Exposure to religious and civic concepts both make people more generous. Credit: Punchstock

A belief in God may have promoted the evolution of cooperative behaviour, say Canadian psychologists. They found that priming people with religious concepts makes them more generous — regardless of whether they declare themselves to be believers.

Notions of civic responsibility also promote cooperation, suggesting that religion might encourage altruism by invoking an omniscient judge of behaviour.

"One idea that we seriously considered was that God, to those who believe, is a supernatural policing agent," says psychologist Azim Shariff of the University of British Columbia in Vancouver. "We started to wonder whether civic [responsibilities] and religion operated all that differently within the unconscious mind."

To investigate how belief in supernatural agents might influence cooperation, Shariff and his colleague Ara Norenzayan used a word game to stealthily introduce religious concepts to their subjects.

Participants had to unscramble five-word sentences, dropping an extraneous word from each to create a grammatical four-word sentence. For example, "felt she eradicate spirit the" would become "she felt the spirit," and "dessert divine was fork the" could become "the dessert was divine." A control group unscrambled sentences made up of non-spiritual words.

Share and share alike

After this exercise, the participants played an economic decision-making game. Each player was given $10 to share with an anonymous recipient.

Participants primed with religious concepts gave their partner an average of $4.22, compared with only $1.84 in the control group. But those who declared themselves religious before the study were no more generous than non-believers.

"The effect of the religious prime was both large and surprising, especially considering that during exit interviews the participants were unaware of having been religiously primed," says Shariff.

A second study introduced a third group, primed with words associated with civic responsibility such as "jury", contract", and "police." This group behaved almost identically to that primed with religious concepts.

Common functions

"This research is really ground-breaking," says social psychologist Adam Cohen at Arizona State University, Tempe. "The subtle prime of religion is one of the greatest strengths of this research because it does not tip people off to what the study is about."

But why such priming makes people more charitable is unclear. "The fact that primes to civic institutions also produced more charitable behaviour gives some clues," he says. "Perhaps religion and these civic institutions have certain functions or effects in common."

Whether religion and civic responsibilities are equally effective spurs to cooperation remains to be seen. "We can't compare the relative strengths of religion and civics, or draw tight analogies to real-world situations," says Shariff. "What we can do is identify that both concepts have substantial effects on prosocial behaviour."

Visit our newsblog to read and post comments about this story.