40 Hours is enough

40 Hours is Enough

We have this idea that the more we work, the more we accomplish. There’s simply no evidence to support it. The idea that working longer achieves more has been proven to be untrue. Let’s respect 40 hours as a solid week’s work – and let people find the right time to complete it.

Over the last few years we’ve filled much of the working day with new distractions: lots more emails and more meetings (since electronic calendars have made them easier to arrange). This has lead to many of us thinking that the answer is to work longer into the night.


Since the arrival of email on our phones our working days have got longer. Some estimates say that the average working day has increased by more than a quarter.


So what does the data say?


Research by John Pencavel at Stanford University suggested that the maximum that any of us should productively work is 50 hours a week. In his words “the marginal product of hours is a constant until the knot at [about 50] hours after which it declines”. Worse than that after 55 or 56 hours exhaustion kicks in and output starts decreasing.


In his data people who work 70 hours (10 hours a day, seven days a week) achieve almost the same as those who work 55 hours.


So what to do? Well we should recognise that probably being energised for 40 hours of good work is probably the best way to preserve our creativity and imagination.


One of the most important steps here is to change the people we idolise.

Charles Dickens wrote 15 novels, hundreds of short stories and edited a weekly magazine but he rarely worked into the afternoon. It’s well documented that Watson and Crick the discoverers of DNA did some of their thinking over a long lunch in the pub.


Our best output probably comes in intensive bursts of activity. If we start thinking about what we’re producing rather than the time it takes to do it, getting it done in 40 hours is the right thing to do.


The Solution


Try to stamp out passive presentism. Discourage anyone from commenting ‘half day’ when a colleague arrives or leaves outside ‘normal working hours’.


In ‘Work Sucks’ Jody Thompson and Cali Ressler refer to these comments as ‘sludge’. They say they cause untold stress for the recipients of them – who probably are already anxious that the scrutiny of their method of working as well as results of working seem to be under the spotlight.


The authors were responsible for creating The Results Only Work Environment – a method of changing our obsession with 40 hours a week. Adopted by companies like GAP and Best Buy it focuses on the outputs of work (not the inputs like working hours). Book /podcast


In The Way We’re Working Isn’t Working Tony Schwartz asks that we shift from a focus on longer working hours to an interest in managing our bursts of energy. Most people work in 90 minute energy cycles. Getting ourselves ready to maximise the output of each cycle is the best way to get the most from our work.


Further reading:

Evidence that working more than 55 hours could actually end up making you sick.

Working more than 50 hours a week makes you less productive.

Maybe 35 hours is the right amount.

Book: Daniel Levitin – The Organized Mind.

Book: Alex Soojung-Kim Pang – Rest 



In 2013 The Economist published an analysis of working hours and productivity. The trend backs up the research by John Pencavel – working longer doesn’t increase productivity, it reduces it.

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