You already know the answer.
A study from Keio University suggested people working 25-hour-weeks performed better in cognitive tests…
Over 6,000 Australians were studied. Participants were asked to do a number of cognitive tests; read words aloud, recite lists of numbers running backwards and link letters and numbers in a particular pattern under time pressure.
They found that people who worked about 25 hours a week (which works out roughly as three day week) tended to get the best scores. Those who did not work at all scored about 18 per cent lower on the reading test. Working 40 hours a week was linked to a slightly smaller cognitive deficit, but working 55 hours or more seemed to be worse than being retired or unemployed.
Part-time work, the report has concluded, is the perfect balance between brain stimulation and stress.
The French, despite working fewer hours, are more productive than the Brits.
The findings echo those of a celebrated study that has followed 10,000 middle-aged civil servants in Whitehall since 1985. One analysis of this data found that those who worked up to 55 hours a week also did worse in a series of cognitive tests than those who generally kept to 40 hours at most.
from the London Telegraph