I'm sure it is an important factor in how the brain works, and that the research is insightful. I'm having some trouble with the idea of extrapolating complex behaviours from what essentially is a micro-benchmark of cognition. That sounds overly reductionist to me.

Although I guess it is impressive to find consistent results within said micro-benchmark, of course, since that hints at something fundamental about our biology (in the reddit AMA linked elsewhere in the comment the author claims to see no difference for gender, educational background, etc; suggesting age is the main factor. That seems significant).

I would call this test an analogue of IQ testing. Again, we see how mainstream thought places IQ on a pedestal. Mainstream thinking overvalues and overrates mental gymnastics, such as performance on IQ testing. But learned experience is in my opinion far more valuable and should be valued more by mainstream thought. At age 60, it is true that I cannot perform as well on IQ tests. But in my opinion my understanding of the world is much greater. I was like a child at age 25, even though I tested well on IQ tests. But I was just a child. Does mainstream scholarship explore this facet of human development? Not much....

The question is whether the correlation stays strong, though. I can imagine this accurately measuring decline in complex functioning, but I can also imagine it being the correlation that weakens as you age. In the second case, it would just be a warning to compare same-age statistics when comparing between people.

I'm interested by the path of reasoning from evo-psych. The underlying mechanism may manifest in higher-order features like motivation. How this motivation is mediated by culture (both economic and social) might lead us to draw interesting connections with both pathology and maximising productivity.