Studies of outstanding achievements show that innate or “natural” ability is a crucial entry qualification for a distinguished career playing music 1 or chess 2 but that most of the vast differences in achievement between excellent and internationally outstanding players are due to tens of thousands of hours of deliberate practice over decades.
This distinction between “natural” and “acquired” abilities applies to species as well as individuals. It took Newton and Leibniz, two of the most creative mathematicians who ever lived, years of effort to invent the calculus, but this has become part of our common intellectual heritage so that schoolboys now master it in a few weeks. As we grow older we sadly find that unfamiliar problems are becoming harder to solve and new skills take longer to learn. On the other hand longer life brings a larger repertoire of useful information and learned skills. We must suppose that we shall reach our lifetime peak performance on the things that we do best, most often and most enjoy when the trade-off begins to work against us and we start to lose old abilities faster than we gain new ones.
A different issue is that retaining useful skills and information is one thing and deploying them is another. Additional years of practice preserve, and even increase our vocabularies but this does not mean that we continue to use words as dexterously as ever. Susan Kemper 3 analysed a remarkable collection of diaries preserved by an enlightened public library system in Kansas. Many covered 40 or 50 years of their authors’ lives. Sue found that diarists’ vocabularies only slightly reduced as they aged but their writing styles became less varied and flexible. As young adults they often used long and complex sentences and deftly handled multiply embedded subordinate clauses but, in old age their sentences became much shorter and simpler. To use complicated grammatical constructions we require an efficient working memory. When we have to hold a tortuously unwinding sentence in mind until we reach a word that, retrospectively, makes sense of the rest. (Recall the legendary simultaneous translator who screamed during a particularly long and tortuous German sentence – “a Verb,…a Verb…For God’s Sweet Sake give me a verb.”). Keeping and increasing our stock of words is one thing, but keeping the computational efficiency that allows us to assemble them into the most appropriate and meaningful orders is another.
One way to find out when our combined assets of declining innate “smarts” and improving learned skills bring us to our personal peaks is to track lifetime career paths of outstanding individuals. A study of 43 financial experts aged from 24 to 59 found that while the older now had slightly lower intelligence test scores than their juniors their longer experience compensated for this in work-related decisions 4. A similar study included a questionnaire of “tacit”, often unexpressed and un-documented, knowledge relating to their work and found that more experienced older managers still performed well on this5.
During the 1930’s and 1940’s H. C. Lehman compared the ages at which outstanding figures in mathematics, science, literature, and history6, the visual arts7 and music8 made their greatest contributions.
Mathematicians, physicists and chemists peaked in their twenties and thirties, historians and philosophers in their forties and fifties, novelists and essayists in their twenties and thirties, but more often in their forties and fifties and sometimes even in their sixties and seventies. Interestingly, poets tended to peak in their thirties, much earlier than novelists and other literary figures. Graphic artists, such as Titian could still produce remarkable work in their seventies or even their eighties, as could musicians, particularly executants such as Pablo Casals. One interpretation might be that great new discoveries in mathematics and science depend on original and innovative thought and are not necessarily derived from very wide and detailed knowledge of a field. In contrast, in history and literature years of study are necessary to master huge bodies of information before original new interpretations become possible. We know from studies of outstanding pianists, and chess players that exceptional skill requires long, continuous and deliberate practice1,2 .This is probably also true for writing, painting, etching and sculpture.
It is not surprising that even the most able of us become less productive as we grow old because we all eventually die and will probably not be at our intellectual best for some while before this event. A study of correspondence by eminent literary figures found, perhaps unsurprisingly, that the quality of their writing began to wane up to ten years before they died 9 A different way in which mortality statistics may affect surveys of career trajectories (or vice-versa!) is suggested by a disconcerting report that 2102 exceptionally creative or “versatile” literary figures and scientists died, on average, from 2.7 to 8.2 years before their less high-achieving peers 10. I know of no convincing explanation for this apparently well-documented fact but, if the good indeed die young, this would certainly nudge statistical counts to favour an “early achievement” hypothesis.
It is hard to interpret evidence that age and terminal pathologies affect some kinds of mental skills such as mathematics, hard science and poetry earlier than others such as philosophy, painting and music. For example, there is the difference between a person’s age when she first has a remarkable new insight and when she eventually gets round to publishing it, perhaps after many years of analysis and checking. Many authors and philosophers have spent decades revising their major works. Perhaps achievements in the humanities are less immediately based on competition of ideas than in science because they do not require accepted theories to be challenged and refuted before they are replaced. In science there has always been fierce competition to be the first to solve problems that have long been identified as crucial goals for research and solutions are triumphantly published as soon as they are found. In literature, people compete in different ways and usually not against such severe time pressures.
Lehman pointed out that his data were not ideal because some of the careers he studied were during the nineteenth and even the eighteenth century when early deaths brutally curtailed productivity. Even in the young and middle aged, illnesses ending in death accelerate trajectories of cognitive decline, even over periods of eight to eleven years. Contrasts are only valid if they are based on the entire careers of equally long-lived geniuses in different fields. Another factor is differences in economically feasible career trajectories in different disciplines. Among twentieth and twenty-first century scientists those who made remarkable discoveries when young may be rapidly tempted into heavy administration either by promotion within institutions or by pressures to compete for grants to support bigger research teams that become managerial burdens. Their personal research creativity inevitably suffers. The funding structure of contemporary science also confuses assessments of lifetime productivity in other ways. The recent increase in publications by successful older scientists often reflects the talent and energy of outstanding young professional dependents rather than their sustained personal brilliance.
Recent studies confirm that declines in scientific productivity do occur but also suggest that they now happen much later than data available to Lehrman suggested. Studies of British psychologists in the 1970s and 1980s , of large groups of less eminent, physicists, geologists, physiologists and biochemists published in 1989 [12 ] and of recently eminent economists  all found that, as they grow older, academics do publish less, and in less prestigious journals. Nevertheless, plateaus of greatest scientific productivity now seem to last more than a decade longer than in Lehman’s day and have become less different from those in the arts. Arts practitioners now seem to peak earlier . A 1999 analysis of the number of paintings produced by 739 graphic artists, works by 719 musicians and books by 229 authors found that, like most contemporary scientists, their periods of maximum output were in their thirties and forties [14 ]. There are also hints of sex differences because the time of greatest productivity for female writers was in their fifties. This may reflect either the longer cognitive preservation of women or their late release from family pressures or, of course, both.
One problem in assessing differences between occupations is finding comparable standards for assessments. In the arts these differ sharply between various kinds of achievement, with standards of comparison and even with changes in fashion. For example, a tally of the year 2000 market value of paintings by 51 modern US artists found that for painters born before 1920 the average peak age for the valuation of their paintings was 50.6 but for those born after 1920 it was only 28.8. If we only compared data for current sale prices, we might conclude that artists who are now elderly once painted much better (or at least much more profitably) than their young contemporaries or, indeed, than they themselves did when they were young 15.
The lifetime performance of humbler, but nevertheless high-functioning, careers in industry, business and commerce is also not straightforward to interpret. Jobs require very different skills and make demands that are more or less stressful for older workers. For example, productivity at heavy manual work markedly declines between 18 and 50 and individuals older than 50 must change jobs or retire. So most of the data available for the middle aged have been collected on middle- and upper-level managers. A powerful determinant of these people’s careers has been the rate and extent of technological changes in their professions. Rapid and radical changes decrease productivity in older employees who learn more slowly. Another issue is how performance is assessed. When productivity is rated by colleagues, such as senior managers, assessments for older workers tend to be favourable. There is also evidence that older workers tend to be more poorly rated in organisations in which the average age is young than those in which it is older. Comparisons of salaries tend to favour older workers, but this is a questionable index because most studies show that job productivity is only weakly linked to salary. The general picture seems to be exactly what common sense would suggest: learning necessary skills takes time proportional to how difficult they are to acquire. More intelligent and younger people can acquire skills faster; older and less intelligent people take longer. Once skills have been learned, and particularly if they are continually practised, they can remain relatively stable into late middle age or early old age. So, if job demands do not radically change, productivity can also be maintained through the fifties and sixties and, even at this later time of life, new knowledge and competencies can be acquired, albeit more slowly and with greater effort but, hopefully, also with even greater personal satisfaction.
A broader point is that, as in all aspects of mental life, the changes that age brings about in our everyday efficiency are not only due to changes in our brains that impose new limits on our mental performance. They are also due to shifts in the resources of time and opportunity that our changing lives allow and in the particular challenges that our lives impose on us. It is not news to any of us that, in the current state of medical science we will, most likely, eventually experience illnesses that affect our mental abilities. A more interesting point is what steps we can take to delay this process so that our inevitable final periods of mental decline is as short as possible. The essential thing is to stay well and so to live long and, while we enjoy this good fortune, to continue to practise and furbish the skills that we have acquired throughout our lifetimes. This does becomes harder as we age but, if we can put up with this inconvenience we may continue doing the things that we like well enough to bring us satisfaction and happiness.
- Krampe, R. T. and Ericcson, K. A. (1996). Maintaining excellence. Deliberate practice and elite performance in young and older pianists. Journal of Experimental Psychology, General, 125, 331–359.
- Charness, N., Tuffiash, M., Krampe, R., Reingold, E., & Vasyukova, E. (2005). The role of deliberate practice in chess expertise. Applied Cognitive Psychology, 19(2), 151-165.
- Kemper, S. (1990). Adults’ diaries: Changes made to written narratives across the lifespan. Discourse Processes, 13, 207–223.
- Colonia-Willner, R. (1998). Practical intelligence at work. relationship between aging and cognitive efficiency among managers in a bank environment. Psychology and Aging, 13, 45–47.
- Colonia-Wilner, R. (1999). Investing in practical intelligence: Aging and cognitive efficiency among executives. International Journal of Behavioural Development. 23. 591–604.
- Lehman, H. C. (1935). The chronological years of greatest productivity; chemists, inventors, poets et altera. Psychological Bulletin, 32, 676–693.
- Lehman, H. C. (1942). The creative years; oil paintings, etchings, and architectural works. Psychological Review, 49, 19–42.
- Lehman, H. C. and Ingerham, D. W. (1939). Man’s creative years in music. Science Monthly, N.Y., 48, 431–443.
- Suedfeld, P. and Piedrahita, L. E. (1984). Intimations of mortality. Integrative simplification as a precursor of death. Journal of Personality and Social Psychology, 47, 848–852.
- Cassandro, V. J. (1998). Explaining premature mortality across fields of creative endeavour. Journal of Personality, 66, 805–833.
- Over, R. (1982). Does research productivity decline with age ? Higher Education, 11, 511–520.
- L. E. (1991). Size, age and productivity of scientific and technical research groups. Scientometrics, 20, 395–416.
- Levin, S. G. and Stephan, P. E. (1989). Age and research productivity of academic scientists. Research in Higher Education, 30, 531–549.
- Bayer, A. E. and Dutton, J. E. (1977).Career age and research-professional activities of academic scientists. The Journal of Higher Education, 48, 259–283.
- Galenson, D. W. and Weinberg, B. A. (2000). Age and the quality of work: The case of modern American painters, Journal of Political Economy, 108(4), 761–777.