A group of Australian scientists published a study looking at cognitive ability and the effects the number of hours have on it in the work week. According to their research, for up to 25 hours a week, cognitive function was improved by working more. However, after that increasing, working hours begin to have a negative impact on cognition.
But wait, before you go lobbying for a three-day work week, the research only studied Australians over the age of 40.
“In the middle and older age, working part-time could be effective in maintaining cognitive ability,” the authors conclude. “Our study highlights that too much work can have adverse effects on cognitive functioning.”
The researchers analyzed the work habits and brain tests of about 3,000 men and 3,500 women aged over 40 in Australia. Data was drawn from the Household, Income and Labor Dynamics in Australia survey and three measures of cognitive ability. It looks at people’s economic and subjective well-being, family structures, and employment.
Cognitive skills peak at around the 25-hour mark – for both men and women. This initially declines gradually, until there’s a steep drop as working hours become much longer.
“Work can be a double edged sword, in that it can stimulate brain activity,” the report said. “But at the same time, long working hours and certain types of tasks can cause fatigue and stress which potentially damage cognitive functions.”
The study did only assess over-40s, so whether they are any different from the rest of the population is not clear. Equally, the gradual decline indicates that longer working hours up to a point are possible, without significant impact on performance.
The figures also suggest that the cognitive ability of those working about 60 hours a week can be lower than those who are not employed.
The researchers said their findings needed to be taken into consideration as many countries raise their retirement age.