>...Psychologist J. Philippe Rushton of the University of Western Ontario says the research was prompted by earlier studies in Britain and Denmark that reported a 4- to 5-point IQ advantage for men, based on assessments of general intelligence. "My colleague, Douglas Jackson, and I decided that we really needed to confirm [the findings of] these other two psychologists, and we confirmed them," he said....
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>http://cosmiclog.msnbc.msn.com/archive/2006/09/07/3075.aspx?Ajax_CallBack=true
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>hehe. I knew that already...

If you read the book suggested by Tamar Granor in
Re: Questions for interviewee Thread #1038399 Message #1038482 you'll see, that the gender difference may be explained by the way the tests are made.