Hoax? I don't know. I'd say Internet Explorer is a dumb choice!
My guess is that Micro$oft might be doing some damage control in order to bolster the self-esteem of its customers!!!
A report claiming Internet Explorer users scored lower on IQ tests than users of other Web browsers turns out to have been an elaborate hoax. The report, supposedly based on a survey of 100,000 Internet users, was released last week by what appeared to be a Vancouver-based, Web-consulting firm called Aptiquant. Major news outlets -- including CNN, the BBC, NPR, CNET, Forbes and London's Daily Mail and Telegraph -- reported the story last week, as did multiple technology blogs.
LINK: http://www.cnn.com/2011/TECH/web/08/03/explorer.report.faked/index.html