That's over 40 vs white collar. This study was just comparing people who worked 40 vs 25.
There's a lot more studies showing that working 60 vs 40 is bad for you cognition, but this one is unique in showing the same effects at a much loader working load.
There's a lot more studies showing that working 60 vs 40 is bad for you cognition, but this one is unique in showing the same effects at a much loader working load.