Ghosts and gaps: Supernatural beliefs fill similar unknowns across cultures

Wherever you look in the world, you'll find supernatural explanations for events. Everything from earthquakes and disease to success in war are, in some groups, attributed to the acts of deities, demons, witches or spirits.

The long-standing 'god of the gaps' hypothesis holds that when people don't understand a phenomenon, they tend to infer that a supernatural agent has to be responsible. But does that only apply to events that have no clear scientific explanation, or for anything with an ambiguous cause? "We still know little about the gaps that people use religion to fill," comment Joshua Conrad Jackson at Northwestern University, and colleagues, in a new paper in Nature Human Behaviour. "If people use religious beliefs to explain the world, what about the world do they seek to explain?" 

To investigate this, Jackson and his colleagues scrutinised ethnographic texts on 114 different societies from all over the world. These groups ranged from nomadic hunter-gatherers in Africa to large, relatively complex societies, such as those found in Java.

The team looked for common explanations within each society of three natural phenomena: infectious disease, natural hazards - such as earthquakes, and naturally caused food scarcity. They did the same thing for three 'social phenomena': warfare, murder and theft. 

Of those investigated, only one society had no documented supernatural explanations for any of these events: the Burusho people of modern-day northern Pakistan. However, data for this group was limited. The team considers it highly possible that this society does have such explanations, but these were not documented by the ethnographer. 

Overall, an overwhelming 96% of the societies had supernatural explanations for disease, and 92% had supernatural explanations for natural causes of food scarcity. For natural hazards, the figure was 90%. For example, the Cayapa people from the rainforest of Ecuador attributed lightning to a sword-like weapon carried by the Thunder spirit. For the Aweikoma people of Brazil, sickness was caused by an attack from a spirit. 

The researchers also found supernatural explanations for social phenomena, including success in war. They even found one example of a belief related to theft, among the Toradja people of Sulawesi, Indonesia. In this society, people used maize kernels to divine whether a theft would be successful or not, and even to indicate whether the thief would find the occupants of the house fast asleep. 

However, people were much less likely to use supernatural explanations for social phenomena than for natural phenomena. Among social phenomena, 82% of societies held supernatural explanations for murder; for warfare, it was 67%; for theft, 26%.

"Our findings suggest humans around the world may be most likely to apply religious beliefs to explain phenomena that have no clearly responsible human agent," the team writes. In other words, when a person or group of people is not obviously to blame, humans tend to infer that a supernatural being or force is. 

Interestingly, the team's analyses also found that complex societies were more likely than simpler societies to have supernatural explanations for social phenomena. The researchers suggest that this might be because people who live in larger, more complex societies have weaker ties and trust others less, which may encourage them to explain negative social events as being down to factors such as witchcraft, demonic possession, or the 'evil eye'. 

The study does have some limitations. As the team acknowledges, the data is based on texts which were often written from an 18th or 19th century Western perspective. Though sources with clear racist biases were not included in analyses, the authors note that more subtle biases may still be present in the data set. They encourage replication attempts of their findings. This research also focused only on negative phenomena, so is unable to speak to whether results for positive, 'lucky' events may be different. 

While much of the ethnographic work captured by this study was on traditional societies of the past, these kinds of beliefs are common today. The team points out that some 90% of modern Muslim Tunisians believe the evil eye can cause harm, and that many American Christians believed that the Covid-19 pandemic was a form of divine punishment. 

The new findings add weight to the idea that supernatural explanations arise to explain gaps in human understanding. Cross-cultural differences in these beliefs and how they are applied may, the authors believe, be partially due to what humans within those groups find ambiguous or important within their own social structures.