A tough climate might make for tough men and women, but with history and social forces on its side, it will also most likely make for a pretty tough god.
That's according to a study out today in Proceedings of the National Academy of Sciences, which suggests one can predict with a high level of accuracy whether a society has a moralizing high god—one thought to govern reality, intervene in our affairs, and enforce or at least support moral behavior—using ecological data in conjunction with just a few political, economic, and agricultural measures.
Scientists have been debating for some time what influence ecology might have on the religious aspects of our culture. It shouldn't come as a big surprise that culture and the natural environment interact, and there's reason to believe that believing in god might increase cooperation even in anonymous interactions. Those two factors suggest that societies who most need to cooperate—for example, groups living in places with few resources or unreliable agricultural conditions—might have the sort of gods that would encourage cooperation. Yet no one's quite sure whether that argument works out in practice.
In most societies they considered, climate stability meant predictable, generally good living conditions, making deity-encouraged cooperation less necessary.
To find out, a team of biologists, linguists, and others collected data on 583 societies listed in the Ethnographic Atlas. The atlas itself includes information on each ethnic group's location, religion, agriculture, and the extent to which societies organized themselves into political units beyond the local level, among other factors. To take account of potential outside influence on a culture, the team also recorded the religious beliefs of each society's 10 nearest neighboring societies. To bring climate into the mix, the team gathered historical data on rainfall, temperature, biodiversity, and primary production—roughly, a measure of how much solar energy plants convert into forms they can store for later.
Data in hand, the researchers first boiled the ecological data down into two variables, resource abundance and climate stability. Taking those two factors as well as the ethnographic data into account, the team examined a subset of 389 societies and found that political complexity and proximity to societies with moralistic high gods increased the probability a society had a moralistic deity, while societies with the most resources tended to be less likely to have such a god. Increasing climate stability for the most part had the same effect as increasing resources: In most societies they considered, climate stability meant predictable, generally good living conditions, making deity-encouraged cooperation less necessary.
Not only did climate help shape religious beliefs, but including it in the team's model also led to remarkably accurate predictions. Testing the model they'd developed using the first two-thirds of the data on the remaining third, the researchers found they could correctly classify 91 percent of those cultures as having a moralistic deity or not.