The Gods are Watching, Behave!: A Selection from Joseph Henrich’s The WEIRDest People in the World (2020)

“To see primes in action, let’s head into the medina of Marrakesh, in Morocco. Inside the old city walls, among the maze-like streets, Muslim shopkeepers played a modified Dictator Game. Here, the Muslim call to prayer sounds five times per day for 5 to 10 minutes from minarets around the city. That’s our prime. In the experiment, 69 shopkeepers chose from among three ways to allocate the local currency—dirhams—between themselves and a charity. They could: (A) keep 20 dirhams for themselves and give 0 to charity; (B) keep 10 for themselves and give 30 to charity; or (C) take nothing and give 60 to charity. Twenty dirhams was about enough money to buy lunch or take a 15-minute taxi ride. The experiment was administered either during the call to prayer or between calls.

Here’s the key question: Did hearing the call to prayer in the background while considering their choice in this experiment influence these small business owners?

You bet. During the call to prayer, 100 percent of shopkeepers gave all of the money to charity (choice C). At other times, the percentage of participants giving it all to charity dropped to 59 percent. This is surprising, because these shopkeepers earn a living by hawking goods like dried fruits, local crafts, and handwoven rugs, and spend their days haggling over much smaller sums. Nevertheless, although they routinely hear the call, it still influences their behavior in significant ways.

Such embedded primes influence Christians as well, creating the Sunday effect. In a study conducted over two months, Christians were more likely to participate in charitable efforts via email on Sundays (with some spillover into Mondays) than on other days of the week. By Saturday, the charitable inclinations of Christians hit their weekly low, and were not distinguishable from those of nonreligious people. But, then Sunday came, and many Christians got a ritualized booster shot that elevated their charitable inclinations. Unlike the faithful, nonreligious people reveal no such weekly cycle.

The Sunday effect also shows up in the use of online pornography across U.S. states. While on average there’s little variation across states in porn usage, states with more religious populations reveal a weekly cycle that tracks the charity patterns above. People from more religious states apparently watch less porn on Sundays, but then compensate for this ‘porn deficit’ by watching more over the rest of the week. These results are predictable, since the Christian God is famously obsessed with both charity and sex—i.e., not having it or even thinking about it.

By giving us a glimpse into the subtle power of religion in our daily decision-making, studies like these uncover the psychological footprints left by cultural evolution. They reveal how, operating outside of our conscious awareness, supernatural beliefs and ritual practices can motivate the faithful to make personally costly decisions, treat strangers more fairly, and contribute to public goods like charities (and avoid porn).”—Joseph Henrich, The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous (2020)