Select Committee on Science and Technology Written Evidence

Memorandum by QinetiQ

  QinetiQ has undertaken considerable recent analysis of research data on the ageing process, specifically in the context of assessing the physical performance and potential of Service personnel as they age. We regard this research as having an important bearing on the population as a whole, and consequently on the Committee's area of inquiry. As a result of the studies, details of which are set out below, QinetiQ believes that further research is necessary in the following areas:

    —  The effects of ageing on the physical performance of women.

    —  Ageing and task performance, concentrated on those tasks involving heavy loads on working memory, selective attention, information processing and rapid reactions to presented material.

    —  How and why attitudes and motivation change in the work place with increasing age.


  The age structure of the European workforce is changing. The birth rate is falling, which means that from around 2011 onwards those in the age group 15-29 will represent a decreasing proportion of the population. By 2010, it is estimated that over 40 per cent of the working population will be aged 45 and over and by 2020 the modal value for working age will have increased from 35-39 to 50-54 years of age.

  In 2003 QinetiQ undertook a study to review the research evidence that related the physical, cognitive and non-cognitive (psychological) factors associated with the ageing process to performance of military or analogous tasks1. The study also attempted to identify gaps in our current knowledge and identify strategic research that should be undertaken.

  The approach adopted was to undertake separate reviews of the published literature on the effects of ageing on physical performance and the psychological effects of ageing on performance. This included the effects of ageing on cognitive performance, (ie thinking, decision making etc) and non-cognitive factors such as attitudes and motivation towards work.

Ageing and physical performance

  "Physical Fitness" encompasses a variety of diverse factors, but can be described generally in terms of four component parts: strength, speed, endurance and flexibility. These can be measured in different ways but the ability to utilise oxygen is commonly used as a measure of "fitness" as high levels of this "aerobic capacity" are necessary for speed and endurance. A measure, known as VO2max, (which is a measure of maximal aerobic power) is often regarded as the best indicator of general fitness.

  Maximal aerobic power reaches a peak level at around 20 years of age, then declines throughout the rest of life at a rate of around 1 per cent each year.

  However, this rate of decline can be reduced. Studies of endurance athletes have shown the effect of prolonged training on aerobic capacity well into later life. The decline appears to be more directly related to a reduction in the amount of training, rather than any factor directly related to the ageing process itself. Aerobic capacity appears related much more directly to activity levels than to age. The aerobic capacity of active individuals declines more slowly if they maintain a regular exercise programme. Sedentary individuals decline at a rapid rate during their 20s and 30s, followed by a slower rate of decline of their VO2max as they age further. It is likely that gradual increases in training levels could counteract the ageing process and allow an individual to maintain a constant level of aerobic fitness for many years.

  Peak muscle strength is generally achieved between the ages of 20-30 years. It deteriorates from around the age of 30, but is subject to an increase in the rate of deterioration towards later middle age. The cause of this progressive loss of strength is an age-related loss of muscle mass, at an average rate of 0.5 per cent per year. A fall of 25 per cent in peak isometric force is usually observed between 30-65 years, but much of this loss will occur after 55 years of age. However, evidence from industry of older workers suffering strength-related problems is limited. It appears that reduced muscle function with increased age is not inevitable, and that resistance training can improve muscle recruitment and maintain, or even increase, muscle mass throughout life.

  In 1999, the Research and Technology Organisation (RTO) of NATO held a symposium on the operational issues of ageing crewmembers, which investigated the case for a re-evaluation of age policies for military crewmembers and covered operational, psychological and physiological aspects2. Three significant conclusions were drawn:

    —  During these times of preventive medicine, health promotion and healthy lifestyles, physiological age of individuals appears to be more important than chronological age of groups;

    —  Knowledge, behaviour and experience seem to adequately compensate for ageing among crewmembers in military environments; and

    —  These factors, combined with new medical and surgical therapies, and technological advances (in equipment designs, etc) appear to justify seriously re-examining current age policies for military crewmembers.

Fitness and diversity

  Men and women appear not to differ, in most respects, in the ageing process. Generally, women have a lower aerobic capacity, but some of this difference is attributable to societal norms that are gradually being eroded. Muscular strength is less in women, but specific training can lessen this difference. Major differences between men and women appear in the mid-50s, when a marked fall in muscular strength has been reported in women, but not in men. It is possible that this is brought about by hormonal changes, but that other factors such as cultural expectations may heighten this deterioration. More work may be required in this area. This study found no reported differences in the response to the ageing process by populations of different ethnicity.

Maintaining fitness

  A study on the self-perception of fitness levels among fire-fighters showed no correlation between how fit personnel think they are and how fit they actually are. However, a supervised fitness programme restored aerobic capacity and strength levels in unfit fire fighters to the required levels, irrespective of age. A study of Finnish police officers showed that, whilst muscular strength declined over the 15 years of the study as the group aged, the absolute aerobic capacity of the officers remained constant. It concluded that the physical fitness of middle-aged police officers depended on the level of physical activity in young adulthood, and that age, in itself, was not related to reduced physical performance on the job. However, the sporadic nature of the high levels of physical performance associated with fire-fighting was shown to be insufficient to maintain a high enough training drive in itself (ie simply doing the job itself might not keep you fit enough to meet the demands it imposes).

  Studies that have looked at older groups show that the response to a training stimulus appears to be unrelated to age, and that significant increases in aerobic capacity, strength and flexibility can be achieved in people well past normal working age.

Ageing and cognition

  Psychologists generally consider two aspects of intelligence supported by experimental evidence: "fluid intelligence" and "crystallised intelligence". Fluid intelligence is held to be unaffected by experience (being largely determined by hereditary factors) and to depend on the integrity and efficiency of physiological and neurological functioning. Therefore, it is likely to be subject to decline from early adulthood onwards. Crystallised intelligence, in contrast, is a function of accumulated experience, knowledge and training, and is largely independent of fluid intelligence after early and middle adulthood. It can be expected to increase through adulthood into old age. Studies have shown that, on average, the older worker performs less well than their younger counterparts on tests of fluid intelligence. However, since the development of crystallised intelligence depends on the exercise of fluid intelligence, the rate of growth would be expected to diminish with age. Generally speaking, the pattern of susceptibility, or resistance, of intelligence sub-tests to the effects of ageing is in line with these hypotheses in that scores on sub-tests which appear to be primarily measuring crystallised intelligence are more stable with age than are sub-tests measuring fluid intelligence.

Specific cognitive abilities

  Laboratory studies have shown that ageing affects performance on many information-processing tasks. These include: memory for previously presented material, divided attention, working memory, dual-task activities, and rapid reaction to presented information. The decrease in performance has been attributed to impairment of working memory, reduced processing speed or a combination of both. Although these decrements are strongly correlated with age throughout adulthood, they become more apparent after the age of 50 years.

  Although early research suggests older workers have greater difficulty in learning new material, recent research has shown factors which can remove some or all of these difficulties so that there are little or no decrements associated with age. If the material to be learned is contextual, ie the environment supports the process, then older workers are just as adept at learning as their younger counterparts.

  Additionally, if the learning is implicit in the task, ie unconscious learning, then little or no age decrements are found. For example, in a task involving planning the best route between two points on a map, older workers will later recognise presented place-names, on that map, just as well as younger workers do. This might indicate that working memory decrements are not as extensive as first suggested.

  Many of the studies are open to criticism on methodological grounds. Although research has shown that the above decrements exist, they are quite small. Typically, the range of scores around the mode is much greater for older participants in this research than for younger participants. This means that any cited average score is less of an indication of any individual score among older people than among younger ones. That is, there is a large within group variation with, for example, many older people outperforming many younger ones.

  Another point of note is that, by the very nature of this area of study, the majority of studies are cross sectional (ie comparisons are made between separate groups of individuals of particular age groups), not longitudinal (repeated studies undertaken on the same group of individuals at different ages). Those studies that have been longitudinal have produced results that show a less marked decline in cognitive ability as one ages.

Non-laboratory studies

  If the measured outcomes of any test of cognition are actual work, or simulated work tasks, then age-related defects disappear. Although research into the cognitive effects of ageing goes back nearly 40 years, research upon how any age related cognitive decrements actually affect work performance has only begun in earnest within the last 10 years or so.

  Most of these studies show that within middle adulthood work performance is rarely affected by age. In fact, older workers often show higher performance levels than their younger colleagues. This is not a total surprise given that older workers tend to be more experienced and so have much more crystallised job knowledge than do younger workers. It is likely that the older worker uses their wealth of expertise to develop more efficient "routines" to overcome any cognitive deficits they may experience.

  Experience, usually measured by tenure, or length of service that is correlated with age, would be expected to counteract the effects of age on performance. Some studies of industrial and clerical jobs have shown that when length of service is controlled, age effects on performance disappear; conversely when age is controlled, the effects of experience remain. Experience is a stronger predictor of job performance than age.

  Research into how older workers cope with training is an area of concern for the recruitment of older people. If experience is the mediator of age-related cognitive deficits, employers need to know how commercially viable the training of inexperienced older workers is. A great deal is known about the training procedures most appropriate for and acceptable to older workers. For example, older workers only show reduced ability to learn if the pace of learning is forced. Older workers also take longer to complete training, although if more time is given to learn, they can achieve the same level of attainment as their younger counterparts. This time limited deficit is not strictly an age-dependent feature. If the training course is intensive or difficult, then younger workers can be just as likely to show achievement decrements in post-training tests. It may be that the perceived workload in training can affect the effectiveness of the training as older trainees may feel they have to invest a lot more effort into achieving an accepted standard.

Non-cognitive factors

  Research evidence in the field of personality and ageing is, at present, limited. Some studies suggest that older people score higher on scales of self-control, conscientiousness, tolerance, modesty, wellbeing and achievement via conformance, but lower on sociability, outgoingness, affiliativeness, extraversion, change orientation, conceptual thinking, and achieving via independence. Despite these findings, there is no evidence that any age differences within personality affect work performance.

  It is possible that, even if the underlying personality does not change, as individuals age they conform to an age norm or that they become the stereotypical older person. The notion of an age norm seems odd, as it suggests that individuals take on age as an identity or role. Yet research suggests that this happens.

  Research has identified both positive and negative stereotypes of older workers. Stereotypes can be overcome by direct experience with individual members of the group; however they guide initial behaviour and, thereby, shape subsequent interaction. Since it is a widely held stereotype that older workers are poor learners, they are less likely to gain access to training schemes and it is likely that the stereotype becomes a self-fulfilling prophecy.

  Recently, this notion of age norms has been questioned. While there is broad agreement as to expectations of career achievements by certain ages, there is no clear indication that these expectations affect behaviour. There is no indication of sanctions being applied if one does not conform to the supposed norm.

  However, like people at other stages in their lives, older people come to understand what is expected of them by looking for cues and role definitions provided by others. Age-related norms regarding matters such as when to retire may be general for a society or specific to an organisation. Such norms shape the way other employees, including supervisors, treat older workers and may lead to differences in the methods used to evaluate older and younger people and to the creation of "incentives" to retire. Despite stereotypes to the contrary, workers at midlife and beyond are capable of changing and adjusting to changes in their environments.


  1.  Differences within age groups, particularly older groups from middle adulthood to the sixth decade, are almost as great as those between younger and older groups. Therefore, generalising from mean performance levels for older groups could be misleading. The implication is that there will be older people who outperform those considerably younger and this is true for recruits as much as for job incumbents. Conversely, it is highly unlikely that there is a measure of physical performance, achievable by 30 year olds that will not be achievable by at least some people of twice this age.

  2.  Previously accepted age-related decrements in performance would appear to be related to lifestyle changes associated with ageing, rather than physical limitations.

  3.  It would be correct to state that ageing is associated with a decline in strength, endurance and reaction time. However, it appears that this is neither as steep as has been thought previously, nor as rooted in physiological origins as might be thought. Furthermore, as the majority of people—even those considered "fit" in comparison to their peers—are not achieving their maximal possible fitness level, there exists a reserve potential to utilise to counteract the ageing process.

  4.  Studies linking age and physical performance suggest that "Biological Age" rather than "Chronological Age" is a more satisfactory indicator of the ability to work at certain jobs.

  5.  Surprisingly, the age-related decline in physical fitness appears to be more related to expectation than to biology. As we age, we expect to be less fit, so we exercise less, worry less about weight gain, and attempt less demanding roles. This is culturally reinforced as others' perceptions of us get coloured by our age, so it becomes increasingly difficult to maintain the activity levels that would maintain the levels of fitness we had in our youth.

  6.  The evidence on physical performance suggests, for those already trained to the required standard, that with constant practice performance levels can be maintained to a fitness level of a VO2max figure of 45-50 ml/kg up to 55 years and beyond. Some research suggests that even for physically demanding jobs normal professional activity might not be sufficient to maintain peak fitness requirements and therefore additional supplementary training may be required. Research with older groups suggests that response to physical training appears unrelated to age. This would suggest that, with training, older groups but below 55, could still regain physical fitness levels. However, the appropriate training regimes required to maintain and re-gain physical standards for older groups is an area that needs further research.

  7.  This study supports the recent conclusion by the US Rand Corporation3 that "Age is a poor predictor of the decline of stamina, strength, reasoning and comprehension". Age has some effect on most, if not all human capacities, but our research indicates that age-deficits are not found to any significant degree until the sixth, seventh and eight decades. The studies examined suggest that for a typical working life (age 20 to 60 years), there is little evidence that older workers are incapable of performing equally well in most job situations, military and civil. Exceptions are likely to be related to some military jobs that require superior visual acuity, strength or reaction time.

  8.  Evidence from cognitive research shows that the results of laboratory studies do not hold in the work situation. There seem to be very few occupations that cannot be performed by job incumbents up to 55 years and beyond. Experience appears to compensate for what little performance decrement would be expected as a consequence of ageing. For some high level tasks, experience may be the most significant factor. A separate study into the relationship between length of service and experience being undertaken by QinetiQ as part of the MoD's Corporate Research Programme will be of relevance to this question.

  9.  However, for tasks that involve heavy loads on working memory, selective attention information processing and rapid reactions to presented materials, performance decrements might be much more susceptible to the effects of ageing.

  10.  In terms of physical and cognitive performance there appears to be no biological reason why most people should not perform effectively in a wide range of occupations, at least up until the sixth decade. The evidence from the research on non-cognitive factors indicates that evidence for personality changes as a result of ageing is flawed through the lack of longitudinal studies. There is no evidence that if personality changes that it has an influence on work performance. However, everyday observation suggests that behaviour appears to change with age.

  11.  Stereotypes of the older worker exist, some positive and some negative. Little evidence exists as to the validity of these assumptions. The concept of a norm has been suggested and there is some evidence that older people adopt behaviour congruent with expectations. It is also possible that some stereotypes become self-fulfilling. If the expectation is that older workers are more difficult to train then they may be offered fewer training opportunities. How expectations and motivation of the older working population are shaped and change over time is an area that requires substantial additional research. With recent political comment concerning the need to increase the age of retirement for economic reasons, this would appear long overdue.


  1  Elshaw C,Kelm DM, Traynor ML Ageing and Military performance: Final Report. QinetiQ/KI/CHS/CR031826 June 2003.

  2  RTO meeting Proceedings 33 (papers presented at the RTO Human Factors and Medicine Panel (HFM) Symposium, Toulon, France, 11-14 October 1999). RTO-MP-33.

  3  Goldich R L (1995). Military retirement and personnel management: Should active duty careers be lengthened? CRS Report for Congress. US Library of Congress.

October 2004

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