It's hard to construct this without falling into the very trap I'm attempting to describe, but in my experience atheists and similar non-believers have a tendency not to make sweeping generalisations. Quite what that may say about intelligence I have no idea and less desire to speculate.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'