Liberalism, Atheism, and IQ

I'm not sure exactly what to make of this story that reports:

Evolutionary psychologist Satoshi Kanazawa at the the London School of Economics and Political Science correlated data on these behaviors with IQ from a large national U.S. sample and found that, on average, people who identified as liberal and atheist had higher IQs.

I suppose we can insert a snarky comment here, depending on our particular ideological viewpoint.  The differences, while not huge, were statistically significant -- meaning large enough to suggest they're real and not by chance.

So how does the causality work here?  Does being liberal or an atheist make you smarter, or vice versa?  According to the story:

these preferences may stem from a desire to show superiority or elitism, which also has to do with IQ. In fact, aligning oneself with "unconventional" philosophies such as liberalism or atheism may be "ways to communicate to everyone that you're pretty smart," he said.

So higher IQ folks might be drawn to beliefs that set them apart and signal that, ahem, they're smart.

Data for the study came from this big health study and from the General Social Survey, which is a huge and useful dataset that I've used myself.

And there's sorta good news if you're a meat eater like me.  According to the story, vegetarianism is often linked to intelligence in other research, but this study found no association with IQ.  Whew!  But the evolutionary idea remains the same, goes the reasoning.  Vegans may in general show some higher intelligence because smarter people like to demonstrate superiority -- thus eating their veggies and skipping their burgers.