Many scientific studies have analysed how ageing affects key human functions like memory, strength, vision and hearing.
Ageing can affect capacities such as vision and hearing
What follows are extracts from a Department of Trade and Industry research paper which has reviewed literature on the subject.
There have been a very large number of studies of the effect of ageing on capacity. The evidence from gerontologists, especially in laboratory tests, consistently finds that on average ageing reduces:
- lung capacity
- muscular strength
- bone structure
- speed of activity and reaction
Some other relationships with age are also well established. Anxiety generally increases with age.
In line with the findings from laboratory studies, there is evidence that work performance falls with age in jobs that make heavy demands on sensory perceptions, selective attention, working memory, and processing of new information, as well as in jobs requiring rapid reaction time and physical strength.
However, by no means all jobs fall into this category, and not all jobs with these characteristics show a deterioration in output with age.
Indeed, one of the challenges to researchers is to explain why the declines in physical and mental capacity which are well established in laboratory studies do not seem to result in markedly lower productivity in the workplace.
Three major reviews of a large number of studies on the relationship between work performance and age all come to the same clear conclusion: there is little or no relationship between the performance of older and prime age workers who are doing the same job. Those under 25 consistently tend to have lower productivity than both groups.
Drawing on more than 100 studies, Professor Peter Warr concluded that the average difference in performance is zero, and therefore that there is no evidence that the deterioration in capacity with age that is measured in the laboratory translates into lower levels of performance in the workplace.
Most jobs do not make use of full mental and physical capacity. Thus, even when some capacity is lost, work demands do not reach the threshold where performance is adversely affected. It is sometimes argued that many workers have to use more skills driving to work than they do in doing their jobs when they get there.
The evidence based on the perceptions of managers and colleagues as well as some independent studies by researchers measuring performance in the workplace also suggests that older workers:
- work harder and more effectively
- think before acting
- have better interpersonal skills
- work better in teams
- are less likely to leave
- have lower rates of absenteeism
- have better motivation
- have fewer accidents
- have more experience
- have better knowledge of the company and its products
Work is not just cognitive or physical. It requires skills in prioritisation, planning and troubleshooting, as well as motivation. These are all helped by experience.
Warr has developed a fourfold typology of jobs where the negative effects of ageing on capacity do and do not apply and where the positive effects of experience on performance is likely to apply or not.
Jobs in the age-impaired category are those such as racing driver or fighter pilot where continuous rapid data processing and reactions are required. Other jobs in this category are those involving physical strength such as coal mining or some aspects of construction.
Age-counteracted jobs are those where the positive effects of experience can offset reductions in speed or other capacity. These include a wide range of jobs, particularly skilled manual work.
For example, one of the studies reviewed by Warr found that older typists were slower to make each keystroke, but they processed larger pieces of text at a time, so had fewer pauses than younger workers, with the result that overall speed was the same.
The third group of jobs are those that are age-neutral: neither the deterioration of speed and capacity nor the increase in experience is relevant in job performance. Routine clerical jobs, retail cashiers or manufacturing operatives might be like this.
The fourth job type - age-enhanced jobs - includes those where neither speed nor physical capacity is a factor, but experience enhances performance. Jobs involving knowledge and judgement without time pressure, such as some senior management jobs or academic research would fall into this category.
What is worth noting is that in only one of the four job categories does performance decline with age. In the other three types, performance can be expected either to remain the same as someone ages, or to improve.
Across the economy as a whole, technological change is reducing the proportion of jobs involving heavy work and detailed concentration, both of which can be adversely affected by age.
Extracts from DTI Employment Relations Research Series no.18 - Retirement Ages in the UK: A Review of the Literature by Pamela Meadows