd2010), a republican from Tennessee, commented during a Joint Fiscal Review Committee meeting on a medical program that covers Tennessee children, including immigrant children: “We can go out there like rats, and multiply then, I guess,” in reference to the pregnant women that come into America. Michael Savage (Reference Savage2006), a conservative talk-show host, referred to Mexican immigrants as “vermin” and Rush Limbaugh (Reference Limbaugh2005), a conservative radio host, referred to immigrants as an invasive species: “So invasive species like mollusks and spermatozoa are not good, and we've got a federal judge say, ‘You can't bring it in here,’ but invasive species in the form of illegal immigration is fine and dandy – bring ‘em on, as many as possible.” F&T summarize the results of recent research on diverse Western samples which indicate:
that scores among individuals on scales that measure the degree of xenophobia and ethnocentrism correspond to chronic individual differences in perceived vulnerability to infectious disease; those who perceive high disease risk are more xenophobic and ethnocentric than those who perceive low disease risk. Importantly, this research also shows that xenophobia and ethnocentrism within individuals increases under experimental primes of greater disease salience in the current environment. (sect. 2.1, para. 13)
The relationship of hypersensitivity to immigrants and increased religiosity might be attributable, in part, to the select terms and vitriol often used to describe immigrants by the religious conservative media. Likening immigrants to “vermin” and “rats” may prime disease salience and, therefore, motivate greater assortative sociality (see also Livingstone Smith Reference Livingstone Smith2011).
A second possible explanation for the apparent US hypersensitivity to immigration is the relative isolation of the United States from other countries. The mainland is bordered by just two countries. Latin American immigrants tend to be treated more poorly than are Canadian immigrants, certainly by the conservative religious media and other interest groups. This might be attributable to the perceived potential threat posed by immigrants from countries with higher parasite-stress, such as Mexico and other Latin American countries. This difference in treatment of immigrants might be exacerbated by the fact that Mexicans and other Latin Americans comprise a much larger proportion of immigrants than do Canadians. The more striking cultural differences and associated perceived threats between Americans and Latin Americans might therefore be doubly threatening, given the much larger immigrant population. In addition, because the US mainland shares its borders with just two countries, its citizens may be less accustomed to cross-national travel. In Europe, in contrast, one can traverse through multiple countries within a day's time. Individuals in the United States therefore may be more aware of immigrants entering the country, simply because immigration is more apparent when it occurs.
We speculate that, in combination with parasite-stress, increased sensitivity to immigration into the United States (with immigrants perceived as potential carriers of novel parasites) hyperactivates evolved mechanisms that motivate assortative sociality. The current levels of parasite-stress in combination with the sensitivity to immigration might explain the collectivistic and especially religious nature of the United States, relative to other countries with similar parasite-stress levels. Furthermore, as immigrants enter the United States, native individuals within areas of high parasite-stress may be more likely to enforce the dividing line between in-group and out-group, promoting and maintaining ethnocentric and xenophobic behaviors and in-group connectivity with religious activities. The elevated parasite-stress in combination with hypersensitivity to immigration might form a perfect storm for increased religiosity as protection against novel infectious diseases.