content: I'm not sure about those exact numbers, but yep. It has to do with not only decreased productivity (checking emails, answering texts, etc) but the number of mistakes made that then have to be corrected, which is negative productivity. People think the 40 hour work week was developed for the benefit of employees, but it was created by employers who figured out that's the most amount of work you can wring out of a person before they start being less profitable. But that was for physical labor, mental faculties are even more prone to burnout at around 20-30 hours.