In a study encompassing several distinct populations, Joseph Henrich and collaborators conclude that both participation in markets and belief in a world religion promote fairness norms that facilitate emergence of large-scale societies. The study was described in a recent issue of The Economist:
For the evolutionarily minded, the existence of fairness is a puzzle. What biological advantage accrues to those who behave in a trusting and co-operative way with unrelated individuals? And when those encounters are one-off events with strangers it is even harder to explain why humans do not choose to behave selfishly. The standard answer is that people are born with an innate social psychology that is calibrated to the lives of their ancestors in the small-scale societies of the Palaeolithic. Fairness, in other words, is an evolutionary hangover from a time when most human relationships were with relatives with whom one shared a genetic interest and who it was generally, therefore, pointless to cheat.
The problem with this idea is that the concept of fairness varies a lot, depending on which society it happens to come from—something that does not sit well with the idea that it is an evolved psychological tool. Another suggestion, then, is that fairness is a social construct that emerged recently in response to cultural changes such as the development of trade. It may also, some suggest, be bound up with the rise of organised religion.
Joseph Henrich at the University of British Columbia and his colleagues wanted to test these conflicting hypotheses. They reasoned that if notions of fairness are, indeed, calibrated to the Palaeolithic, then any variation from place to place should be random. If such notions are cultural artefacts, though, they will vary systematically with some aspect of society….
The results back a cultural explanation of fairness—or, at least, of the variable levels of fairness found in different societies. … People living in communities that lack market integration display relatively little concern with fairness or with punishing unfairness in transactions. Notions of fairness increase steadily as societies achieve greater market integration. People from better-integrated societies are also more likely to punish those who do not play fair, even when this is costly to themselves….
Dr Henrich also, however, found that the sense of fairness in a society was linked to the degree of its participation in a world religion. Participation in such religion led to offers in the dictator game that were up to 10 percentage points higher than those of non-participants.
World religions such as Christianity, with their moral codes, their omniscient, judgmental gods and their beliefs in heaven and hell, might indeed be expected to enforce notions of fairness on their participants, so this observation makes sense. From an economic point of view, therefore, such judgmental religions are actually a progressive force. That might explain why many societies that have embraced them have been so successful, and thus why such beliefs become world religions in the first place.
So there you have it: both belief in world religions and participation in markets seem to be associated with fairness.
The Henrich et al. study was published as “Markets, Religion, Community Size, and the Evolution of Fairness and Punishment,” Science (March 19, 2010). As summarized in the abstract:
Large-scale societies in which strangers regularly engage in mutually beneficial transactions are puzzling. The evolutionary mechanisms associated with kinship and reciprocity, which underpin much of primate sociality, do not readily extend to large unrelated groups. Theory suggests that the evolution of such societies may have required norms and institutions that sustain fairness in ephemeral exchanges. If that is true, then engagement in larger-scale institutions, such as markets and world religions, should be associated with greater fairness, and larger communities should punish unfairness more. Using three behavioral experiments administered across 15 diverse populations, we show that market integration (measured as the percentage of purchased calories) positively covaries with fairness while community size positively covaries with punishment. Participation in a world religion is associated with fairness, although not across all measures. These results suggest that modern prosociality is not solely the product of an innate psychology, but also reflects norms and institutions that have emerged over the course of human history.
If you have questions about how the study was conducted, how they measured market integration and fairness, etc., check out the extensive supplemental information also posted at the Science website.