You just gotta love anthropology. A new study in the Proceedings of the Royal Society B argues that "Pathogen prevalence predicts human cross-cultural variablity in individualism/collectivism."
Basically, what these anthropologists did was correlate the results of four previously published cross-cultural surveys that score various cultures as being more collectivist or more individualist with some pathogen prevalence indices. I don't have a link to the whole article but let me quote at length some of their findings below:
Disease-causing pathogens represent significant ecological hazards that must be managed or avoided all together. Selection pressures imposed by pathogens appear to have had an influence on the psychology and social behaviour of many species, including primates (Freeland 1976; Møller et al. 1993; Loehle 1995). Humans are no exception. Infectious diseases have been agents of morbidity and mortality throughout human history (Anderson & May 1991; Ewald 1994; Dobson & Carper 1996; Wolfe et al. 2007), and a growing body of empirical research indicates that people possess psychological mechanisms that serve the function of antipathogen defence. For instance, ethnocentrism, xenophobia and other specific forms of interpersonal prejudice appear to result, in part, from the operation of these mechanisms (e.g. Faulkner et al. 2004; Navarrete & Fessler 2006; Park et al. 2007).
As is the case with immune defence more generally (Zuk & Stoehr 2002; Hanssen et al. 2004), there are potential costs as well as benefits associated with psychological and behavioural antipathogen defences. One consequence is the activation of these mechanisms contingent upon cues indicating vulnerability to the transmission of pathogens. To the extent that individuals are more vulnerable (or perceive themselves to be more vulnerable) to the hazards posed by infectious diseases, those individuals show stronger evidence of cognitions and attitudes that serve an antipathogen defence function (Faulkner et al. 2004; Navarrete & Fessler 2006; Navarrete et al. 2007; Park et al. 2007; Schaller & Duncan 2007).
This sort of contingency may manifest not merely in differences between individual persons, but in differences between human cultures. To the extent that particular forms of social behaviour (and the specific psychological mechanisms underlying those behaviours) serve an antipathogen defence function, then those behaviours (and the underlying mechanisms) are more likely to characterize the cultural populations within which there has historically been greater prevalence of disease-causing pathogens. Prior research shows that worldwide variability in pathogen prevalence predicts specific kinds of cultural differences, including differences in food preparation (Sherman & Billing 1999), marriage structures (Low 1990), parenting practices (Quinlan 2007) and mate preferences (Gangestad et al. 2006). We focus here on the multifaceted value systems of individualism and collectivism, which are fundamental to social scientists' descriptions of culture and cross-cultural differences (e.g. Triandis 1995; Hofstede 2001). Indeed, it has been suggested that the individualism/collectivism dimension 'may ultimately prove to be the most important dimension for capturing cultural variation' (Heine 2008, p. 189). But it has remained largely a riddle as to why some cultures are more individualistic while others are more collectivistic. We suggest that collectivism (in contrast to individualism) serves an antipathogen defence function, and thus is more likely to emerge and persist within populations that historically have been characterized by a greater prevalence of pathogens.
The logical basis of this hypothesis is evident in at least two defining features of collectivistic (versus individualistic) value systems. First, collectivists make sharp distinctions between coalitional in-groups and out-groups, whereas among individualists the in-group/out-group distinction is typically weaker (Gelfand et al. 2004). A consequence is that collectivists are more wary of contact with foreigners and other out-group members (Sagiv & Schwartz 1995). This xenophobic attitude can serve an effective antipathogen function by inhibiting exposure to novel pathogens. A second, but no less critical, distinction between these cultural value systems lies in their different emphases on conformity versus the tolerance for deviance. Collectivism is characterized by a strong value placed on tradition and conformity, whereas individualism is characterized by a greater tolerance for (and encouragement of ) deviation from the status quo (Oishi et al. 1998; Cukur et al. 2004). Given that many specific traditions and norms (such as those pertaining to food preparation; e.g. Sherman & Billing 1999) can serve as buffers against pathogen transmission, deviance from the status quo may pose a contagion risk to self and others, whereas conformity helps to maintain the integrity of these ritualized buffers against disease. In sum, the behavioural manifestations of collectivism (compared with the behavioural manifestations of individualism) are more likely to provide defence against the dangers posed by pathogens.
Individualistic values may promote other kinds of functional benefits. For example, the discovery or spread of beneficial new technologies may occur more frequently when individuals are encouraged to deviate from existing traditions and engage in interactions with non-group members. In geographical regions characterized by relatively low pathogen stress, the benefits of collectivism (in terms of antipathogen defence) may be minimal, compared with the benefits associated with individualism. Under these ecological circumstances, individualistic values may be more adaptive. However, within geographical regions characterized by a greater prevalence of pathogens, the functional benefits of collectivism would also be greater, and may outweigh whatever benefits are conferred by individualistic tendencies. Under these circumstances, collectivistic values are likely to be more adaptive. It follows that worldwide variation in the historical prevalence of pathogens should predict contemporary cultural tendencies towards individualistic versus collectivistic values.
Which is what the researchers found. To wit:
…the regional prevalence of pathogens has a strong positive correlation with cultural indicators of collectivism and a strong negative correlation with individualism.
Also particularly charming was the anthropological description of "collectivism" was being ethnocentric, tradition-bound, conformist and xenophobic. Communism/socialism is always a reversion to tribalism.
*Irony alert–last time I tried what I thought was a puckish headline aimed at making fun of a new study, I got accused of all manner of cherrypicking, intellectual dishonesty and so forth.
Hat tip to Matt Hogan.