This should, hopefully, illustrate how just because two things appear to be correlated, does not mean they really are, nor that there is any sort of causal connection between the two. You can even look for your own correlations by clicking on the "Discover a new correlation" link. Just pick your starting category, then your first variable and finally your second variable. You can see how close is the correlation by looking at the number in parentheses. The closer to 1, the closer the correlation. The closer to -1, the closer to an inverse correlation. Then just click on "Correlate" to see your graph.