Azim Shariff at the University of Oregon in Eugene and his colleagues compared global data on people's beliefs in the afterlife with worldwide crime data collated by the United Nations Office on Drugs and Crime. In total, Shariff's team looked at data covering the beliefs of 143,000 individuals across 67 countries and from a variety of religious backgrounds.

In most of the countries assessed, people were more likely to report a belief in heaven than in hell. Using that information, the team could calculate the degree to which a country's rate of belief in heaven outstrips its rate of belief in hell.

Even after the researchers had controlled for a host of crime-related cultural factors – including GDP, income inequality, population density and life expectancy – national crime rates were typically higher in countries with particularly strong beliefs in heaven but weak beliefs in hell.

"Belief in a benevolent, forgiving god could license people to think they can get away with things," says Shariff – although he stresses that this conclusion is speculative, and that the results do not necessarily imply causality between religious beliefs and crime rates.

"There are a number of possible causal pathways," says Richard Sosis, an anthropologist at the University of Connecticut in Storrs, who was not involved in the study. The most likely interpretation is that there are intervening variables at the societal level – societies may have values that are similarly reflected in their legal and religious systems.

In a follow-up study, yet to be published, Shariff and Amber DeBono of Winston–Salem State University in North Carolina primed volunteers who had Christian beliefs by asking them to write variously about God's forgiving nature, God's punitive nature, a forgiving human, a punitive human, or a neutral subject. The volunteers were then asked to complete anagram puzzles for a monetary reward of a few cents per anagram.

Participants were given the opportunity to commit petty theft, with no chance of being caught, by lying about the number of anagrams they had successfully completed. Shariff's team found that those participants who had written about a forgiving god claimed nearly $2 more than they were entitled to under the rules of the game, whereas those in the other groups awarded themselves less than 50 cents more than they were entitled to.