Cooperation requires acting and working together for the mutual benefits of the members of the in-group. Accordingly, it is generally thought and also supported by the empirical evidence that religiosity evolved with the object of constructing large-scale societies where the anonymous interaction among members of society is crucial (Norenzayan & Shariff, 2008; Atran & Heinrich, 2010; Preston & Ritter, 2013; Shariff & Norenzayan, 2007; Rand et al., 2014). Thus, generosity and altruism are more common in religious societies which have big Gods, namely; İslam, Christianity and Judaism (Norenzayan, 2013). These religions have big Gods who are also concerned about morality of humans which is also thought to lead to prosocial behavior.
There is a body of research on the relation between religion and prosocial behavior coming from generally priming literature. For instances, Pichon et al. (2007) found that priming with religious words increased the charity intentions. Another found that when Protestants were primed with religious words, they became more cooperative (Benjamin et al., 2010). A third one used a supraliminal priming procedure in which participants are primed with some target words (God, prophets, divine, spirit, sacred) in an unscramble five-word sentences to form grammatically four-word sentences and found that priming with religious target words increased generosity in an anonymous dictator game (Shariff & Norenzayan, 2007). Ahmet & Salas (2011) extended the results and indicated the robustness of this effect with both dictator game and prisoners dilemma. Moreover, in another leading study, when people will be subliminally primed with religious concepts in which participants will be flashed on a screen for 80 milliseconds, they showed honesty although they have a chance to cheat in a given condition (Randolph-Seng & Nielsen, 2007).
On the other hand, there are some studies which contradict with the prosocial effect of religion. Johnson, Rowatt & LoBouff (2010) showed that when people were supraliminally primed with religious words especially with Christian words, they showed an aggressiveness and hostility toward out-groups such as non-Christians and homosexuals. Johnson et al. (2010) also showed that priming with Christian words (bible, Jesus) increased negative attitudes toward both Atheists and Muslims. Thus, the prosocial effect of religion is not clear.
A recent finding claims that religious priming does not only activate religious concepts, rather, they also activate reward cognitions which are related to heaven or salvation; thus, the positive and prosocial outcome of religious priming might be due to only religiosity, their reward load or a combination of both (Harrell, 2012). Accordingly, Pichon et al. (2007) had also showed that if religion priming words include neutral connotations (pew, parish), it does not promote prosocial behavior, but if it includes positive connotations (heaven, prayer),...