A friend posted the Internet Explorer users ‘have below-average IQ’ story on Google+. On the one hand, I love the idea of bashing IE users as incapable computer users who ought to get off the Internet. But then my Psychology background screams at this study as generally worthless. The lack of a statistical analysis ought to be another huge red flag.
I generally think an overall WAIS-IV score is mostly meaningless for something like this. IQ is a measure of skills. The typical use of intelligence is capacity instead. The skill set scores of WAIS like Similarities, Block Design, Sequencing, or Coding would at least indicate where are the differences and give better meaning. My favorite part of What is Intelligence? covered which of these are improving and possibly why.
Age is an obvious factor for which they should have controlled. It was even data they collected. The Flynn Effect demonstrates there are IQ changes over time. If the rumors are true that older Internet users are the most likely to use a default web browser, then that could be a very important factor muddling these results. Correcting for age might dramatically change these results.
Location could also be very important. A work computer might be locked down so the user is not taking the test on their preferred browser.