The headline sounds like a punch to the gut: the first generation “less intelligent” than their parents. It’s the kind of claim that instantly lights up timelines because it feels like it explains everything people already worry about — attention spans, screens, classrooms, the constant noise of modern life.

But the real story is more complicated, and honestly more unsettling, because it’s not about “people getting dumber” in a simple, genetic way. It’s about measurable changes in test performance that, in some countries and some cohorts, appear to be moving in the wrong direction after a century-long rise known as the Flynn effect — and researchers think the reasons are environmental, not inherited.

One of the most widely discussed pieces of research comes out of Norway, where researchers analyzed a massive dataset of cognitive test scores from military conscription records. In that work, IQ scores rose for cohorts born in the 1960s and early 1970s, then began to fall among those born after the mid-1970s — and the drop showed up even within families, which is a big reason the authors argued environment was the driver rather than genetics.

If you want the straight-from-the-source paper, it’s here in the official record at the published PNAS study with the details and methods laid out, and the key point is that it’s not a moral panic or a vibes-based claim. It’s an attempt to explain a reversal pattern that shows up in the data, and the authors emphasize that something in the world people are growing up in seems to have changed.