[regularfry]

Depends on the distribution. And which average.

[umanwizard]

IQ is distributed normally.

[regularfry]

That's begging the question.

[umanwizard]

what do you mean?

[regularfry]

The definition of IQ says that it assumes a normal distribution, with half either side of the mean. To use the definition of IQ as a justification for the statement "half of all people have less than average intelligence" assumes that the distribution of intelligence matches the distribution of IQ.