In Our Prime (25 page)

Sternberg, a former president of the American
Psychological Association and an editor of
A Handbook of Wisdom,
stressed that a quality like wisdom can be understood only in a particular context. Wisdom rests on values that are aimed at achieving the common good, a point of view that sounds remarkably like Erikson's definition of generativity, the caring stage of life reached in middle age. In Sternberg's eyes, wisdom is about balancing various interests and circumstances.

Such a definition has as much to do with a particular value system as it does with any ostensibly scientific explanation of intelligence.
The influential Harvard psychologist Howard Gardner
, who came up with a “theory of multiple intelligence” in 1989, insists that language and logic intelligence, which are generally what can most easily be tested, are not superior to the five other types of intelligence he identified: musical, spatial, personal, environmental, and bodily intelligence. Other researchers have turned to more metaphysical definitions and talked about “higher awareness,” merging the spiritual realm with the intellectual. “Wisdom is a process versus a state of being,” as one psychologist put it. This perspective on human intelligence differs dramatically from the one George Miller Beard gave in the nineteenth century, when he examined the accomplishments of history's geniuses and determined that their best work was done before age 40 or 45.

New ideas about intelligence have painted a much more positive view of middle age. One by-product of the widening definition of wisdom has been to jettison the belief that youth and cognitive ability always walk hand in hand.

“
While the theme of youth is flexibility
, the hallmark of adulthood is commitment and responsibility,” Gisela Labouvie-Vief, a psychologist at Wayne State University, argues. “Careers must be started, intimacy bonds formed, children raised. In short, in a world of a multitude of
logical possibilities, one course of action must be adopted. This conscious commitment to one pathway and the deliberate disregard of other logical choices may mark the onset of adult maturity.” Looked at from an evolutionary perspective, perhaps there is a reason that particular mental skills improve in midlife while others fall off; the mature brain is confronted with a different set of tasks and problems that require another set of abilities.

The notion of the developing brain contradicts the assumption, held for most of the twentieth century, that the brain stopped progressing in adulthood. Just as psychologists assumed personality was fixed before school age, so did neurologists mistakenly assume nerve cells in the brain stopped growing in childhood, another iteration of the theory of inborn limits. With fMRIs, scientists can now see what differentiates youthful and mature judgment in the brain's circuitry, and, as it turns out, the passage of time endows the brain with certain advantages. Recently, neuroscientists have found that myelin losses in middle age can be offset and possibly superceded by increases elsewhere. Meanwhile, experience imprints itself into the mass of cells, carving new neural pathways and cataloging responses that can be called up as templates when needed, whether you are a London cabbie or a stranded tourist. Recognizing patterns that you have encountered before is one of the brain's most powerful tools.

Gene D. Cohen, the former director of the Center on Aging, Health & Humanities at George Washington University, illustrated the kind of original, creative thinking that can come only from experience.
His in-laws, both in their 70s
, got stuck in a snowstorm on their way to visit the Cohens in Washington, D.C. They couldn't find a cab and were unable to reach either their daughter or her husband by phone. Then they spotted a pizzeria and his father-in-law had an idea. The couple went inside, ordered a pizza to be delivered to their daughter's home, and then made an unusual request: Could they ride with the delivery man to the house? This type of thinking—the ability to extract a new strategy from a vast repertoire of previous experiences—is what is known as “pragmatic creativity in everyday problem solving,” or, to use a more technical term, “crystallized
intelligence.” Heavily influenced by education, crystallized intelligence is distinguished from the more biologically based “fluid intelligence,” which involves quick reasoning and abstract thinking. This may be why middle-aged people are often better in the face of adversity than 20- and 30-somethings; they have been through it before. What might have floored someone in her early years is taken in stride by someone in her middle decades.

About a thousand miles east
of Madison, where Richard Davidson is peering inside the skulls of test subjects, Margie Lachman and Patricia Tun, two psychologists at Brandeis University in Waltham, Massachusetts, are conducting the second of MIDUS II's brain studies. Lachman and Tun wanted to explore what activities or circumstances—from attending college to running laps to playing Sudoku—might protect mental abilities, or for that matter, diminish them. They reviewed the array of mental skills and selected the ones most vulnerable to aging. The duo devised a fifteen-to-twenty-minute phone interview consisting of several quick memory, verbal ability, and reasoning tests to measure these thinking processes, which they administered to 4,500 of the survey participants.

A trained interviewer initiated each
assessment by saying: “We suggest that you close your eyes while you are doing these to help you concentrate. . . . Some of the questions will be easy for you, and some will be harder. We do not expect anyone to get all of these correct—just do the best you can.” She then recited a list of fifteen words:

 

Drum

Curtain

Bell

Coffee

School

Parent

Moon

Garden

Hat

Farmer

Nose

Turkey

Color

House

River

 

Ninety seconds later, the interviewer asked: How many of those words can you remember? Numbers were next, only this time the subject was asked to repeat the series of digits backward. So for “2, 4” the correct answer is “4, 2.” Now repeat these eight numbers in reverse order: “9, 4, 3, 7, 6, 2, 5, 8.” Another test was like a version of the television game show
$100,000 Pyramid
. The interviewer named a category, and the respondent had one minute to list as many items as possible. Fruit? Pear, apple, grapes, and so on.

At the end of the handful of tests, the researcher once again asked how many of the fifteen words from the original list the subject remembered. Sometimes respondents were embarrassed when they could not recall very many, or worried they had failed. So interviewers were advised to reassure them: “Remember, we do not expect anyone to get all of these questions correct,” or “Don't worry. We have deliberately made these questions challenging. If people could get them all right, we would not learn anything. We're trying to find which questions are harder than others.”

As they expected, Lachman and Tun found that younger people performed better than the middle-aged on tests involving speed and memory. The middle-aged brain, it seems, is more easily distracted and has more trouble retrieving information. Where people in midlife excelled was in decision-making skills and verbal ability, tasks in which their experience and accumulated knowledge, their crystallized intelligence, could be put to use. Financial planning and vocabulary are two areas that show marked improvement in midlife, Lachman told me.

The preliminary results
from their tests are not quite as upbeat about the abilities of the middle-aged brain as other recent research. The Seattle Longitudinal Study that K. Warner Schaie launched in 1956 has been tracking the mental abilities of six thousand people every seven years. The 2005 check-in showed that after repeated tests of six important
cognitive abilities, middle-aged subjects from age 40 to the early 60s scored better on four of the six (vocabulary, verbal, spatial perception, and the most complex skill, inductive reasoning) than people in their 20s (who scored better on number ability and perceptual speed). Sherry Willis, a psychologist at Penn State University who co-directs the project (and is also Schaie's wife), reported: “For both men and women, peak performance . . . is reached in middle age.” In those categories, people in midlife functioned at a higher level than they did at 25.

“Contrary to stereotypical views of intelligence and the naïve theories of many educated laypersons, young adulthood is not the developmental period of peak cognitive functioning for many of the higher order cognitive abilities,” she said.

The discrepancy with MIDUS's
results is puzzling. Perhaps one test is more sensitive than another at detecting a fall-off in ability; in timed tests, for example, younger subjects tend to perform better. The Seattle study did not add some of the most age-sensitive tests until 1997. Where the subjects came from and what generation they belong to may also make a difference. The Seattle participants all lived in the vicinity, whereas the MIDUS sample comes from across the nation (in which case Seattle may shoot up on Rand McNally's list of most desirable places to live).

“We just don't know why yet,” Lachman said from her office at Brandeis. Some researchers think the brain may be capable of devising ways to compensate for a drop in memory retrieval and other tasks as it ages. Recalling a word or recognizing a face is an activity that occurs on the left side of the brain in young adults. Some lucky, high-performing middle-aged and older adults may be able to recruit both hemispheres or another region to accomplish the same task. Perhaps the brain is reorganizing its neural networks to compensate for weaknesses, just as a right-handed person might, after an injury, learn to carry out more tasks with his left hand.

Lachman and Tun, like Davidson, hope to discover what people in middle age can do to protect and strengthen both their mental and physical health. That task has taken on greater urgency in recent years as more and more middle-aged adults watch loved ones struggle with Alzheimer's and dementia and worry that their own mental powers might
fail as they move into old age. The Brandeis professors are examining why some people in their 60s are as quick on fluid intelligence tests as those in their 40s, and vice versa. Is there something the fast-responding 60-year-olds are doing to keep their brains fit, or are the slow-responding 40-year-olds engaging in behavior that impedes their skills? How important is innate intelligence or education?
So far, the professors have found
that up to the age of 75, “people with college degrees performed on complex tasks like less educated individuals who were ten years younger.” In other words, for those in midlife and beyond, a college diploma subtracted a decade from one's brain age. One theory is that native intelligence or education, or both, act like weatherproofing and add a protective coating against mental deterioration.

Most encouraging was evidence that
people without a college diploma could build up this mental weatherproofing in middle age by regularly stimulating their minds—attending lectures, reading, writing, and playing word games. “They looked very different from other low-education counterparts,” Lachman said; their brains appeared younger. The mental exercises seemed to hone the responsiveness of the brain's neural circuits.
Using a computer
was also associated with better brain functioning, particularly among people with less education. Those who spent more time in the digital world had better memory and reasoning skills, and they could process information and switch tasks more quickly, an element of making CEO-type decisions. It could be that searching the Internet or even playing video games requires people to multitask, shift attention, and coordinate motor, sensory, and cognitive skills in a way that bolsters brain functioning. People who were disadvantaged in terms of income and education seemed able to make up some of the mental workout they had previously lost out on, and therefore, showed the most progress.

Lachman cautioned that there is still a lot more research to be done, but she was buoyed by the results: “Many of the previous studies have focused on people who already have a good memory. One of the new pieces our study uncovered is that there is hope for those who need it most, those with less formal education, who are at greater risk for memory problems.”

She and Tun also discovered another unexpected brain booster: confidence that you can influence what happens in your life. People who
believe
they are able to protect their mental functioning end up doing exactly that. The belief operates in a self-reinforcing loop: you do more to keep your brain healthy (like diet, exercise, and playing word games) because you think it will make a difference; and it makes a difference because you do more.

Lachman found the same phenomenon
more widely when the latest batch of survey data from MIDUS II came in and she compared what subjects did over the course of ten years to stay healthy and happy. Feeling in control of your life (one of the six components of
eudaimonia,
that full-bodied flourishing) works on the emotional, physiological, and behavioral levels simultaneously by enhancing your self-esteem, lowering your levels of stress hormones, and spurring you to adopt a healthy lifestyle. After analyzing thousands of survey responses, Lachman discovered that, along with a satisfying network of relationships and physical exercise, a sense of control in midlife can dramatically reduce disability and preserve one's health and independence for years to come. Like Tinkerbell, whose existence depends on a belief in fairies, improving your health in middle age and beyond depends on the belief that you can improve your health in middle age and beyond.

Thanks to MIDUS and other research efforts focused on midlife, nearly every day brings new revelations, trivial and significant, about middle age. Unlike experts in the 1920s, who had a narrow physiological view, researchers have discovered just how multidimensional middle age is. In unexpected ways, MIDUS I and II have overturned the stereotypical view of midlife as a time of shrunken possibilities. Faith in self-improvement as a path to happiness has been a recurrent theme in American life. It powered consumer-driven prosperity in the twentieth century; it motivated people to surgically alter their noses; and it inspired Erik Erikson and other scientists to argue that human development continued throughout adulthood. Now we discover it is also an essential source of well-being in midlife. Trust in self-help is what makes self-help effective. People have
more control than they realize over their physical health, their emotions, and possibly the structure of their brains—and the very awareness of that control is in itself a significant mainspring of happiness.