An analysis of 583 cultures shows that challenging environmental conditions, such as floods and famines, lead cultures to adopt beliefs in moralizing, high gods. The research may help explain how and why certain religions emerged, including Judaism, Christianity, and Islam.
Prior to this study, anthropologists were inclined to explain the onset of religion as the result of either cultural or environmental factors, but not both. The new study corrects this by describing how complex practices and traits emerged from a dynamic mixture of ecological, historical, and cultural variables.
At an intuitive level this research makes sense. In the absence of scientific explanations, our ancestors were forced to conclude — quite reasonably — that hardships such as plagues, floods, and famines were instigated by supernatural forces beyond their comprehension and control, that human behavior may have been responsible for bringing it on, and that "corrections" in this behavior might help prevent future problems. What's more, the socio-cultural adaptations required to survive these hardships inevitably led to dramatic changes in human organization, cooperation, and moral values.
"When life is tough or when it's uncertain, people believe in big gods," noted Russell Gray in a statement. He's a professor at the University of Auckland and a founding director of the Max Planck Institute for History and the Sciences in Jena, Germany. "Prosocial behavior maybe helps people do well in harsh or unpredictable environments," he says.
Indeed, just as certain physical adaptations confer advantages to specific populations of animals, it's conceivable that belief in judgmental and powerful gods might also be advantageous for human cultures in harsh environments. It can be understood as a memetic coping mechanism, and as a way to better understand and reconcile the world.
What's more, belief in moralizing high gods tends to promote cooperation among humans; belief in an almighty and powerful god — where followers are required to live by certain moral rules — unite communities living in harsh environments and when food is scarce.
Accordingly, Gray and his colleagues were able to show a strong correlation between belief in high gods who enforce a moral code with other societal characteristics, such as political complexity (i.e., a social hierarchy beyond the local community) and the practice of animal husbandry. Other traits induced by harsh conditions include cooperation, fairness, and honesty.
"Although some aspects of religion appear maladaptive, the near universal prevalence of religion suggests that there's got to be some adaptive value and by looking at how these things vary ecologically, we get some insight," added Gray.
For the study, a research team was assembled that included experts in biology, ecology, linguistics, anthropology, and religious studies. Ethnographic data of societies that believe in moralizing, high gods were plotted on a map. The researchers discovered that their global distribution was similar to a map of cooperative breeding in birds — a parallel which suggested that ecological factors may play a role.
Distribution of societies that believe in moralizing, high gods (blue) and those that do not (red). Light gray shading indicates lower potential for plant growth with the darker areas signifying high potential. (Carlos Botero)
They then used historical, social, and ecological data for 583 societies to show the multifaceted relationship between belief in moralizing, high gods and external variables. Unlike previous work, which considered rough estimates of ecological conditions, the new study used high-resolution global datasets for variables like plant growth, precipitation, and temperature. The researchers also drilled through the Ethnographic Atlas (an electronic database of more than a thousand societies from the 20th century) for geographic coordinates and sociological data, including the presence of religious beliefs, agriculture, and animal husbandry.
Religions studied included Christianity, Islam, and rarer religions such as Zahv, the belief system of the Akha people in south-east Asia. Interestingly, some scholars suspect that dramatic changes in climate around 535 AD may have been responsible for the rise and spread of Islam around that time.
Overall, this approach was successful in predicting the global distribution of beliefs in judgmental and powerful gods with an accuracy of 91%.
"The emerging picture is neither one of pure cultural transmission nor of simple ecological determinism, but rather a complex mixture of social, cultural, and environmental influences," conclude the authors in the study, which now appears at PNAS. "Our methods and findings provide a blueprint for how the increasing wealth of ecological, linguistic, and historical data can be leveraged to understand the forces that have shaped the behavior of our own species."
That said, the authors warn against oversimplifying the spread of religions, adding that they hope to study how trade, conquest, and the spread of language also played a role.