Profile of a nation
Figure 7.1 shows the distribution of IQ scores across all participants. It is clear that the IQ scores from this sample follow the typical normal distribution curve
of the distribution of intelligence – that is, there are just as many participants above as there are below the average. The blip at the lower end is probably caused by a number of people who were under 18 years, for which the norms did not appropriately account (who probably called themselves ‘18 to 25-year-olds’), and because some viewers could have ‘faded out’ during the 2 hours of the test, and started to guess more towards the end – although this is somewhat ameliorated as they needed to finish the test before they could submit their answers (and the ratings showed no drop-off in viewers in the last hour of the testing).