It appears that, on average, Opera users are near-geniuses, while IE tends to be used by users that have average intelligence at best.
AptiQuant said that it surveyed 101,326 individuals who were given online IQ tests. Surprisingly, the scores of the users appeared to directly relate to the browser they used. According to the results, intelligent users appear to have shifted away from IE6 and IE7 over the past five years and while we can guess that users with lower IQ levels are less likely to switch or upgrade web browsers, it is interesting to see that IE8 and IE9 users have a lower average IQ than IE6 and IE7 users had five years ago.
All other browsers apparently attract more intelligent users: Firefox is at 109, Chrome at 112, and Safari at 113. IE with Chrome Frame breaks through the 120 mark (123), Camino users score 126 and Opera users 128. AptiQuant said that only browsers with more than 500 users were considered for the overall result. So, are IE users, in general, dumb? It is nearly impossible to draw such a conclusion as the circumstances of the test are unknown.
However, the difference between Opera users and IE6 users is quite stunning and cannot be explained with a rounding error. While IE9 appears to have still a low score (which does not paint a great picture for Windows 7 users either), IE6 and IE7 are the problem areas for Microsoft's Internet Explorer, which may hint to more problems for Microsoft to find enough and the right incentives for those users to upgrade their browsers.