I think this may be true. When I was about 18, me and my brother did some tests from a book called 'Know Your Own IQ' by Eysenck. Frustratingly, I kept on getting 123 while my brother scored about 132. In the last one I actually scored 116, but my brain was obviously tired by then. Several years later when Mensa were running a campaign in the papers, I went along for a test and scored 156, which was enough to get me in. Sadly, I'd like to be that clever, but I don't think I am. Looking at how well I did at my A levels and how successful I was at work, I think 123 is more realistic. Considering how well my brother did at his A levels, university and career, I think 132 was realistic for him too. Despends what the statistical distribution is I suppose.