Not to mention any faith or belief you may still have about people and average intelligence. Pick any article on CNN.com and then scroll to the end and read as many comments as you have the stomach for. Now ask yourself if your blood pressure rose, or if you just had a good laugh. This test works for me every time.
I do have to admit it has lowered all my expectations of the human race. Which is very positive in itself, since I will rarely be disappointed in anyone.