See ADDENDUM (8-3-11; 9:13am EDT) below
Over a period of around four weeks, the company gave a Wechsler Adult Intelligence Scale (WAIS) to users looking for free online IQ assessment tests, then recorded the results and browsers used for all participants above the age of 16.
Across the board, the average IQ scores presented for users of Internet Explorer versions 6 through 9 were all lower than the IQ scores recorded for Firefox, Chrome, Safari, Camino, and Opera users.
Furthermore, AptiQuant notes:
In addition, the results were compared to a previous unreleased study of a similar nature undertaken in 2006. The average IQ score of the individuals using the then-current version of IE was significantly higher than the individuals using the current version of IE now, implying that a lot of people with higher IQ are moving away from IE to other browsers.
There is of course much to quarrel with in such a study. Also: remember that IE is a Windows browser, so we are not talking about the Mac universe. As someone who used to use IE, I have to wonder: maybe it isn’t that less-smart people choose IE but that using IE is so frustrating that it robs people of IQ points?
This also reminds me of the research from a few years back about the socioeconomic level of MySpace users versus Facebook users — a finding that gets more and more interesting in retrospect.
(HT: Eric M. Jones)
ADDENDUM: It appears this study may have been a hoax.