I think the average person can understand these kinds of things, but won't because of lack of desire to learn and poor education (both at school and from their family), not because of inherent IQ problems.
The reason in third world countries people seem less smart is more likely to be because of poor education than poor IQ, and in theory IQ is your genetically gifted intelligence so education doesn't affect that.
Now if by IQ you just mean intelligence in general, then I would agree that it is as important if not more important than EQ.