We all know at least some people who are very good at IQ-like tests, math, science, etc., but who are complete idiots with respect to the real world. And vice versa -- people who are very wise about real-world matters (making deals, interacting with people, knowing how some decision is likely to pan out in the real world) but who would do poorly on IQ-like tests.
For this reason, I think of "smartness" as being at least 2 numbers.
Like Dungeons and Dragons characters who have two stats for "smartness": INT (for "intelligence") and WIS (for "wisdom").
The writer Nassim Taleb also coined the term "Intellectual Yet Idiot" (or "IYI") about this situation.
IQ-like tests measure INT. They do not measure WIS.
Every time a person who has high IQ, or is good at math, science, or articulate speaking, feels that some policy would be great -- but you know the policy would be a disaster because of how the policy's incentives would fully play out in the real world, among real people, you are seeing an Intellectual Yet Idiot in action.