Actually, Gareth, the traditional IQ tests like the Wechsler and Binet tests were standardized with an assumption of a bell curve, such that the mean, median, and mode would be the same.

In actuality, of course, IQ distibutions vary from the theoretical, but they do approximate a normal distribution and roughly half do fall below the mean.

Of course, when I read articles about IQs of famous people, I usually find one important fact missing, namely, how the IQ was measured.

Dr. J