Late adulthood is perhaps the most difficult of all to define precisely – mainly because there is very wide individual variation in the physical, cognitive and social processes of aging.
In late adulthood, external physical changes include changes in the skin (wrinkling, loss of elasticity), loss of subcutaneous fat, thinning of the hair, and changes in general posture due to the loss of collagen between the spinal vertebrae (Cavanaugh, 1997; Whitbourne, 2001). There are also many internal changes, less apparent to the onlooker but important to the functioning of the aging individual. These include changes to the cardiovascular system and loss of cardiac muscle strength, decline in muscle mass and reductions in the efficiency of the respiratory, digestive and urinary systems (Whitbourne, 2001). But, although physical change is inevitable, the timing and extent are highly variable (and, to some degree, influenced by the behavioural choices and lifestyle of the individual). For example, aging of the skin is affected by exposure to sunlight, physical strength and fitness decline less in people who exercise regularly, and the well-being of the digestive system is influenced by diet and drug use (Whitbourne, 2001). Physical and sensory capacities, so important in our earliest encounters with the world, also tend to decline with age. Manual dexterity is reduced (Francis & Spirduso, 2000), and the visual system becomes less effective (Glasser & Campbell, 1998). The older person’s pupils become smaller, and the lens of the eye becomes less transparent (and so less sensitive to weak lights, and less able to adapt to darkness) and less able to accommodate. Hearing, taste, olfaction and touch all become less sensitive during later adulthood (Marsh, 1996; Whitbourne, 2001). If perceptual abilities were so vital at the outset of life, what are the psychological consequences of beginning to lose them? Imagine becoming less able to listen to music, experiencing difficulties in attending to conversations, or finding that food and drink seem less interesting. Research indicates that our physical senses remain important at this end of the lifespan, too. There is a strong connection between sensory functioning and intelligence in old age (Baltes & Lindenberger, 1997). Gradual deficits in hearing can affect older people’s ability to process speech in the context of other noise, which in turn affects how easily they interact with other people. Certainly, the decline of abilities that were once taken for granted can lead to a reduced sense of competence for the older person (Whitbourne, 2001). And the curtailment of activities that were previously enjoyed can affect people’s assessment of their quality of life. But, once again, the extent of the impact of biological decline varies from person to person, and is influenced by both the rate of change and the individual’s coping skills (which are, in turn, influenced by personality and social circumstances).
Does intellectual capacity decrease with age?
Let us return again to Schaie’s data on primary mental abilities across the lifespan. Look at the average performance of 67-year-olds compared to adults in mid-life, and you will see evidence of some decline. At this stage it is not particularly dramatic, but our eyes are drawn to the right of the figure, where we see more marked reductions in the performance of people in their 70s and 80s. It seems that by the mid 60s, the downward trend is set. But take another look. If we compare the performance of the 67-year-olds with the 25-year-olds, it turns out that they are very similar on three of the measures, and only slightly poorer on two of them. On average, people in their mid 60s are performing on these tests at roughly the same level as those in their mid 20s. Schaie’s and other research (Powell, 1994; Rabbitt et al., 2001) also shows that while there is variation between age groups on some measures of intellectual performance, there is also great variation within groups – and this variation within groups increases with age. Older people do tend to perform less well than younger adults on tasks dependent upon reaction time and processing speed (Bashore, Rindderinkof & van der Molen, 1997; Rabbitt, 1996). Some researchers have also reported that older adults perform less well on Piagetian-type tasks measuring formal operations (Denney, 1984). But these differences do not necessarily support the conclusion that intellectual capacity in the elderly is pervasively inadequate. Intelligent behaviour in everyday life typically involves several capacities, and people may be able to compensate for reductions in one ability (such as processing speed) by placing greater weight on another (such as judgments based on experience).
[Patrick Rabbitt (1934– ) was born in India but spent the majority of his working life in the UK, studying at Cambridge University and working predominantly at the Universities of Oxford and Manchester, where he established an Age & Cognitive Performance Research Unit (funded by the Medical Research Council). Rabbit developed a large longitudinal cohort, shared between Manchester and Newcastle. He has published widely and influentially, and has been especially interested in the source of inter-individual ability in adult development and ageing (focusing on issues such as speed of intellectual processing and IQ).]
Another myth debunked
Many of the studies that point to age-related differences are based on different cohorts – that is, groups of people who were born at different times, and experienced different educational systems (Baltes, 1987). Some studies compare young adults at university with older adults drawn from the broader community, which confounds education with age. Hooper, Hooper and Colbert (1985) addressed this issue by comparing students of different age groups, and found that older participants’ (aged 61–80) performance on formal reasoning tasks was comparable to those of the young people. It is tempting to interpret the declining slope from the 70s to 80s as confirming an inevitable and irreversible decline in performance. But suppose we intervened by providing training to show (or remind) older people how to perform the kinds of tasks being tested? Schaie and Willis and their colleagues have done exactly this – with impressive results! In a number of studies, they have found that ol er people’s performance can be significantly improved by training, and that these benefits endure (Schaie & Willis, 1986; Willis & Nesselroade, 1990). Even reaction time can be improved in the elderly, as Goldstein et al. (1987) demonstrated by the imaginative technique of training a group of older people on video games.
SOCIAL AND EMOTIONAL DEVELOPMENT
Theorists such as Erikson and Erikson (1997) and Levinson (1978) regarded late adulthood as another major stage of adult development. Erikson and Erikson again saw the individual as facing a conflict – this time between integrity and despair. They maintained that as people realize they are coming towards the end of their life, they reminisce about their past and review how they feel about themselves. Have I met life’s challenges successfully/ achieved goals that I value/contributed to the wellbeing of those I care about? Or have I failed to realize my potential/wasted time in pointless work or futile relationships/been a burden to others? Erikson and Erikson believed that individuals who arrive at a predominantly positive view (i.e. regarding their life as integrated and successful) experience a more contented late adulthood. Levinson saw the period from approximately 60 to 65 as the late adult transition, when the individual has to deal with intrinsic changes in capacity and performance, as well as changes i relations with others and in society’s expectations. One of the key aspects of many people’s adult life – their job – is now approaching its end, or has already concluded. All of these changes pose challenges. How do older people cope with the demands of ageing and their changing social status? Not surprisingly, the answer is that there is considerable variation.
Relations with others
As in all other parts of the lifespan, relationships are important to the older person’s adjustment (Johnson, 2001). For some people, the marital relationship may become more rewarding during old age. Some research has found that satisfaction with marriage tends to be rated higher in retired people than in middle-aged adults (Orbuch, House, Mero & Webster, 1996). This may be partly because older married people tend to be those whose marriages have been successful (i.e. they have stayed together because they were satisfied with the relationship). But it could also be because partners now provide each other with a degree of companionship and support that may not always have been so apparent or so appreciated in busier earlier years, when many other types of relationship were competing with the person’s time. On the other hand, it may be that older people of today grew up in times when marriages were expected to last, and so their more positive ratings may reflect a more traditional determination to ‘see things hrough’ (Norris, Snyder & Rice, 1997). Other social roles – such as grandparenting or great-grandparenting – are also enjoyed by many older people, and allow them to feel that they contribute to their family and to a new generation (Barer, 2001; Smith, 1995). Sibling relationships often become particularly important (Cicirelli, 1995) – by this stage, our most long-lasting relationships are usually those with our brothers and sisters. And the many positive benefits of friendships (see chapter 9) remain at least as important in the later years as they are earlier in the lifespan (Antonucci, 2001). Overall, when asked to identify the most important considerations affecting quality of life, older people consistently place personal relationships and social networks high on their lists (Antonucci, 2001). Successful ageing Although there are losses and declines with age, we have already seen that many people respond to them adaptively – one of the remarkable characteristics of human beings throughout the lifespan is ur resilience (Baltes & Mayer, 1999). For example, there is little evidence among older people of a direct link between physical decline and psychological problems such as depression (Lenze et al., 2001; Penninx, Guralnik, Simonsick et al., 1998; Shmuely-Dulitzki & Rovner, 1997). Many older people adjust well to the changes associated with ageing, and report high levels of enjoyment of life in their later years (Penninx et al., 1998). What factors promote successful aging? In many respects, this is one of the final developmental issues facing us all. In recent years, lifespan developmental psychologists have begun to provide valuable insights. As you might expect, social support and social networks emerge as primary considerations: people with better levels of social support from family and friends tend to enjoy better physical and mental health in the later years (Antonucci, 1994; Johnson, 2001; Lang & Baltes, 1997; Pearlin & Skaff, 1998). Paul and Mary Baltes and their colleagues have investigated the processes of successful aging among participants in the largescale Berlin Aging Study (Baltes & Lindenberger, 1997; Baltes & Mayer, 1999; Marsiske et al., 1995). They have proposed a model of ‘selective optimization with compensation’, according to which people face problems associated with aging by finding ways to handle cognitive tasks that minimize their dependency on their declining biological capacities. A concrete example is provided in a study of younger and older golfers conducted by Over and Thomas (1995). The younger players (average age 34 years) were stronger than the older (average age 62 years), and they had better vision, so they had the advantage when it came to driving off and striving for distance. But the older golfers had certain advantages of their own: they were less prone to be affected by negative emotions and cognitions about the game, they were better able to prepare mentally, and they were more cautious. The two age groups in fact performed to the same handicap level, but did so via different combinations of abilities. The older golfers were apparently exploiting the fact that there are some areas of intellectual performance that improve with age. Such improvements are usually connected with pragmatic reasoning rather than with mechanical/motor abilities. For example, researchers have found that older people show evidence of increasingly complex reasoning about interpersonal issues, life planning and moral dilemmas (Pratt, Golding & Kerig, 1987), and they perform better than younger adults with respect to oral narrative production (Pratt & Norris, 1994). The good news for aspirant psychologists is that a professional life involved in cognitively challenging and stimulating work appears to promote the prospects for successful aging. Indeed, Hogan (2000) points out that there are over 30 former presidents of the American Psychological Association who have lived into their 90s, often continuing their work and enjoying social and leisure activities until very late in life.