If you use Internet Explorer, your IQ might be below average–at least, according to one study.

AptiQuant, a “psychometric consulting” firm that provides hiring exams for businesses, gave online IQ tests to more than 100,000 people. Visitors arrived either through organic searches or through advertisements on other sites, and Aptiquant made a note of which browser each test taker was using.

On average, Internet Explorer users fared the worst, with IE6 users at the bottom of the pile and IE8 users performing slightly better. Firefox, Chrome and Safari fell in the middle with little difference between them. IE with Chrome Frame and Camino landed on top, along with Opera, whose users scored the highest (on average).

“The study showed a substantial relationship between an individual’s cognitive ability and their choice of web browser,” AptiQuant concluded. “From the test results, it is a clear indication that individuals on the lower side of the IQ scale tend to resist a change/upgrade of their browsers.”

Now, you might argue that Internet Explorer’s standing as the most popular Web browser means more IE users took the test, pushing their scores toward the mean. But AptiQuant also provided data from a similar 2006 study showing that Internet Explorer users performed well — back when IE had a bigger share of the market — so that theory may not hold up. It’s also possible, as Business Insider’s Matt Rosoff points out, that computer geeks with high IQs are more likely to use other browsers, but again the 2006 study doesn’t bear that theory out.

Whatever the reason for these results, I wouldn’t take them too seriously. They are, after all, comprised only of people who feel compelled to take IQ tests. But if you ever want to argue that Internet Explorer 6 users are too stupid to upgrade, at least now you’ve got some empirical evidence.