Just look at carpenters. There is way, way more math involved in carpentry than sales managing, but the data they are showing indicate a lower range of IQ's for carpenters than sales managers. They actually show carpenters to have the lowest average IQs of all the trades, but they do more math than most trades.
And more importantly, there was only one group where the 50th percentile of that group fell more than on standard deviation above the mean for IQ. Statistically speaking, we're not talking about the difference between intelligent and unintelligent, we're talking about the difference between the lower end of average and the upper end of average average.
And medical doctor was the only field that didn't seem to have sub-100 IQ scores associated with it. Further supporting my claim that being good at math =/= intelligent.
Also I'm sure you understand that correlation =/= causation. You fail to take note of any possible confounds. For example, the jobs aren't really ordered according to math skills nearly as much as they are ordered by the amount of physical labor associated with them. The more physical the job is, the lower the average IQ for the job. Is this because people with low IQ's can't get the less physical jobs? Of course not, there's tons of evidence right there showing that people in those jobs can have low IQs as well.
Could it be that people with lower IQ's tend to prefer physical jobs while people with high IQ's prefer less physical jobs? Actually, that's very possible.
I'd say that we should really control for such variables before we make claims like skills in mathematics go "hand in hand" with a pretty good IQ. I'd say that someone with a high IQ is more likely to be good at math than a person with a low IQ, but that's nowhere near a guarantee.
Democracy is designed to be decided by the people and , unfortunately, the people are generally stupid, or at best, average.Let's get back to the debate now that started this. However you want to filter (education, IQ test, etc.), those voting on something should have a sufficient understanding of it by some standard.