There have been quite a few studies over the years into personality differences between the religious and non-religious. They tend to use the well-known "Five-factor" model of personality, and they typically find that religious people are more likely to say they are agreeable and conscientiousness.
But these studies are mostly done on Western Christians. And anyway, there are other models of personality, ones which probably are more valid in non-Western cultures.
Naser Aghababaei, at the University of Tehran (in Iran), along with Jason Wasserman and Drew Nannini at the University of Kansas (USA), used the HEXACO model to study the personalities of 156 American and 165 Iranian university students.
The HEXACO model is basically the same as the five-factor model (emotionality, extraversion, agreeableness, conscientiousness, openness), but it includes an extra personality factor (Honesty-Humility) which relates to sincerity, fairness, greed avoidance, and modesty.
So, they got these undergrads to fill in the personality questionnaires and also to rate how religious they were (rating statements such as "I try hard to live my life according to my religious beliefs" and "I enjoy reading about my spirituality and/or my religion").
The Iranians and Americans had similar personalities overall, except that the Iranians reported significantly less emotionality (although this was because there were fewer women in the Iranian sample) and conscientiousness.
Once they adjusted the results to take into account the different proportions of women, they found that religion was linked to similar personality traits in both the USA and Iran.
In particular, religious people scored significantly higher in Honesty-Humility, and lower in openness, in both locations. They were also more agreeable and extroverted, although this was a little less clear cut since it wasn't quite statistically significant in the Americans.
However, in America religiosity was correlated with conscientiousness, while in Iran it was not. And in America, there was a hint of a connection between emotionality and religion, although again this was absent in Iran.
Now, this was self-reported personality, so we don't know if there was some self-flattery going on here. And it didn't compare religious with atheists, but rather dutiful religious with the, ahem, less so. And of course these were students, not real people.
But even so, it's fascinating to see that religion in both nations was linked to similar personalities. At the very least, it shows that religious people conceive of themselves in similar ways in both places.
However, it does seem to show that the idea that conscientiousness is characteristic of religion may be a Western conception.
And it's interesting that the link to agreeableness was less strong among Americans than among Iranians. Based on other studies, the link seems to be weaker still in Europe. Which suggests that, as religion becomes less important, being religious is more and more a characteristic of disagreeable people.
Or, alternatively, while those few people who are atheists in religious countries are also pretty disagreeable (i.e. argumentative), that's less the case when non-religion becomes more normal!
Aghababaei, N., Wasserman, J., & Nannini, D. (2012). The religious person revisited: cross-cultural evidence from the HEXACO model of personality structure Mental Health, Religion & Culture, 1-6 DOI: 10.1080/13674676.2012.737771
This article by Tom Rees was first published on Epiphenom. It is licensed under Creative Commons.