What Happens in the Body during Adulthood? Generally, physical attributes, such as strength, reaction time, and overall body function, are at their peak during our 20s. As we move into our 30s, our bodies begin to decline slowly. Our metabolism slows, for example, so it takes a bit more work to keep some roundness from appearing around the waist.
During our 30s and 40s, we begin to show the first significant signs of aging. Skin begins to lose some of its elasticity, and gray hairs begin to sprout. Although we’re significantly past our sensory peak, we generally don’t begin to notice declines in that area of functioning until we are in our 40s (Drummond, 2011; Fozard et al., 1977). We become more farsighted, finding it hard to read or see small objects close to us, and we have difficulty seeing in the dark or recovering from sudden glares of light. We also become less sensitive to high-frequency noises.
Women in their 50s typically go through a major change called menopause (Nosek et al., 2010). Menopause involves a series of changes in hormonal function that even-tually lead to the end of the menstrual cycle and reproductive capabilities. The early phase of menopause is often associated with a variety of physical experiences, such as hot flashes, headaches, and sudden shifts in mood.
As we move into late adulthood, during our 60s and 70s, we may become a bit shorter and thinner due to changes in our skeletal structure and metabolism (Drummond, 2011;
Bord-Hoffman & Donius, 2005). Our immune systems also begin to decline in function, leaving us at higher risk for illness. Our vision and hearing continue to decline, joined by our sense of taste. Our pupils shrink, so that less light reaches the retina, making it harder for us to see in low light.
The story is not as simple as a long, slow, inevitable decline, however. Exogenous factors, such as exercise, stress, diet, and life experience, can have a dramatic influence on the course and impact of these changes (Drummond, 2011; Larson et al., 2006;
Brach et al., 2003). Although declines are common, many of the changes can be subtle and have minimal impact on how well we function in the world.
Adulthood
What Happens in the
B R A I N ?
Until recently, neuroscientists believed that our brains begin to shrink during adulthood, in terms of both volume and weight, and that much of this loss can be traced to the shrinkage and loss of active brain cells (Miller & O’Callaghan, 2005). Research over the past decade, however, has revealed that no significant loss of neurons occurs in adulthood, except in cases of brain pa-thology (Miller & O’Callaghan, 2005). On the contrary, new neurons keep forming in certain parts of the brain throughout life, including during adulthood (Leuner &Gould, 2010; Gould, 2007). These neurons may be the result of new learning or they may play a role in further learning, or both (Leuner, Glasper, & Gould, 2010; Leun-er, Gould, & Shors, 2006). Given the stability and even addition of neurons during adulthood, not surprisingly most of our broad intellectual capabilities remain intact throughout our lives (Horn & Hofer, 1992).
As we move into our 40s and 50s, however, we do begin to see some intellectual shifts (Li et al., 2004). Recovering information from long-term memory starts to take a little longer, and it takes a bit longer to learn new material. During our 60s and 70s, our memories decline, as does our confidence in our ability to remember and to solve problems (Ornstein & Light, 2010; Freedman et al., 2001). Overall, as we’ll discuss in Chapter 8, such declines tend to have a more significant impact on our ability to recall information than on our skill at solving problems or dealing with new situations.
Some declines are more serious. In dementia, severe memory problems combine with losses in at least one other cognitive function, such as abstract thinking or lan-guage (APA, 2000). The occurrence of dementia is strongly related to age. Around 1 menopause series of changes in hormonal
function occurring in women during their 50s, which lead to the end of the menstrual cycle and reproductive capabilities.
“
The first half of our lives is ruined by our parents, and the second half by our children.”
—Clarence Darrow, attorneyAdulthood How We Develop 101 to 2 percent of people 65 years of age have dementia, compared with some 50 percent
of people over 85 (Apostolova & Cummings, 2008). We’ll discuss dementia in depth in Chapter 8.
Why Do We Age? Scientists have offered many theories about why we age, but no single explanation is widely accepted (Pierpaoli, 2005). One important theory of aging, the cellular clock theory, suggests that aging is built into our cells. Tiny structures on the ends of DNA strands, called telomeres, aid in cell reproduction but grow shorter each time they are used. Eventually they become too short, and cells can no longer reproduce themselves. As a result, the body is less able to repair itself. The various changes of aging—saggy skin and decreases in vision and memory, for example—are the direct result of those events.
Two other theories of aging are more rooted in our experiences and the impact that life events can have on us. The wear-and-tear and free-radical theories suggest that years of use help wear out our bodies. The wear-and-tear theory boils down to:
the more mileage we put on our bodies through living (augmented by factors, such as stress, poor diet, and exposure to environmental teratogens), the sooner we wear out (Hawkley et al., 2005). The free-radical theory provides a chemistry-oriented explana-tion (Perluigi et al., 2010; Boldyrev & Johnson, 2007). Free radicals are oxygen mol-ecules that are negatively charged. A negative charge on a molecule can attract small particles of matter called electrons from other molecules. According to the free-radical theory of aging, free radicals become more prevalent in our system as we get older.
They increasingly destabilize cell structures and do progressively more damage to our bodies—resulting in the aging effects we have described.
Social and Emotional Development
Although the social and emotional changes that occur in adulthood are more gradual than those that characterize childhood, adults do experience multiple transitions in these spheres of functioning (Aldwin, Yancura, & Boeninger, 2010; Freund & Lamb, 2010; Holcomb, 2010). As you saw in Table 3-8, Erikson proposed that individuals confront important psychosocial conflicts as they travel from early adulthood to old age. A number of other theorists have made similar claims.
Social and Emotional Features of Early and Middle Adulthood According to Erikson, during early adulthood (20 to 30 years of age), people form intimate relation-ships and sexual unions that often call for self-sacrifice and compromise. He believed that the primary goal of this period is to attain love. The ethical convictions developed in adolescence and the sense of moral obligation formed in childhood contribute to ethical strength in young adulthood. These early acquisitions are important, he believed, because a sense of morality is required for the truly loving relationships of adulthood.
Erikson further believed that people who are unable to successfully meet the challenges of young adulthood tend to become isolated and may actually avoid the contacts that create and sustain intimacy. Thus, he concluded that young adulthood is dominated by a conflict between intimacy and isolation.
Erikson proposed that during middle adulthood (30 to 65 years of age), people are inclined to turn their attention to younger people. Their focus is to help create, or at least contribute to, the next generation. Erikson used the term generativity to describe this focus. Caring for younger people, whether through parenthood or by mentoring junior colleagues at work, is a major concern. This process enriches individuals who engage in it. Erikson believed that people who fail to develop such activities may ex-perience stagnation and boredom. Middle adulthood, then, is dominated by a conflict between generativity and stagnation.
cellular clock theory theory suggesting that we age because our cells have built-in limits on their ability to reproduce.
wear-and-tear theory theory suggesting we age because use of our body wears it out.
free-radical theory theory suggesting we age because special negatively charged oxygen molecules become more prevalent in our body as we get older, destabilizing cellular structures and causing the effects of aging.
Downward slide In this computer illustration, the green-glowing proteins at the end of the chromo-somes are telomeres, tiny structures that help cells to reproduce. The structures appear to grow shorter and shorter with repeated use, leading eventually to reduced cell reproduction and poor self-repair by the body.
Several theorists have extended Erikson’s work on early and middle adulthood. Psychologist Daniel Levinson conducted one particularly broad investigation of these life stages (Levinson, 1996, 1986, 1984, 1977). According to Levinson’s findings, the stage of early adulthood (which he defined as 22 to 40 years of age) is characterized simultane-ously by high energy and abundance and by contradiction and stress.
The aspirations of individuals in this age range tend to be youthful.
They establish a niche in society, they may raise a family, and ultimately they reach a relatively “senior” position in the adult world.
For many, this period brings great satisfaction and creativity (Simon-ton, 1990). But early adulthood can also be a period of enormous stress.
The burden of becoming a parent, undertaking an occupation, incurring financial obligations, and making other critical decisions about marriage, family, work, and lifestyle often fills people with anxiety and tension.
Levinson described middle adulthood (40 to 65 years of age) as a stage in which biological functioning, though less than optimal, is still sufficient for an “energetic, personally satisfying and socially valuable life.” During this stage, people usually become “senior members” of their particular world. They take responsibility for their own work, that of others, and the development of younger adults. This, too, can become a period of self-satisfaction and peace of mind. At the same time, growing biological problems, numerous respon-sibilities, and anticipation of upcoming old age may also produce considerable stress and tension.
Although the early and middle adulthood stages may themselves be sources of stress, Levinson found that the transition periods that people must pass through as they move from stage to stage can bring even more pressure. During such transitional peri-ods, people confront particularly difficult career, marital, and family issues and reflect on and adjust their dreams.
The early adult transition, often called “emerging adulthood,” bridges adolescence and early adulthood (Arnett, 2007). During this period, which lasts from approximately 17 to 22 years of age, people may go through a very unsettled time.
They take steps toward individuation and modify their relationships with family, friends, and social institutions. They may feel insecure in these efforts and, correspondingly, may experience anxiety and confusion. Indeed, in today’s world, more and more individuals seem to be having difficulty completing this early adult transition.
Moving Ahead? Generally, when we think of 20-somethings, we think of young people making their initial journey into independence. But increasingly, and around the world, young adults are returning home after college or are never leaving in the first place. In some countries, the trend is so strong that it has inspired special names for it. In Germany, young adults who live with their parents are called Nesthockerin, or birds that stay too long in the nest. In Italy, they’re bamboccioni, or over-grown babies. In the United Kingdom, they’re kippers, or “kids in parents’ pockets, eroding retirement savings.”
This group has received the most negative attention in Japan, where sociologist Masahiro Yamada coined the term parasite singles to describe them. Parasite singles are often accused of be-ing unwillbe-ing to take on the responsibilities of adulthood, spendbe-ing their money on nights out and personal luxuries instead. In their
© The New Yorker Collection 1989. Henry Martin from cartoonbank.com. All Rights Reserved.
Adulthood How We Develop 103 own defense, many of these young adults point out that entry-level jobs are hard to
come by, and those that are available do not pay enough. The average rent in Japan constitutes two thirds of the average young adult’s salary.
Some researchers have begun to study this widespread phenomenon and have argued that a new stage of development might be emerging, much as adolescence first developed in response to social changes that outlawed child labor and made education more widely available. But other observers consider this view to be mis-guided —a softhearted way of looking at emerging adults who simply need to grow up and get a job.
Even more stressful for some people, according to Levinson, is middle life transition, a period lasting from ages 40 to 45 that bridges early and middle adulthood. He found that during this period, individuals experience significant changes in the character of their lives. On the positive side, they may become more compassionate, reflective, and judicious during these years; less conflicted; and more accepting and loving of them-selves and others. On the negative side, some individuals may feel overwhelmed as they increasingly recognize that they are no longer young and vibrant, that time is passing, that life’s heaviest responsibilities are falling on them, that they must prepare for the future, and that some of their dreams may not be fulfilled. These persons may question their accomplishments in life and conclude that they have achieved and will continue to achieve too little. In certain cases, they may even try to deny the passage of time and to recapture their youth, a phenomenon popularly labeled the midlife crisis.
Social and Emotional Features of Old Age Our society typically defines “old age” as referring to people 65 years old and above. Psychologists further distinguish between the young-old, people between 65 and 74; the old-old, those between 75 and 84; and the oldest-old, individuals 85 and above. By this account, around 36 million people in the United States are old. They represent nearly 12 percent of the total U.S. population. By the year 2030, 20 percent of the total population is ex-pected to be “old.”
Old age brings special pressures, unique upsets, and, as we saw earlier, profound bio-logical changes. People become more prone to illness and injury as they age. They also are likely to experience the stress of loss—the loss of spouses, friends, and adult children, as well as the loss of former activities and roles (Etaugh, 2008). Some lose their sense of pur-pose after they retire. Even favored pets and possessions are sometimes lost.
Despite such difficulties and despite their awareness that death is a closer reality, elderly people do not necessarily become depressed or feel overwhelmed (Edelstein et al., 2008). Indeed, Erikson believed that, for many, old age is characterized by accu-mulated knowledge and understanding and by mature judgment. The goal of old age, he proposed, is to attain wisdom, a detached yet active concern with life in the face of death. Wisdom is achieved through integrating insights gained from the past and the present regarding one’s place in the stream of life. Erikson believed that those who do not effectively meet the challenges of this stage may experience an extreme fear of death or despair, show bitterness and disgust, and feel that time is too short. He therefore categorized old age as a conflict between integrity and despair.
Research indicates that many older persons use the changes that come with aging as opportunities for learning and growth. One case in point: the number of elderly—often physically limited—people who use the Internet to connect with people of similar ages and interests doubled between 2000 and 2004, doubled again between 2004 and 2007, and doubled yet again by 2011. Individuals such as these Web searchers seem likely to remain involved and active right up to the end of their lives, health permitting.
In addition, despite the common themes of old age, the population of elderly adults is actually quite heterogeneous. That is, older adults are more unlike than similar to one
another. Elderly people have very different life experiences, adapt to change in uniquely personal ways, and age at different rates. Thus, psychologists make a point of distinguish-ing between chronological age and functional age. Chronological age, or the number of years one has lived since birth, is regarded as little more than a “short-hand variable” be-cause it is not a true indicator of an elderly person’s functional capacities. Functional age, however, reflects the individual’s capacity to adapt his or her behavior to the changing environment. As you’ll see in Chapter 12, this aspect of aging is influenced by one’s cop-ing skills, social pursuits, emotions, motivation, and self-esteem, among other factors.