I'm fully aware of the peer-reviewed studies that you mention. The correlations they find are highly statistically significant, but the correlations are fairly weak. For instance one study found a 5.83 point gap between the IQs of atheists and dogmatically religious people. That is significant over a large population, but not for individuals. And our society has so many more dogmatically religious people than atheists that there is no problem in finding lots of very intelligent, dogmatically religious people.

Also the cause of that is far from established. For instance religious belief and ethnic background are strongly correlated, and ethnic background is more strongly correlated with IQ than IQ is with religious belief. How much of an effect does this have? It is hard to quantify.

Therefore I wouldn't put much weight on those studies. Don't pat yourself on the back too much for being an atheist, because it doesn't say much either way for your intelligence.

(Disclaimer. I am an atheist. But I know plenty of people who are much more intelligent than me who are strongly religious.)