This finding holds even for highly motivated workers.
In the early days of World War II in England, patriotic fervor reached a peak.Dangerously low in supplies and equipment,
the nation was fighting for survival
The government extended the work week in defense plants from 56 to 69 1/2 hours
At first, productivity increased 10%, but it soon fell 12% below the previous level.
Other consequences of increasing nominal working hours included greater absenteeism and more frequent accidents In the 69 1/2-hour workweek, actual working hours were only 51.