Intriguing correlational findings should lead to crucial experiments. Fincher & Thornhill (F&T) quote research showing that the sight of disease symptoms activates the immune system. We need evidence of neurovisceral reactions (Porges Reference Porges, Fosha, Siegel and Solomon2010), as well as heightened ethnocentrism and religiosity, under (a) visual images (b) imagined encounters, (c) anticipating encounters, and (d) the actual presence of out-group members, in the presence or absence of disease and injury symptoms, compared with identical in-group encounters, and with other stimuli representing biological and psychological risk. A series of experiments following this design will clarify and advance the authors' claims.
References to behavioral research on religion in the target article are inconsistent. The authors state that “Religion is often defined as a value system that is based on supernatural phenomena (Boyer Reference Boyer2001)” (sect. 3.2, para. 3). Boyer (Reference Boyer2001) offers no such definition. The closest statement to a definition there states only that “Religion is about the existence and causal powers of non-observable entities and agencies” (p. 8). Boyer (Reference Boyer2001) does not use either “value system” or “supernatural phenomena” in his text. The term “supernatural phenomena” assumes that a supernatural realm exists, because a phenomenon is something known through the senses, but Boyer (Reference Boyer2001) states that religious claims are about non-observable entities and agencies.
How is a religious identity acquired? The authors state: “It is clear that religiousness, religious identities, and beliefs form at early ages” (sect. 6.2, para. 4), but they also offer a totally different portrayal earlier in the target article: “To learn the emotionality and associated language of a religion requires a long developmental (ontogenetic) exposure to the belief system”(sect. 3.2, para. 1). F&T argue that “Participation in a religion has certain costs for the participant, which include the time and effort involved in learning a religion and practicing it, the loss of opportunity to engage in other beneficial activities (opportunity costs), and risks such as the avoidance of modern medical care or extended fasting” sect. 3.2, para. 1).
This description conceives of religious involvement as individual “participation” – that is, taking an active part voluntarily – a matter of personal choice. Embracing a religious identity by choice, or even having alternatives, is rare and historically recent. The process is social rather than individual. Choice ends for most believers in an accident of birth which predicts best their lifetime religious trajectory. Through kinship we acquire, or inherit, not only religious identity, but also ethnicity, political affiliation, sports fanships, and other group attachments. Conversion, although enjoying scholarly attention, is a rarity among the world's billions of believers, as would be predicted from the F&T's own theory of assortative sociality (cf. Beit-Hallahmi, in press; Beit-Hallahmi & Argyle Reference Beit-Hallahmi and Argyle1997). Religious loyalty is psychologically tied to kinship loyalty. Conversion or religious exogamy are experienced as a betrayal.
Learning a particular religious system, just like learning “language or dialect, word use, dress, music, smell” (sect. 3.2, para. 8), starts – and ends, in most cases – in early childhood, within the family. Religious narratives, by their very nature, are accessible to young children, who absorb them without effort, just as they enjoy religious holidays. Children are a captive audience, and the imposition of religious beliefs by parents can be lethal. The authors mention “the avoidance of modern medical care” (sect. 3.2, para. 2) as one of the costs of “participation” in religion. This cost is usually borne by children who never had a choice, but die or suffer without proper health care (Asser & Swan Reference Asser and Swan1998). These extreme cases illustrate the powerlessness of children in relation to inherited and imposed religious identity.
F&T express surprising optimism when they refer to “an awareness of pathogens” (sect. 6.2, para. 4), and approvingly cite Curtis (Reference Curtis2007), who believes that humans have “intuitions” about pathogens around them. F&T state: “It is also clear that people develop an awareness of pathogens at relatively early ages (Siegal Reference Siegal1988)” (sect. 6.2, para. 4), and tie this to the early learning of religion. But the Siegal study was done in the United States and merely shows that young children in the First World remember the lessons they are being taught about hygiene.
Whether humans do indeed have an “awareness” (conscious?) or “intuition” (non-conscious?) of pathogens can be tested easily. Do individuals detect the presence of salmonella or HIV? Why is it that in West Africa those who wash corpses of cholera victims later prepare funeral feasts, which leads to renewed outbreaks of the disease? (See Gunnlaugsson et al. Reference Gunnlaugsson, Einarsdóttir, Angulo, Mentambanar, Passa and Tauxe1998; Sack & Siddique Reference Sack and Siddique1998.) If humans possessed such mental mechanisms, the history of human encounters with parasites would have been vastly different. We see no evidence of pathogen detection in numerous risky and lethal practices, and little evidence for any pathogen awareness till fairly recent times (vide Ignaz Semmelweis).
While pathogen awareness has been absent, intuitions about disease causation (including recent AIDS outbreaks) lead humankind to imagine angry gods punishing human transgressions or acts of sorcery (Forster Reference Forster1998; Murdock Reference Murdock1980). This is an important connection between religion, the belief in the spirit world, and health. We must wonder whether such fantasies, sometimes interpreted as expressing an unconscious processing of family tensions (Beit-Hallahmi Reference Beit-Hallahmi1989; Reference Beit-Hallahmi1996; Reference Beit-Hallahmi2010), are adaptive, and in what way.
The religion-biology connection is presented rather cheerfully when F&T state that “A large literature indicates that the relationships between religiosity and mental health and freedom from coronary disease and certain cancers typically are positive” (sect. 6.4, para. 7). Freedom from coronary disease and certain cancers? Reading Sloan (Reference Sloan2008) should serve as an antidote to such claims. How does this reported positive correlation between religion and health square with the authors' own finding of a worldwide positive correlation between religiosity and parasite-stress? Are the more religious people of Afghanistan healthier than the less religious people of Sweden? Ideas about the supernatural causation of illness are indeed found together with high parasite-stress and a reality of poor health.
Intriguing correlational findings should lead to crucial experiments. Fincher & Thornhill (F&T) quote research showing that the sight of disease symptoms activates the immune system. We need evidence of neurovisceral reactions (Porges Reference Porges, Fosha, Siegel and Solomon2010), as well as heightened ethnocentrism and religiosity, under (a) visual images (b) imagined encounters, (c) anticipating encounters, and (d) the actual presence of out-group members, in the presence or absence of disease and injury symptoms, compared with identical in-group encounters, and with other stimuli representing biological and psychological risk. A series of experiments following this design will clarify and advance the authors' claims.
References to behavioral research on religion in the target article are inconsistent. The authors state that “Religion is often defined as a value system that is based on supernatural phenomena (Boyer Reference Boyer2001)” (sect. 3.2, para. 3). Boyer (Reference Boyer2001) offers no such definition. The closest statement to a definition there states only that “Religion is about the existence and causal powers of non-observable entities and agencies” (p. 8). Boyer (Reference Boyer2001) does not use either “value system” or “supernatural phenomena” in his text. The term “supernatural phenomena” assumes that a supernatural realm exists, because a phenomenon is something known through the senses, but Boyer (Reference Boyer2001) states that religious claims are about non-observable entities and agencies.
How is a religious identity acquired? The authors state: “It is clear that religiousness, religious identities, and beliefs form at early ages” (sect. 6.2, para. 4), but they also offer a totally different portrayal earlier in the target article: “To learn the emotionality and associated language of a religion requires a long developmental (ontogenetic) exposure to the belief system”(sect. 3.2, para. 1). F&T argue that “Participation in a religion has certain costs for the participant, which include the time and effort involved in learning a religion and practicing it, the loss of opportunity to engage in other beneficial activities (opportunity costs), and risks such as the avoidance of modern medical care or extended fasting” sect. 3.2, para. 1).
This description conceives of religious involvement as individual “participation” – that is, taking an active part voluntarily – a matter of personal choice. Embracing a religious identity by choice, or even having alternatives, is rare and historically recent. The process is social rather than individual. Choice ends for most believers in an accident of birth which predicts best their lifetime religious trajectory. Through kinship we acquire, or inherit, not only religious identity, but also ethnicity, political affiliation, sports fanships, and other group attachments. Conversion, although enjoying scholarly attention, is a rarity among the world's billions of believers, as would be predicted from the F&T's own theory of assortative sociality (cf. Beit-Hallahmi, in press; Beit-Hallahmi & Argyle Reference Beit-Hallahmi and Argyle1997). Religious loyalty is psychologically tied to kinship loyalty. Conversion or religious exogamy are experienced as a betrayal.
Learning a particular religious system, just like learning “language or dialect, word use, dress, music, smell” (sect. 3.2, para. 8), starts – and ends, in most cases – in early childhood, within the family. Religious narratives, by their very nature, are accessible to young children, who absorb them without effort, just as they enjoy religious holidays. Children are a captive audience, and the imposition of religious beliefs by parents can be lethal. The authors mention “the avoidance of modern medical care” (sect. 3.2, para. 2) as one of the costs of “participation” in religion. This cost is usually borne by children who never had a choice, but die or suffer without proper health care (Asser & Swan Reference Asser and Swan1998). These extreme cases illustrate the powerlessness of children in relation to inherited and imposed religious identity.
F&T express surprising optimism when they refer to “an awareness of pathogens” (sect. 6.2, para. 4), and approvingly cite Curtis (Reference Curtis2007), who believes that humans have “intuitions” about pathogens around them. F&T state: “It is also clear that people develop an awareness of pathogens at relatively early ages (Siegal Reference Siegal1988)” (sect. 6.2, para. 4), and tie this to the early learning of religion. But the Siegal study was done in the United States and merely shows that young children in the First World remember the lessons they are being taught about hygiene.
Whether humans do indeed have an “awareness” (conscious?) or “intuition” (non-conscious?) of pathogens can be tested easily. Do individuals detect the presence of salmonella or HIV? Why is it that in West Africa those who wash corpses of cholera victims later prepare funeral feasts, which leads to renewed outbreaks of the disease? (See Gunnlaugsson et al. Reference Gunnlaugsson, Einarsdóttir, Angulo, Mentambanar, Passa and Tauxe1998; Sack & Siddique Reference Sack and Siddique1998.) If humans possessed such mental mechanisms, the history of human encounters with parasites would have been vastly different. We see no evidence of pathogen detection in numerous risky and lethal practices, and little evidence for any pathogen awareness till fairly recent times (vide Ignaz Semmelweis).
While pathogen awareness has been absent, intuitions about disease causation (including recent AIDS outbreaks) lead humankind to imagine angry gods punishing human transgressions or acts of sorcery (Forster Reference Forster1998; Murdock Reference Murdock1980). This is an important connection between religion, the belief in the spirit world, and health. We must wonder whether such fantasies, sometimes interpreted as expressing an unconscious processing of family tensions (Beit-Hallahmi Reference Beit-Hallahmi1989; Reference Beit-Hallahmi1996; Reference Beit-Hallahmi2010), are adaptive, and in what way.
The religion-biology connection is presented rather cheerfully when F&T state that “A large literature indicates that the relationships between religiosity and mental health and freedom from coronary disease and certain cancers typically are positive” (sect. 6.4, para. 7). Freedom from coronary disease and certain cancers? Reading Sloan (Reference Sloan2008) should serve as an antidote to such claims. How does this reported positive correlation between religion and health square with the authors' own finding of a worldwide positive correlation between religiosity and parasite-stress? Are the more religious people of Afghanistan healthier than the less religious people of Sweden? Ideas about the supernatural causation of illness are indeed found together with high parasite-stress and a reality of poor health.