lol how do you come up with these conclusions???
Logic, experiences and various studies.
Low level of education and low income often go in pair with higher religious devotion. Also a more traditional, "conservative" society is usually more religious and it's a fact that more modern and "open" societies and/or individuals are growing faster and are "smarter". People who want to understand things are more likely to be atheists. Willing to learn, live by cold facts and logic are attributes of being smart.
I'm not saying that Atheists are usually smarter by a huge margin and that all religious people come from lower socioeconomic backgrounds but that it's just more likely to happen because of various factors.
People from lower classes usually aren't as smart, confident or logic. They are more likely to be very traditional and more likely to believe in superstitions. They want something to rely on in their tough situation rather than be confident enough to believe that they can do something by themselves.
That's why poor countries have many more religious people. Religion is written in their traditions because their society is more hopeless than confident of their own actions. Societies where more individuals are well educated, more confident and logic tend to leave religion behind. People who don't need help of a super being, who are more confident that their own action will leave a desired reaction (or those who just know that it is that way) are more likely to question religions and become Atheists. Not to mention that they are also more keen on science which can answer and explain "the unknown" which leads people to be religious in the first place.
Not that all of these always happen but are just more likely, thus the word "usually".
http://www.webpages.uidaho.edu/~bdyre/psyc218/survey03/Gaede.pdf
Anti-Religious Forces: Specific Factors Fuelling Secularisation
http://www.matteidoganpersonal.com/admin/files/45/1205854558058789.PDF (not really on point but page 12 and the Dutch society is an example of a growing modern society leaving the Religion behind)
What Causes Religion and Superstitions?
There was also a thread with another study about IQ of atheists and religious people pointing to a bit higher average IQ of atheists. I don't believe that IQ is a valid measure of "smartness" but it does measure some areas attributed to intelligence.
I'm not an Atheist myself but all of these seems pretty obvious to me. You are more likely to meet a "backwards" religious person than a stupid atheist but both are likely. Just one is a bit more likely than another.
