This is a topic I read about and am curious about.
I have dyslexia and ADHD, two conditions which hugely impact the quality and quantity of my ability of focus.
The interesting thing about ADHD is not that it takes away from my ability to focus but that it often means I don’t control my focus, that directing my focus requires a significant amount of energy.
This article from the buffer blog is really good and gives a brief intro to my current line of thinking in the area.
The reason we work 8 hours a day, isn’t scientific or much thought out. It’s purely the a century old norm for running factories most efficiently.