No test measures intelligence. A test only measures you relative to the persons that wrote the test. – loosely quoting Asimov.
2007 is ancient history now. It is an interesting graph that one might correlate with a lack of meritocratic structure in society, but I’m on the low end cause I say this without looking up and reading the study. Pretty pictures evoke emotional blabbering bias and all that.
The core problem here is that “intelligence” as a single thing doesn’t exist, it’s like trying to measure someone’s fitness by just looking at their sprints and deadlifts. People can be good at some things and bad at some things, and even if you’re above average at all the measurable things that doesn’t really matter much if you’re an asshole who no one wants to hire onto their sports team.
IQ is fine as a mesaure of your general performance at some specific cognitive tasks, but for various reasons people basically always ignore that and just treat it like a number that magically summarizes how objectively good your brain is…