But, here's what interests me at the moment:
There is a known inversly non-linear correlation between the IQ of children and the religiosity of their parents (the more religious you are, the less smart your kid will likely be).
I am intensely religious and both my parents are as well. My dad is a fundamentalist minister and my mother is a less-than fundamental Christian. I, as you may or may not know, believe in Hasidic Orthodox Judaism (which tends to be very fundamentalist in nature).
That being said, My dad has an IQ of 189, I have an IQ of 140, and I do not know my mother's IQ.
I highly highly doubt that religiosity has anything to do with your IQ. The level of religious devotion has nothing to do with intelligence so far as what ones believes religiously.
There is a non-linear correlation between religiosity and social patholgoy (murder, rape, theft...).
In the US, the prison populations are per capita much more christian than the general public.
There is a very big problem with statistics. A lot of statistics agencies (when it comes to religion) will base their results off of the mere claim of religiosity. This is problematic for a number reasons. For one, claiming to believe in a religion does not make one a religious person. A person can think they are following a particular religion because they base their practice on misconceptions and popular myth. A person can also lie about their religion.
This fact alone can severely influence the accuracy of results when it comes to statistics and religion.
Another problem with your "fact" about prison populations is that it doesn't necessarily mean anything. The study cannot include facts about people who did not get caught for crimes they committed. It probably doesn't include facts about people who were wrongly convicted (something that happens a LOT in our justice system).
My experience has taught me that people who commit crimes come from all walks of life and religious beliefs.
As an aspiring linguist, I have learned that a vast majority of crimes, confusion, contention, despair, and misunderstanding come from communication error. I doubt that religiosity has much to do with how people behave (most religions teach generally humanistic principles). If anything, I'd say the majority of problems (whether related to religion or not) are the result of miscommunication.
I was raised in a catholic family and from the time I was a kid I thought it was ridiculous. What is it about religion that is so appealing to some people?
I cannot speak for everyone, but for me religion allows for a sense of purpose that I find reasonable. It provides a structured methodology for the achievement of goals that I agree with.
My particular religion, Judaism, is primarily concerned with making this world a better place. That, so I believe, is the most important goal a person can aspire to. Judaism also provides (what I consider to be) a wise methodology for the achievement of that goal.
Is it possible that I could believe in the practical humanistic parts of Judaism without belief in a God or any of the other fantastical ideas that are found within Judaism? Sure. But that would make life dull and un-interesting. Ultimately, it will not hurt anyone if I do believe in those things.