Fuji made this thing way too complicated
50% mensa members went to college
30% Americans went
More education means higher income fact.
Therefore mensa members should earn more than non mensa members.
Except that scatter plot up thread shows what's happening here, the low IQ side is getting shut out of school. As you get to a normal IQ and higher the effect declines. In other words, what are you going to say if it turns out 50% of Americans with an IQ over 100 went to college?
The link between IQ and academic performance is not in doubt, it's very well established, which is why IQ is used to extensively in learning contexts, especially primary education. The question is what is being measured. Is it really this
g factor, or is it measuring something more narrow, like skill at taking tests? In the latter case it's still quite a useful piece of data for, say, an educator to use to identify problem students and direct them to remediation. It does predict who will do well in school, prospects of attending college, etc., no matter whether it's just measuring "test taking skill", or intelligence. So it's a useful number.
But whether it translates into actual intelligence, whether it says anything about your ability to outsmart the next guy in a negotiation, say, or come up with innovative new product ideas, or figure out how to optimize business processes, or compose beautiful music, or whatever--whether it's linked to REAL intelligence is another thing.