According to a report that has been much read and much discussed this week, working in a full-time job after you turn 40 is not good for your brain and can damage your ability to think.
The academic paper, from the Melbourne Institute of Applied Economic and Social Research, says that people who are past their 30s should work no more than 30 hours a week.
It also says that if you’re over 40 and work 60 hours a week your cognitive ability sinks lower than that of people who don’t work at all.
The study, which involved 3,000 men and 3,500 women, tested the ability of employees aged 40 or over to read words aloud, recite lists of numbers and match letters and numbers in a speed trial.
Its results have caused concern, not least because of their implications for companies hiring people over 40 and consequent human-resources policies. But Irish experts take issue with the findings, which they call sensationalist and overly generalised and which they say ignore key factors.
Maeve Houlihan, associate professor of organisational behaviour at UCD College of Business, says that there’s a “subtle sensationalism” in saying that the over-40s could be less productive when they work longer hours.
“The implication is that younger people cope with longer hours better. Let’s note, however, that those below 40 weren’t studied. No study can do everything, but I find the focus on quantity of hours worked, with no distinction of type of work, a bit limiting when talking about cognitive impact.
“Since we have no insight into the nature of the work or its cognitive demands, are we then talking about the social or reward stimulus of work? If type of work is not a factor, how can we distinguish these hours from other general activity, unpaid, voluntary, inside and outside the home?”
It’s a point taken up by Neil O’Brien, an occupational psychologist. “While it is true that the cognitive process will slow down as we age, to state that persons over 40 work best with a three-day week is generalising, and there are many other factors that need to be considered.”
Perhaps the biggest flaw is the study’s use of the blanket term “work”. The report implies that younger employees have better cognitive powers and can work productively for longer each week. But in some key areas of employment we actively look for more experienced people.
“There’s a problem of perception here,” says O’Brien. “If the study is stating that younger people have higher cognitive processes, then why do we look to older persons to take on positions of responsibility? For example, nervous air passengers would prefer a 40-plus pilot; for a life-or-death operation we would prefer a surgeon with decades of experience.
“Also, take world leaders: the vast majority of candidates for the US presidency are 60-plus, yet the role entails some of the most important decisions ever taken. If you accept this report then you would have to put President Obama on a three-day week.”
Tim Trimble, who’s assistant professor of applied psychology at Trinity College Dublin, also takes issue with how the study defines work.
“One of the range of key missing variables acknowledged in the report is that they don’t have any measure of quality of work. This may indicate that by age 40 many people are in jobs which are perhaps routine and which don’t challenge the incumbent.
“I am reminded of the research work of my colleague Prof Ian Robertson and others here at TCD in terms of cutting-edge techniques in enhancing and maintaining brain health in older populations, which essentially involves novel challenges to brain functioning, for example.”
Trimble adds that it’s “important for employers and managers to ensure proper job-person fit in terms of skills and motivation, and to maintain challenge and learning among workers in terms of things like continuing professional development and training.
“The authors mention stress as a key pathway which may impair cognitive functioning. Poor job-person fit increases stress in this context.”
According to Maeve Houlihan, “While statistical studies like this are useful provocations to get us thinking about public policy, stratifying by age, gender or any other demographic is not a good basis for managing people.
“Statistics are seductive, but each of us is individual. In terms of implications for HR policy, the most productive working arrangements, whatever your age and life stage, accommodate individual differences, needs and motivations and enable choice. The most progressive workplaces don’t fixate on hours worked but look at quality of outcomes.”
The problem with these and other reports into issues that potentially have major effects on our working lives rarely has to do with the studies themselves: they are invariably rigorous. Instead it lies in the way that media interpret the findings.
A look at the headlines this week would lead you to believe that if you’re over 40 you’re no longer fit for a full-time job. But all we can reasonably conclude from the report is that the particular people who took part replied to particular questions in a particular way. That data is open to a very wide range of interpretations.
Neil O’Brien says that there could well be another study next week that reports different results.
“For example, I could quote from a report done by the Association for Psychological Science which found that older employees perform more consistently, are just as productive and do not make serious errors in their work the way younger employees do.”
There is also the danger in defining people by age. Your aptitude for the job, your talent, your professionalism, your physical and mental wellbeing, your fitness and your diet: all of these and more are important considerations.
