23.2 Selective Optimization with Compensation

Ageism distorts reality, but senescence is real. We need to push aside the distortions of ageism and instead look at the actual changes of aging and what can be done about them. As already described in Chapter 20, every part of the body is affected by the passage of time.

How does a person reach old age and still be vital? Several strategies were described in detail in Chapters 17, 20, and 21, specifically: decreasing allostatic load by exercising daily, eating well but not too much, avoiding cigarettes and other drugs, and coping with stress in such a way as to reduce or eliminate stressors. All these are as important in late adulthood as at any other time, perhaps even more so.

Now we highlight another strategy: selective optimization with compensation. The same principles that apply to it apply also to biological vitality. The elderly can compensate for the impairments of senescence and then can perform (optimize) whatever specific tasks they select. [Lifespan Link: Selective optimization with compensation is first described in Chapter 21.]

Every compensatory strategy involves personal choice, societal practices, and technological options. This will be clear with three examples: sexual intercourse, driving, and the senses.

Personal Compensation: Sex

Most people are sexually active throughout adulthood. Some continue to have intercourse long past age 65 (Lindau & Gavrilova, 2010) (see Figure 23.4), but generally intercourse becomes less frequent, and sometimes stops completely. Nonetheless, sexual satisfaction often increases after middle age (Heiman et al., 2011). How can that be?

Your Reaction Older adults who consider their health good (most of them) were asked if they had had sexual intercourse within the past year. If they answered yes, they were considered sexually active. What is your reaction to the data? Some young adults might be surprised that many adults, aged 60 to 80, still experience sexual intercourse. Other people might be saddened that most healthy adults over age 80 do not. However, neither reaction is appropriate. For many elders, sexual affection is expressed in many ways, and it continues lifelong.

Many older adults reject the idea that intercourse is the only, or best, measure of sexual experience. Instead, cuddling, kissing, caressing, desiring, and fantasizing become more important (Chao et al., 2011). A five-nation study (United States, Germany, Japan, Brazil, Spain) found that kissing and hugging, not intercourse, predicted happiness in long-lasting romances (Heiman et al., 2011). Is that optimization, compensation, or both?

The following in-depth study of couples might provide some answers.

To Have and to Hold In McMinnville, Oregon (left) and in Montevideo, Uruguay (right) these married couples, like many other elderly ones, enjoy their physical as well as psychological closeness.

RICK BOWMER/AP PHOTO
CATHRINE STUKHARD/LAIF/REDUX

Married couples adjust to whatever biological changes occur in their sexual arousal, but many also improve their relationship in the process (Lodge & Umberson, 2012). This is an example of selective optimization with compensation. A similar process occurs for individuals after divorce or death of a partner. Since the sex drive varies from person to person, some single elders consider sex a thing of the past, some cohabit, some begin LAT (living apart together) with a new partner, and some remarry. That is selective optimization—each older person choosing whether and how to be sexual.

Neither the old myth, that no normal older person wants sex, nor the new myth, that all older people have strong sexual desires, is accepted by elderly people themselves. Of course, with every social construction, society makes some options difficult, which leads to the next topic.

Social Compensation: Driving

A life-span perspective reminds us that “aging is a process, socially constructed to be a problem” (Cruikshank, 2009, p. 8). The process is biological, but the problem begins in the social world. That means selective optimization with compensation is needed by societies, too, not just by individuals. One example is driving.

With age, reading road signs takes longer, turning the head becomes harder, reaction time slows, and night vision worsens. The elderly compensate: Many drive slowly and reduce driving in the dark.

Relying on individuals to decide when and whether to stop driving is foolhardy, however. In the United States, driving one’s car is a source of independence, so the elderly are understandably reluctant to quit. In addition, some critics are ageist, not accurate (Satariano et al, 2012). Consequently, many old people who have driven all their lives insist they are still good drivers and resent age-based restriction. They do not want to diminish their lives.

Because they are cautious and limit themselves, elderly drivers have fewer accidents than 20-year-olds. That sometimes convinces them that they drive better than younger people.

Although older drivers try to compensate, many do not realize how significant their losses are. For instance, one common problem is a reduced ability to estimate speed of oncoming cars. Without that, it is difficult to safely merge into highway traffic. How can an older adult know that speed estimation is reduced? Must that knowledge wait until a near or real collision?

Societies need to compensate for age-related reduction in driving ability, yet often they do not. For instance, many jurisdictions renew licenses by mail, even at age 80. If an older adult causes a crash, the aging individual is blamed, not the lack of social compensation (Satariano, 2006).

If testing is required before license renewal, it often focuses on answering multiple-choice questions about stop signs and parking, and on reading letters on a well-lit chart. Anyone who fails such tests should have stopped driving long ago, but proficiency on these exams does not guarantee competent driving. For instance, judgment and reaction time are more important than book knowledge, and peripheral vision is a stronger predictor of accidents than acuity on a chart straight ahead (Johnson & Wilkinson, 2010; Wood, 2002).

Technology has now come up with a way to solve this problem. A national panel recommends simulated driving via a computer and video screen, with the prospective driver seated with a steering wheel, accelerator, and brakes (Sifrit, 2012). The results of this test could allow some 80-year-olds to renew their license, some to have their licenses revoked, and many to recognize that they are less proficient than they thought. Sadly, this test is not yet required.

And On Icy Curves … Everywhere in the world, the elderly want to keep driving. Some nations require extensive training for license renewals. This is a special safety class for elderly drivers in Germany.

AXEL HEIMKEN/PICTURE-ALLIANCE/DPA/AP IMAGES

Beyond retesting, there is much else that societies can do. Larger-print signs before an exit, mirrors that replace the need to turn the neck, illuminated side streets and driveways, nonglaring headlights and hazard flashes, and warnings of ice or fog ahead would reduce accidents. Well-designed cars, roads, signs, lights, and guard rails, as well as appropriate laws and enforcement, would allow for selective optimization: Competent elderly drivers could thus maintain independence, and dangerous drivers (of all ages) could be kept off the road.

Another society-wide initiative is sorely needed. Efficient and inexpensive public transportation, in suburban and rural areas as well as in cities, would benefit everyone. This is particularly true for the aged, as was discovered when a British law gave free bus passes to the elderly. That increased their walking and social activity, and it reduced their driving (Coronini-Cronberg et al., 2012). Social compensation and optimization again.

VISUALIZING DEVELOPMENT

Social Comparison: Elders Behind the Wheel

Older people often change their driving habits in order to compensate for their slowing reaction time. Many states have initiated restrictions, including requiring older drivers to renew their licenses in person, to make sure older drivers stay safe. Because most older drivers limit themselves (they avoid night, rainy, and distance driving), their crash rate is low overall, but not when measured by the rate per miles driven.

SOURCES & CREDITS LISTED ON P. SC-1

Technological Compensation: The Senses

Every sense becomes slower and less sharp with each passing decade. This is true for touch (particularly in fingers and toes), pain, taste (particularly for sour and bitter), smell, as well as for sight and hearing. Hundreds of manufactured devices compensate for sensory loss, from eyeglasses (first invented in the thirteenth century) to tiny video cameras worn on the forehead that connect directly to the brain, allowing people who are blind to process images (not yet commercially available).

Only 10 percent of people of either sex over age 65 see well without glasses (see Table 23.1), but selective optimization allows almost everyone to use their remaining sight quite well. Changing the environment—brighter lights, large and darker print—is a simple first step. Corrective lenses and magnifying glasses help. For those who are totally blind, dogs, canes, and audio devices have for decades allowed mobility and cognition.

Through Different Eyes These photographs depict the same scene as it would be perceived by a person with (a) normal vision, (b) cataracts, (c) glaucoma, or (d) macular degeneration. Think about how difficult it would be to find your own car if you had one of these disorders. That may help you remember to have your vision checked regularly.

© ANNA STOWE/ALAMY

By age 90 the average man is almost deaf, as are about half the women. That may be an overestimate. Since deafness is a matter of degree, it is hard to know where to draw the line. The Gallaudet Research Institute puts hearing difficulties at 29 percent over age 65; a scholar who examined U.S. Census records suggests about half that, 16 percent (Mitchell, 2006).

Everyone agrees, however, that hearing impairment increases dramatically with age and that deafness is far more common in men than in women. For all sensory deficits, an active effort to compensate—not accept—is needed. Unfortunately, ageism leads elders to avoid bifocals and hearing aids, leaving them to squint and mishear until blindness or deafness is imminent (Meisami et al., 2007).

Ageism affects whether a society provides technological help. A dramatic improvement in the ability of deaf people to enjoy concerts, plays, museums, and so on results from a “hearing loop,” a small device in a room that enables people with hearing aids to hear the words or music they want, without the distracting clatter. Installing a loop requires someone to realize that it is worth the cost. David Myers, himself now hearing impaired, explains:

Disability advocates hope more designers and engineers will think of universal design, which is the creation of settings and equipment that can be used by everyone, whether or not able-bodied and sensory-acute (Hussein et al., 2013; Holt, 2013). At the moment, just about everything, from houses to fashionable shoes, is designed for adults with no impairments. Many disabilities would disappear with better design.

Look around at the “built” environment (stores, streets, colleges, and homes); notice the print on medicine bottles; listen to the public address systems in train stations; ask why most homes have entry stairs and narrow bathrooms, why most buses and cars require a big step up to enter, why smelling remains the usual way to detect a gas leak. Then look for signs that indicate accessibility or hearing loop availability, and find out how accurate those signs are. Too often elevators are not in service, curb cuts are not smooth, ramps are hidden, and so on.

Sensory loss need not lead to morbidity or cognitive loss, but without compensation, any disability, including deafness and blindness, can lead to isolation, less movement, and reduced intellectual stimulation. Often illness increases and cognition declines as the senses fade.

Compensation for the Brain

For the three topics just mentioned in relation to physiological problems of aging—sex, driving, the senses—the critical organ of senescence is the brain. In every aspect of aging, it is the brain that selects, optimizes, and compensates.

No Quitter When hearing fades, many older people avoid social interaction. Not so for Don Shula, former head coach of the Miami Dolphins, who led his team to two Super Bowl victories. He kept his players fighting, often surging ahead from behind. Here he proudly displays his hearing aid.

MARICE COHN BAND/MCT/NEWSCOM

Thus, a person must decide that sexual touch is as rewarding as intercourse. Sexual arousal begins in the brain, not the genitals, which is why a dream, a photograph, or a voice on the phone can trigger arousal and why ageism can reduce desire.

Likewise, people must realize that their senses are fading, must decide to use technology, must find the appropriate device, and then must learn to use it. Many hearing aids stay in boxes beside the bed because the person does not know how to make them work properly.

The United States Department of Transportation has analyzed crash risk among the elderly and found that the biggest risk is in cognition, not in vision or motor skills (Sifrit, 2012). To forget which pedal is the brake is far worse than the loss of some foot strength, which might prevent an older person from pushing the brake as hard as a younger driver. The most common reason for a fatal crash with an elderly driver is that the driver turned left at an intersection into oncoming traffic—obviously a matter of judgment, not ability.

What then happens to the brain as humans age? It slows down, and connections between parts weaken, so people take longer to understand what is needed in a particular situation. Comprehension becomes more difficult because the white and gray matter of the brain are reduced. For instance, reading rate slows and conversation partners need to talk more slowly.

The volume of the brain decreases with each passing year—less than 1 percent per year through most of adulthood but accelerating after age 60 (Hedman et al., 2012). The brain volume of a typical 80-year-old is about 20 percent less than that of a typical 30-year-old.

More detailed research finds that brain shrinkage is most evident in particular regions: more in the neocortex than in more primitive parts of the brain, and especially notable in the hippocampus, the part of the brain that stores memories, and the prefrontal cortex, where decision making and planning occur. New neurons form as well, and cognitive reserve allows some brains to function well even when aging has continued for years. However, neither of these processes completely compensates for brain senescence (Stern, 2013).

Brain shrinkage and cell loss are particularly notable among the oldest-old. A comparative study finds that brain aging is similar in all primates, but humans experience losses relatively earlier in the life span than chimpanzees do—at the beginning of late adulthood instead of right before death (Chen et al., 2013). The authors speculate that as medical measures have increased the life span, the human brain survives longer than it may have been designed to do.

The brain is critical for all compensatory mechanisms just described. A person must think before any optimization occurs. Perhaps the brain is the organ that most needs the personal, social, or technological assistance described above.

The crucial question is: Can anything be done to compensate for brain losses in old age, to optimize thinking as people can optimize sex, or driving ability, or sensory acuteness? The answer is yes, sometimes. Brain plasticity is possible throughout life (e.g., Ram et al., 2011; Erickson et al., 2013). The same factors that protect the rest of the body protect the brain, especially exercise, nutrition, and avoiding drugs (including cigarettes). Beyond that, many specifics about memory and cognition affect late-life thinking. This is a major topic of the next chapter.

Not All Average A team of neuroscientists in Scotland (Farrell et al., 2009) published these images of the brains of healthy 65- to 70-year-olds. The images show normal brain loss (the white areas) from the lowest (5th percentile) to the highest (95th percentile). Some atrophy is inevitable (even younger brains atrophy), but few elders are merely average.

FROM FARRELL C, ET AL. “DEVELOPMENT AND INITIAL TESTING OF NORMAL REFERENCE: MR IMAGES FOR THE BRAIN AT AGES 65–70 AND 75–80 YEARS.” EUROPEAN RADIOLOGY 2009;19:177–183. COPYRIGHT J.M. WARDLAW.