I'm not addressing the claim of this article, just the methods. IQ has a misleading (and factually inaccurate) name. The Q stands for quotient, but an actual IQ is not a quotient at all. IQs are ordinal ONLY. They allow you (to the extent that IQ tests measure intelligence) to rank people, not assign numerical values. It is not possible from IQ scores to say "Alice is x% more intelligent than Bob", only "Alice is mor…
IQ tests aren't a great measure of plasticity in the first place - they're just the best thing we have to measure on a wide scale. Plasticity is a far more personal attribute. Many IQ tests just repeat the same problems, and a person can improve their score without really learning anything but how to take an IQ test.
Throw someone something entirely new and you may get real insight into their mental plasticity.