As with all thinking, it is widely subjective to change, and in early adulthood, this is no different. It has been suggested that many life events can trigger new patterns of thinking resulting in cognitive growth. McAdams (1993) found that young adults who had their first child began thinking about themselves and their responsibilities differently, concluding that parenthood is indeed imperative for cognitive growth.
When a person reaches middle adulthood, changes in cognitive growth become more evident. Intelligence is something people fear will decline with age. Some intellectual functions increase with age, some peak early and are maintained and others show decline into early adulthood. Obviously conclusions regarding changes in intellectual ability will differ depending on the functions that are being evaluated. Labouvie-Vief (1976) found a plateau in intelligence test scores during the early adult years when fluid and crystallised intelligence weren’t separated. Horn and Catell (1967) found that fluid intelligence declined after age 14 which indicated poorer abstract thinking, inductive reasoning, relational thinking and short term memory. They also discovered at least 20 studies that showed an increase in crystallised intelligence throughout adulthood. They believe this was caused by learning and life experiences accumulated over the years. Schaie (1989) felt that the decline in fluid intelligence was due to a generational gap, as the results were based on cross sectional studies. He felt that older subjects were poorly educated and had fewer opportunities and less intellectual stimulation during their lifetime compared to the younger subjects. It is found that adults score better if the test items are relevant to their daily lives (Schaie, 1989). Other factors such as motivation and personality traits can also negatively affect test scores. Physical factors such as overall health, eyesight and reaction time are especially important when measuring intelligence (Perlmutter 1988). Numerous studies in middle aged and older adults find that training in a specific area such as problem solving can result in greatly improved proficiency levels (Schaie, 1989).
As mentioned earlier, adults around this age tend to use formal operational thinking. It is estimated that approximately half of the adult population may never obtain the full stage of formal thinking (Kuhn, 1979). This may be because individuals approach problems in different ways (Rogers, 1980).
Creativity is also another area of adult cognition that is subject to change. Much has been written about developing creativity in children, but little about developing adulthood creativity. This may lead people to believe that creativity declines in adulthood. Lehman (1962) found most people produced their greatest proportion of superior work in their 30’s and later weakened in high quality production. He discovered that the fields of work that are characterised by an early peak and steep decline include lyric poetry, pure mathematics and theoretical psychics. These findings have also been replicated in other cultures and historical periods.
As a person moves into late adulthood, it is a stereotypical belief that everything starts to deteriorate, especially memory. All studies of memory recognise three basic processes; acquisition, storage and retrieval. Memory efficiency depends on all three of these processes. It is true that memory declines with age when measuring it in terms of speed (Rice, 1995); however, there are many exceptions to the rule. If ample time is given for registering, assimilating, coding and rehearsing, many older persons do as well, if not better that the younger subjects. When studying both explicit and implicit memory, it is apparent that implicit memory is much less vulnerable to age related difference than explicit memory is (Perlmutter, 1988). This is partly due to atomicity; well learned automatic behaviour. It may also be due to the fact that implicit memory is more personal and has more relevance to the individual. Being younger, healthier and more educated favours better memory performance (Rogers, 1980).
Apart from declining memory and other negative changes in cognition that occur with old age, there are also some positive ones. Many of the major theorists on human behaviour believe that older adults can develop new interests, new patterns of thought and a deeper wisdom (Berger, 2001). In old age, many people become more reflective and philosophical and may review their life. This is where a person remembers various highs and lows, compares the past to the present and renews links with people. There is also an aesthetic sense that accompanies life review. Many older people begin to appreciate nature and aesthetic experiences in a deeper way (Berger, 2001).
One of the most positive attributes associated with old age is wisdom. Wisdom is clearly an elusive concept and is bound to be partly subjective. Paul Baltes (1992) defines wisdom as ‘expert knowledge in the fundamental pragmatics of life’. Wisdom involves elements of both dialectical thinking that emerges in early adulthood, and the refinement of thinking that comes with years of personal experience. It does seem that the idea of growing wise with age may be one of the benefits of growing older.
Because adult cognition is so extensive, there are two very different viewpoints; the decramentalist view and the continued-potential view. The decramentalist view follows a pattern of universal, inevitable decline in cognitive growth over the adult years, but there are no real meaningful conclusions that can be drawn from the data. Although there is a weakening in certain cognitive abilities over time, results are too unreliable (Lemme, 1995).
On the other hand, the continued-potential view is more favourable. Accumulating evidence supports the view that although some cognitive abilities may decline, age can also offer new and improved cognition. This is a more balanced view in which cognitive development is characterised by growth and decline.
But cognitive change is a difficult thing to measure accurately because of the different causes and factors that can interfere with results. Simple things such as gender, socioeconomic status and even diet have been shown to affect results. Some studies have shown that men perform at higher levels than women on tests of intellectual ability (Bee, 1996). Level of education, occupational status and income have all been negatively correlated with the rate of cognitive decline (Perlmutter, 1988). Culture has also been shown to cause change in cognition, as Soviet psychologist L. Vygotsky (as cited in Lemme, 1995) believes that cognition is ‘socially formed and culturally transmitted’. There is also the issue of stereotyping. Under the influence of expectations, people aged 50-70 tend to overestimate the memory skills they had in early adulthood, causing obscure results (Sinnott, 1998).
Brain function is also a major cause of cognitive change. There are notable differences between neurons as the aging process occurs. The brain also becomes markedly smaller in late adulthood than it was in the earlier stages (Berger, 2001).
It does seem that out of all the causes of cognitive change, problems with research seem to be the biggest. This is because it can lead people to believe things that aren’t necessarily true. Some research procedures exaggerate cognitive decline because their designs inadvertently ‘stack the deck’ against older people (Berger, 2001). Because of these reasons and countless others, it is extremely difficult to pinpoint specific causes of cognitive change across the adult life span.
Research in adult cognition is vast, but is still in need of clear and precise findings that can make sense of it all. It is almost impossible for anyone to know the direct causes of change in intelligence, memory, creativity, information processing or any other cognitive ability because of the unsure testing methods and the inconsistent research. There are too many other conflicting factors that add to this confusion. It is obvious that in recent times, there has been a move away from the decramentalist view and a move towards the continued-potential cycle of adult cognition. This is a great change, especially in our society, because it may one day spare the negative stigma associated with aging. So in the end it seems that a butterfly is a much more positive and hopeful metaphor to describe the cognitive changes throughout adulthood. We should now be optimistic that the future will bring a better understanding of this most precious human capacity.
