Education does not explain the link between atheism and liberalism: At Secular Right, I posted the GSS finding that atheists are about 5 times more likely to be extremely liberal than theists. A commenter asked if the correlation might be due to some other factor. I regressed political views on belief in God and got this:
Unstandardized OLS regression coefficients (N = 12,516)
Belief in God .209**
And when I add level of education:
Belief in God .205**
Level of education -.011**
**p < .01
The belief in God coefficient is reduced very little by the inclusion of education, so the connection between atheism and liberalism is not due to higher levels of education.
And I don't even need to look at IQ (although I did) because IQ is unrelated to political orientation.
UPDATE: Trust in science explains more:
Belief in God .168**
Trust in science -.164**