Content uploaded by Arthur Cropley
Author content
All content in this area was uploaded by Arthur Cropley on Oct 19, 2014
Content may be subject to copyright.
75
Creative Performance in Older Adults
Arthur Cropley
University of Hamburg
Department of Psychology
Abstract
The prevailing stereotype of the relationship between intellectual productivity and age is
that there is a rapid decrease after the age of about 60. However, this view is not supported
by findings from case studies or laboratory research. When attention is focused on
creativity, much the same is true: there are indeed differences related to age, but creative
performances are seen (under appropriate circumstances) in people of all ages. Age
differences in creative performance are not due to a general deterioration, but to a
combination of cognitive changes, effects of external factors such as social norms, and
internal factors such as motivation and personality. Such findings suggest ways of
maintaining creativity, even after retirement!
1Introduction
The traditional view on the relationship between age and intellectual
productivity can be summarized in a simple manner: A rapid increase between
birth and adolescence or early adulthood is said to be followed by a plateau
lasting until the age of perhaps 50 or 60, at which point a phase of
deterioration is thought to set in and accelerate rapidly once old age makes
itself felt, ending ultimately with death. The shape of the curve is affected by
illness or injury, but it can be summarized in general terms in the form shown
in Figure 1 (Cropley 1977, p. 55).
2Weaknesses of the Model
2.1 Technical Problems
There are a number of methodological objections to this model. For instance,
the data on which it is based were mainly derived from cross sectional studies,
Arthur Cropley
76
Figure 1: Stereotype of Intellectual Growth and Decline with Age.
in which separate groups of people were tested at the same time (all the
people in a given group being of similar age), on the assumption that - to take
one example - those who are 20 today will in 30 years time be like people
who are 50 today. Methodological analyses (e.g., Baltes, Reese & Lipsitt
1980) have shown that longitudinal studies, in which the same people are
tested several times at intervals during their lives, are likely to produce
different results. For instance, as Cropley (1977) show7ed, even in a situation
in which in reality there is a constant increase throughout life, cross sectional
studies could easily yield a curve similar to that in Figure 1, purely as a result
of differences between generations and not as a result of changes within
individuals over time. By the early 1980s there was conflicting evidence from
the two sorts of studies as well as better understanding of the methodological
issues, which led to pronouncements on the "myth" of decline in intellectual
functioning during adulthood, and counter arguments that the myth was itself
a myth (see for instance Horn 1982).
2.2 Different Aspects of Intellectual Functioning
Descriptions of the relationship between age and intellectual functioning such
as the one shown in Figure 1 are merely summaries. They do not take account
of differences in the shape of the curve for different aspects of intellectual
functioning; the size of the vocabulary, for instance, increases steadily with
age (in the absence of injury, disease, or biological degeneration). They focus
on only a narrow range of aspects of intellect such as speed of problem
Creative Performance in Older Adults
77
solving, rapid and accurate access to the contents of the memory, familiarity
with the most up to date technology, and the like (aspects of ability that are
closely related to conventional school like activities). They ignore, among
other things, fantasy. Possibly more important, they take little account of the
"wisdom" arising from increased experience of life (see Baltes & Smith 1990
and Birren & Fisher 1990 for more detailed discussions). This wisdom
includes good judgment in difficult situations, understanding of the way in
which the events of life go together to form a consistent context, the ability
to place events into perspective, a grasp of the fact that life is full of
uncertainty and imponderability and that all planning must take this into
account, and similar knowledge and skills.
2.3 Differences Between People
Figure 1 also fails to take differences between individual people into account.
Some people show low levels of intellectual activity from an early age, some
continue into advanced age, or continue to be very active until death. In any
case, postmortem studies show that people maintain their level of intellectual
activity until a point where a decline leading into death occurs, regardless of
the chronological age (it should be remembered that these remarks do not
apply where the effects of injury, disease or biological degeneration are
pronounced). In other words, it is not age itself which is correlated with
reduction in intellectual activity but rather entry into the final phase of life,
which sets in relatively shortly before death. The chronological age at which
this occurs may differ very substantially from person to person. One
determinant of the age at which entry into the pre-death phase occurs (once
again, leaving aside injury, illness or premature degeneration) may be the
extent to which people remain intellectually active. According to the
principle, "Use it or lose it," those who start resting on their laurels early may
be the people who slip into the downhill part of the curve in Figure 1 at the
earliest chronological age. An appropriate German saying can be translated
as, "Those who rest rust!"
3Special Aspects of Adult Intellectual Functioning
Despite what has just been said, Knapper and Cropley (1991) concluded that
there are genuine changes in intellectual functioning with increasing age.
However, such differences do not reflect simply a general deterioration after
Arthur Cropley
78
adolescence and young adulthood, but are the result of a combination of
factors: changes in cognitive abilities (memory, thinking and learning
strategies, storage and recall of information), speed of functioning, or
preferred working conditions. Particularly important is the fact that
differences in intellectual performance at different ages may be due more to
differences in interests, motivation, self-image and the like than in ability.
With increasing age adults possess more clearly developed personal goals,
better articulated ideas about what constitutes worthwhile subject matter, and
a stronger desire to apply the results of their intellectual efforts. In addition,
they are subjected to the effects of social factors such as fear of looking
foolish. They also tend to take on different roles in their careers, older adults,
for instance, being expected to become guardians of advances already made
(managers) and supervisors or mentors of the upcoming generation, rather
than risk takers and trail blazers. Older colleagues are expected to leave the
work at the cutting edge to the younger generation. Finally, they are the
subject of social stereotypes, including the view that people over, let us say,
50 are incompetent. It is important to notice here that the differences which
do exist between children and adults and between older and younger adults
are (a) largely noncognitive in nature (involving motivation, self-image, social
pressure, etc.) and (b) qualitative (involving different kinds of content,
differences in preferred ways of working, and the like).
4Broader Understanding of Ability - Creativity
In recent years (see Cropley 1992a for a summary), the traditional concept of
intelligence has been extended by arguing that it is not only the reproductive
elements of thinking and problem solving (recognizing, remembering,
reapplying and the like - often under time pressure), that define intellectual
productivity, but that branching out, finding novel solutions, etc. (i.e.,
creativity) are also important. A combination of conventional thinking based
on factual knowledge, recall of this knowledge, logical thinking and similar
properties with the production of effective and relevant novelty yields "true"
giftedness (Cropley 1994; Facaoaru 1985).
4.1 Creativity and Age
The question that now arises is that of the relationship between creativity and
age. Concentrating on "ordinary" people who have not become famous for
Creative Performance in Older Adults
79
creativity, various authors (see Cropley in press for a summary) have
concluded that there is a curvilinear relationship between age and "creativity",
as measured by psychological tests. Scores increase until about age 6,
followed by a trough between about 6 and 16, and an increase again until
about 30. After about 30 there is thought to be a steady decline. The early,
"classic" study of Lehman (1953) reported that peak performances of people
who had actually become famous for their creative achievements occurred
most frequently between 30 and 40. This view is still widely supported (see
Simonton (1988) for a detailed analysis based on case studies of famous
people). Lehman's findings indicated that the age at which peak performances
occur varies from discipline to discipline, mathematicians tending to become
famous particularly early. Nonetheless, there is agreement in the research
literature (e.g., Cole 1979; Dennis 1966; Horner, Rushton & Vernon 1986)
that, allowing for differences in definitions and methodology, somewhere
around 40 is the most productive age. Despite this, it should be borne in mind
that many famous creative individuals continued to produce until well into
later life: Darwin, Freud and Einstein became famous in their twenties and
remained active into their seventies - those who start youngest seem to
continue longest.
4.2 Methodological Problems
A major methodological weakness of case studies of age and creativity is that
many creative people are included who died young: Naturally, such people
made their creative achievements at an early age. The picture becomes
somewhat different when people who lived into their seventies and longer are
studied separately. Lindauer (1993), for instance, studied famous artists, and
showed that the average age of peak performance was 35 for those who died
young, but 50 for those who lived longer. In general, longer lived creative
artists maintained a high peak of creativity over a period of three decades,
usually in their 30s, 40s and 50s. Peak creativity was unusual in the 20s
(although not nonexistent), and fell off in the 60s and later, although more
common after 50 than before 30. A high level of creativity even in old age is,
in fact, quite common. The psychological findings of Cornelius and Crespi
(1987) and Perlmutter (1988) that imagination persists until late in life support
the view that psychological traits connected with creativity persist into old
age.
Looking at individual people, Lindauer (1993) also reported substantial
individual differences in patterns connecting creativity with age. Even among
Arthur Cropley
80
the members of his sample of long lived artists, two reached their peak in their
20s, six, however, in their 60s. There were also noticeable sex differences.
Famous women artists produced more creative work in their 20s, men more
in their 60s or even later, although both sexes experienced their peak years
between 30 and 50. This suggests a possible social effect - in this case sex
role expectations - on the development of creativity. Root-Bernstein,
Bernstein and Garnier (1993) studied the productivity of 40 male scientists
who had all made enduring "high impact" contributions in physics, chemistry,
biochemistry and biology (including several Nobel Prize winners and a
number of men who had been nominated for the Nobel Prize, some of them
on more than one occasion, without actually winning it). The contributions of
these men were studied over a period of 20 years. Many of them went on
producing into their 50s and 60s. Those who made a single achievement early
and then ceased to be creative (although most of them continued to work
productively, if in a more or less repetitive way) tended to move into
management, whereas those who continued to be creative hated administrative
work. These authors concluded that a fall off in creativity after early
achievements is common, but by no means necessary.
4.3 Different Kinds of Creativity
One possible explanation of conflicting findings on creativity and age is that
there may be different kinds of creativity, the kind rather than the level of
creativity being age linked. Mumford and Gustafson (1988) made a distinction
which is very useful in this regard. They differentiated between "major" and
"minor" creativity. Significant breakthroughs (major creativity) may well tend
to occur between about 30 and 40, broadening and consolidating (minor
creativity) after that. Abra (1994) made a similar distinction between
"innovators" and "perfectors". He also expressed this in a somewhat negative
way, referring to "visionaries" and "plodders". These ideas suggest that there
may be age related changes in the kind of creativity, highly original ideas
tending to appear in youth (even if they are not fully thought out), perfecting
of the breakthroughs occurring later. The latter kind of creativity may require
a long period of apprenticeship: Elshout (1990), for instance, showed that
outstanding performance often requires about 20 years of preparation. Case
studies of creative achievers such as Nobel Prize winners or persons rated as
exceptionally creative by their peers (e.g., Simonton 1988; Weisberg 1986)
have been extremely fruitful in this regard. Despite exceptions such as
Mozart, achieving recognition is often a very long process: famous pianists
Creative Performance in Older Adults
81
and successful scientists, to take two examples, frequently require 15 or more
years of intensive effort before their work is recognized as creative. Howe and
Sloboda (1991) showed that children who displayed exceptional musical
talent early in their lives did not necessarily go on to become successful
musicians. If acquisition of the high technical skills necessary in many areas
for polished creative products takes 15 or 20 years, it is not hard to see why
creativity in the form of consolidating, broadening and perfecting would be
rare before the age of 40 or so. On the other hand, the inspired shot in the dark
or the sudden breakthrough, even if in an unpolished form, would be perfectly
possible at younger ages, or might even be encouraged by impulsiveness,
rebelliousness or absence of fear of losing face, characteristics commonly
associated with youth.
5Factors Affecting Creativity in Older Adults
From a psychological point of view, differences between older adults and
children in creative performance may be regarded as stemming from internal
factors such as intelligence, motivation or personality, or from external factors
(characteristics of the external world). Naturally, these two areas may interact
with each other - for instance, characteristics of the environment may affect
the acquisition of skills or the development of personality. Both internal and
external factors are subject to developmental processes; new skills are
acquired with increasing age and motivational changes, while an individual's
position in the community or the expectations other people have of the
individual change with that person's age.
5.1 Cognitive Factors
Differences of the kind just mentioned between older and younger people may
result from patterns of cognitive development (Piaget 1973). In children, there
is a progression from the preoperational stage (thinking focuses on concrete
attributes of objects and events) to the formal operational (thinking takes
account of abstract "meaning"). Urban (1991) identified six developmental
stages of creativity (admittedly in children) which were based on cognitive
development in the sense just outlined. One of the most important cognitive
factors in adult creativity identified by Walberg and Stariha (1992) was use
of existing knowledge as the basis of novel ideas. This was followed by
Arthur Cropley
82
alertness to novelty and knowledge gaps (see Cropley's (1992b) discussion of
"openness to the spark of inspiration"). Age differences in level or kind of
creativity may reflect the known tendency of younger people to
"accommodate" cognitively to new experiences (i.e., to alter existing ideas on
the basis of new information) in contrast with the tendency of older people to
"assimilate" (i.e., to integrate new information into existing knowledge).
5.2 Motivation
Another important area where age probably plays a role is that of motivation.
Various authors (see Walberg & Stariha 1992 for a summary) have concluded
that the major motivational factors observed in creative adults are
perseverance, discipline and commitment to a field or content area.
Committed work in a field over a lengthy period of time can hardly be
expected from children, if for no other reason than that the brevity of their
lives prior to the time when they are studied in research projects makes long
term commitment impossible. Also important are the influence of the norms
of formal education (emphasis on logic and accuracy). In an international
context, Shoumakova and Stetsenko (1993) in Russia and Heller (1994) in
Germany reported that thy had detected a reduction in creativity with
increasing schooling. Also important are social norms (adults are expected to
"be their age" and come to grips with the realities of life at the expense of
fantasy or play), demands of family, job or career and finally, physiological
factors such as changes in memory and thinking speed. Ruth and Birren
(1985) emphasized this latter group of factors in an unusual study of creativity
at various age levels, including old age.
5.3 Social Factors
Studies of creativity in eminent creative adults (see Walberg & Stariha 1992
for a brief but informative summary) have shown that expectations - in this
case the expectations of parents when the creative adults were still children -
seem to play a role in the emergence of creativity. In older adults there is a
clear societal expectation that they will become passive and inactive. The
effects of this expectation on creative productivity in later adulthood were
demonstrated by Lindauer's (1993) finding that artists who kept on working,
instead of retiring, continued to do creative work until into their old age.
Making a similar point with a different group of creative workers, Dudek and
Hall (1991) showed that architects who resisted retiring were creatively
productive for many years more than those who retired early. Such findings
Creative Performance in Older Adults
83
suggest that the social convention of ceasing to work at about age 60, not
disappearance of the psychological potential for creativity, may be a major
causal factor in reduced creativity at older ages.
Another social factor connecting creativity with age was discussed by Abra
(1994). He showed that achieving spectacular breakthroughs may require
cooperation with others. This might take the form of brainstorming or similar
kinds of interaction. Older people, especially those who have already achieved
creative products, may find it more difficult to work with partners,
accustomed as they are to being the star of the show. In their study of creative
scientists, Root-Bernstein, Bernstein and Garnier (1993) found that a major
difference between the men who continued to be creative over a long period
of time and those who made creative achievements early in life and then
ceased to be creatively productive (although they were often active for many
more years, producing however only "plodding" work after the breakthrough)
was that the lifespan creators frequently worked on several problems
simultaneously, or even switched areas of focus several times. They were
willing to go back to being novices again. Root-Bernstein (1989) spoke of the
"novice effect" in this regard. Working in the same area over a long period of
time leads to high levels of familiarity with the field, but blunts the acuteness
of the vision or inhibits openness to the spark of inspiration (Cropley 1992b).
The novice, by contrast, is not inhibited by long years of work on narrow
details. Returning to novice status requires doing without the self-confidence
that arises from knowledge of one's own souverainity in an area and without
the respect from others which is part of being an acknowledged expert.
6The Value of Creativity for Older Adults
The research summarized to date indicates that creative productivity is
perfectly possible in older adults. However, "is possible" is not the same as
"is necessary". Why should older people continue to seek to be creatively
productive, rather than, for instance, accepting the social stereotype of
passivity or even retiring as early as possible?
6.1 Everyday Creativity
Arguments why creativity should be fostered usually emphasize that a society
needs creative performances from scientists, engineers, managers, artists and
Arthur Cropley
84
scholars if it is to flourish, creative people being seen, essentially, as human
capital (see for instance Walberg & Stariha 1992). However, a number of
authors have introduced the idea of creativity as a characteristic of "people
who will never produce anything original and useful" (Nicholls 1972), or
"everyday creativity" (Merzel 1988). Interest in this chapter is in creativity as
something of which all people are capable. However, this requires a focus on
creativity not as the bringing forth of products hailed as creative (objects,
works of art, ideas, techniques and methods), but as a psychological process
involving cognition (thinking, reasoning, problem solving), motivation
(willingness to take risks, persistence, desire for novelty) and personality
(resistance to conformity pressure, self-confidence, flexibility).
6.2 Creativity and Mental Health
Research indicates that creativity is connected with psychological properties
such as flexibility, openness, autonomy, humour, willingness to try things,
realistic self-assessment, and similar characteristics. These properties have
been established in studies of highly creative people (see Cropley 1992a for
a summary). They are usually thought of as prerequisites for the emergence
of creativity. However, research on normal personality development also
emphasizes similar properties as core elements of the healthy personality.
Adopting a psychoanalytic position, Anthony (1987) argued that creativity is
related to ego autonomy, ego autonomy to mental health, with the
consequence that creativity and mental health are related. In humanistic
psychology (e.g., Maslow 1954; Rogers 1961) healthy personality
development requires openness, flexibility and tolerance, characteristics of the
creative personality. Krystal (1988) showed that uncreative people had
difficulty in "self-caring" and lacked "self-coherence". Fostering creativity in
such people would promote self-realization. Emphasizing cognitive processes,
Hudson (1963) made the point that noncreative people tend to be narrow and
rigid in dealing with information from the external environment, whereas
creative individuals show openness and flexibility in dealing with such
information. Narrowness and rigidity help achieve a sense of certainty and
security, but at the expense of healthy personality development. According to
Burkhardt (1985), modern life is marked by a "mass psychosis" which has at
its core an obsession with sameness and uniformity. Creativity is, of course,
concerned with novelty and difference.
Thus, it can be argued that creativity is connected with psychological
characteristics (such as openness, autonomy and flexibility) which are
Creative Performance in Older Adults
85
important in maintaining mental health. Although it is not clear whether there
is a cause and effect relationship between creativity and mental health, the
two seem to be connected, at least at the level of everyday creativity. The
position may be different with people who become famous for creative
achievements. Lombroso (1891), for instance, argued that genius and madness
are closely allied, and this view has been repeated in later research (see
Cropley 1990 for a review). Jamison (1989) showed that manic states were
prominent in many famous artists and writers, including Byron, Shelley,
Coleridge and Poe. Nonetheless, Richards and Kinney (1990) concluded that
psychosis does not seem to be conducive to creativity, while May (1976)
concluded that it is inimical. There are, then, grounds for believing that
creativity, even in the humble sense of everyday creativity, encourages
healthy personality development and mental age. This conclusion provides a
strong argument for the importance of maintaining creativity even at advanced
age.
7Conclusions: Remaining Creative After Retirement
The research summarized here suggests that creative productivity is perfectly
possible in older adults. However, certain psychological characteristics seem
to be necessary - or at the very least favourable - for creativity in later life.
These include maintenance of sensitivity to problems and openness to the
novel, continuing ability to accommodate to new knowledge (see earlier
discussions of assimilation versus accommodation), willingness to work hard,
commitment to an area or an idea, willingness to revert to nonexpert status or
to thinking untrammelled by the strict logic or knowledge of what is and is not
possible acquired over a lifetime, and ability to work with others, conceivably
in a relationship in which being older does not imply lead to fear of losing
face or a unwillingness to risk failure.
Bibliography
Abra, J. (1994). Collaboration in Creative Work: An Initiative for Investigation. Creativity
Research Journal, 7, 1-20.
Anthony, E.J. (1987). Risk, Vulnarabilty and Resilience: An Overview. In E.J. Anthony &
B.J. Cohen (Eds.), The Invulnerable Child (pp. 3-48). New York: Guilford Press.
Baltes, P.B. & Smith, J. (1990). Towards a Psychology of Wisdom and its Ontogenesis. In
R.J. Sternberg (Ed.), Wisdom - Its Nature, Origins and Development (pp. 87-120).
Cambridge: Cambridge University Press.
Arthur Cropley
86
Baltes, P.B., Reese, H.W. & Lipsitt, L.P. (1980). Lifespan Developmental Psychology.
Annual Review of Psychology, 31, 65-110.
Birren, J.E. & Fisher, L.M. (1990). The Elements of Wisdom: Overview and Integration.
In R. J. Sternberg (Ed.), Wisdom - Its Nature, Origins and Development (pp. 317-322).
Cambridge: Cambridge University Press.
Burkhardt, H. (1985). Gleichheitswahn Parteienwahn. Tübingen: Hohenrain.
Cole, S. (1979). Age and Scientific Performance. American Journal of Sociology, 84,
958-977.
Cornelius, S.W. & Crespi, A. (1987). Everyday Problem-solving in Adulthood and Old
Age. Psychology and Aging, 2, 144-153.
Cropley, A.J. (1977). Lifelong Education: A Psychological Analysis. Oxford: Pergamon.
Cropley, A.J. (1992a). More Ways than One. Fostering Creativity in the Classroom.
Norwood: Ablex.
Cropley, A.J. (1992b). Glück und Kreativität: Förderung von Aufgeschlossenheit für den
zündenden Gedanken. In K. Urban (Ed.), Begabungen entwickeln, erkennen und fördern
(pp. 216-221). Hannover: University of Hannover, Faculty of Education.
Cropley, A.J. (1994). Creative Intelligence: A Concept of "True" Giftedness. European
Journal for High Ability, 5, 6-23.
Cropley, A.J. (In press). Kreativität. In K. Pawlik & M. Amelang (Eds.), Handbuch der
differenziellen Psychologie, 2. Göttingen: Hogrefe.
Dennis, W. (1966). Creative Productivity Between the Ages of 20 and 80. Journal of
Gerontology, 21, 1-8.
Dudeck, S.Z. & Hall, W.B. (1991). Personality Consistency: Eminent Architects 25 Years
Later. Creativity Research Journal, 4, 213-231.
Elshout, J. (1990). Expertise and Giftedness. European Journal for High Ability, 1,
197-203.
Facaoaru, C. (1985). Kreativität in Wissenschaft und Technik. Bern: Huber.
Heller, K.A. (1994). Können wir zur Erklärung außergewöhnlicher Schul-, Studien- und
Berufsleistungen auf das hypothetische Konstrukt "Kreativität" verzichten? Empirische
Pädagogik, 8, 361-398.
Horn, J.L. (1982). The Aging of Human Abilities. In B.J. Wolman (Ed.), Handbook of
Developmental Psychology. Englewood Cliffs: Prentice Hall.
Horner, K.L., Rushton, J.P. & Vernon, P.A. (1986). Relation Between Aging and Research
Productivity of Academic Psychologists. Psychology and Aging, 1, 319-324.
Howe, M.J.A. & Sloboda, J.A. (1991). Early Signs of Talents and Special Interests in the
Lives of Young Musicians. European Journal for High Ability, 2, 102-111.
Hudson, L. (1963). Personality and Scientific Aptitude. Nature, 196, 913-914.
Jamison, K.R. (1989). Manic-depressive Illness and Accomplishment: Creativity
Leadership and Social Class. In F.K. Goodwin & K.R. Jamison (Eds.), Manic-depressive
Illness. Oxford: Oxford University Press.
Knapper, C.K. & Cropley, A.J. (1991). Lifelong Learning and Higher Education. London:
Kogan Page.
Krystal, H. (1988). On Some Roots of Creativity. Psychiatric Clinics of North America, 11,
475-491.
Lombroso, C. (1891). The Man of Genius. London: Scott.
Lehman, H.C. (1953). Age and Achievement. Princeton: Princeton University Press.
Creative Performance in Older Adults
87
Lindauer, M.S. (1993). The Span of Creativity Among Long-lived Historical Artists.
Creativity Research Journal, 6, 221-240.
Maslow, A.H. (1954). Motivation and Personality. New York: Harper.
May, R. (1976). The Courage to Create. New York: Bantam.
Merzel, A. (1988). Creativity in Manic-depressives, Cyclothymes, their Normal Relatives,
and Control Subjects. Journal of Abnormal Psychology, 9, 281-288.
Mumford, M.D. & Gustafson, S.B. (1988). Creativity Syndrome: Integration, Application
and Innovation. Psychological Bulletin, 103, 27-43.
Nicholls, J.G. (1972). Creativity in the Person who Will Never Produce Anything Original
and Useful: The Concept of Creativity as a Normally Distributed Trait. American
Psychologist, 27, 717-727.
Perlmutter, M. (1988). Cognitive Potential Throughout Life. In J. Birren & V. Bengston
(Eds.), Emergent Theories of Aging (pp. 230-241). Hillsdale: Erlbaum.
Piaget, J. (1973). Memory and Intelligence. London: Routledge & Kegan.
Richards, R. & Kinney, D. (1990). Mood Swings and Creativity. Creativity Research
Journal, 3, 202-217.
Rogers, C.R. (1961). On Becoming a Person. Boston: Houghton Mifflin.
Root-Bernstein, R.S. (1989). Discovery. Cambridge: Cambridge University Press.
Root-Bernstein, R.S., Bernstein, M. & Garnier, H. (1993). Identification of Scientists
Making Long-term High-impact Contributions, with Notes on their Methods of Working.
Creativity Research Journal, 6, 329-343.
Ruth, J.-E. & Birren, J.E. (1985). Creativity in Adulthood and Old Age: Relations to
Intelligence, Sex and Mode of Testing. International Journal of Behavioural
Development, 8, 99-109.
Shoumakova, N. & Stetsenko, A. (1993). Exceptional Children: Promoting Creativity in
a School Training Context. In International Society for the Study of Behavioural
Development (ISSBD) (Ed.), Symposium Abstracts of the Twelfth Biennial Meeting of
ISSBD (p. 23). Recife: ISSBD.
Simonton, D.K. (1988). Age and Outstanding Achievement: What do we Know After a
Century of Research? Psychological Bulletin, 104, 251-267.
Urban, K.K. (1991). On the Development of Creativity in Children. Creativity Research
Journal, 4, 177-191.
Walberg, H.J. & Stariha, W.E. (1992). Productive Human Capital: Learning, Creativity and
Eminence. Creativity Research Journal, 5, 323-340.
Weisberg, R.W. (1986). Creativity: Genius and Other Myths. New York: Freeman.