I just found a nice article on the correlation between intelligence and atheism. There is a negative correlation between intelligence and atheism, which means as intelligence goes up, belief in a god goes down.
It also has some interesting things in it. It mentions how that over the past century or two, older generations did not have the abstract categorical and hypothetical thinking (ACH) as much as younger generations do now. They may have learned this type of thinking from education in school, from whatever science they had, but never needed to use it much, as life was more concerned with practicality.
One sociologist - P. Zuckerman, based on estimates from several international studies, deduced that there are "58 times as many atheists as there are Mormons, 41 times as many atheists as there are Jews, 35 times as many atheists as there are Sikhs, and twice as many atheists as there are Jews", atheism ain't rare.
Approximately 90% of studies ever conducted on this specific area have found the same results - the negative correlation of intelligence and belief in god, as I wrote before. This article also, from another resource, says that there is also a negative correlation with age and belief in god (as they get older, belief in a god decreases).
A series of studies by James Leuba in his works in the 20th century, he reported that "scientists were irreligious". But when these studies were replicated by Edward Larson and Larry Witham, the trend found has "reached its asymptote" at 7% - 7% of "elite scientists, such as those in the National Academy of Science" are believers in a god (whether they subscribe to an organised religion is not mentioned). This just shows the reduction, and my oh my, next time someone says scientists believe in god, they can take this mouthful
Anyway...studies were conducted in Russia in some "liberated" parts of the then Soviet Union, in illiterate communities. These communities actually NEVER used abstract categorical and hypothetical thinking (ACH), they were quite estranged to it and did not see it as useful.
Science encourages the development of ACH thinking, and then we become true skeptics, "not mere scoffers of the foibles of others". Science has an advantage over other forms of understanding when being questioned/critiqued by itself/own methods because it itself is based on ACH thinking, as opposed especially to "religious modes of thought".
The thing that ties this article all together is the Flynn Effect:
The Flynn effect describes an increase in the average intelligence quotient (IQ) test scores over generations (IQ gains over time). Similar improvements have been reported for other cognitions such as semantic and episodic memory.
From Wiki, which got their definition from another scholarly article I can't be bothered typing out.
Hope you all find this interesting! I have the link, but I don't think it will work for you guys because I only have access to the site cause I'm a student, ya know.
