Working part-time keeps brains more stimulated than working over 40 hours a week, a new study shows.
Research, which analysed the work habits and brain test results of approximately 3,000 men and 3,500 women aged over 40 in Australia, found that working 25 hours a week benefits cognitive function, and helps in avoiding exhaustion and stress.
Participants were asked to read words aloud, recite lists of numbers backwards and to match letters and numbers under time pressure.
Overall, those who worked 25 hours a week tended to achieve the best scores.
Economic and subjective well being, family structures, and employment were taken into consideration.
The findings form part of the Household, Income and Labour Dynamics in Australia survey, conducted by the Melbourne Institute of Applied Economics and Social Research at the University of Melbourne.
"Work can be a double-edged sword, in that it can stimulate brain activity, but at the same time, long working hours and certain types of tasks can cause fatigue and stress which potentially damage cognitive functions," the report said.
Colin McKenzie, Professor of Economics at Keio University who took part in the research, said the findings indicated working extremely long hours was more damaging to brain function than not working at all.
According to the figures, the cognitive ability of those working about 60 hours a week can be lower than results from those who are unemployed.
However, Geraint Johnes, Professor of Economics at Lancaster University Management School, said: "The research looks only at over-40s, and so cannot make the claim that over-40s are different from any other workers.
"What the authors find is that cognitive functioning improves up to the point at which workers work 25 hours a week and declines thereafter.
"Actually, at first the decline is very marginal, and there is not much of an effect as working hours rise to 35 hours per week. Beyond 40 hours per week, the decline is much more rapid."
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