[westicle]

I'm mostly amazed at the low average IQ in the bottom scoring countries.

My understanding is that having an IQ score below 70 has historically been the definition of mental retardation.

Intuitively I feel there must be some severe cultural bias present in this data (or what it measures). The alternative explanation being that most of the population of Africa would be, on average, mentally retarded...

Maybe someone with a better grasp of statistics (or IQ tests) can clarify?

[antihero]

Perhaps it's because IQ has it's own fair share of problems and focuses on specific types of intelligence. It also has massive cultural bias.

Some would go as far to say it's entirely meaningless.