Interesting... I can't really see this being tied to IQ however general understanding of technology, as the uninformed would use whatever browser was on their machine and most accessible...
In a study that is likely to incite controversy, AptiQuant, a Vancouver, British Columbia based Psychometric Consulting company has released a report that it says shows users of Microsoft Internet Explorer have lower Intelligence Quotient’s (IQs) than do users of other internet browsers. The company is basing its claims on scores online users received when taking the online Wechsler Adult Intelligence Scale (IV) test.
The test results were collected from over 100,000 English speaking people from New Zealand, Australia, the UK, Canada and the United States, over a span of four weeks and the score results were compared with the browser used to reach the site offering the test, which were offered free to random users.
See the article HERE