Secret Life of the Grown-Up Brain (7 page)

“Older people clearly showed preference in memory and attention for positive over negative,” Carstensen says.

Hints of this had been seen earlier. Some smaller studies, for instance, had shown that as we age, we remember and report more positive aspects of daily life. Asked about an apartment they’d seen, older people are more likely to first say something such as, “Oh, it had a really good kitchen,” rather than, “The closets were way too small.” As we get older, we report fewer bad moments from our days. And we’re much less likely to label a whole day as bad just because of one untoward incident.

“It’s not that people who are younger don’t see the positive,” says Susan Turk Charles, “but with younger people, the negative response is more at the ready. If you ask an older person what kind of day they had, they are more likely to say, ‘Oh I had a good day,’ and if you ask them if anything bad happened, they are much more likely to say no. But with younger people, it is the opposite; they are much more likely to say, ‘Oh I had a very, very bad day. I had a big fight with my parents.’ ”

So, why this emphasis on the good side in life as we get older? Carstensen asked herself that very question. And after much consideration, a deep look at the literature, and more groundbreaking research, she settled on the answer: The shift occurs as we age because it comes from aging itself.

In the 2003 study “Aging and Emotional Memory: The Forgettable Nature of Negative Images for Older Adults,” Carstensen wrote:

“Our research team has informally asked scores of older people how they regulate their emotions, particularly during difficult periods in their lives. Regularly, they responded with the answer: ‘I just don’t think about it [problem or worries].’ At first this statement seemed to offer little insight into how older adults were regulating their feelings; however, the consistency of their responses made us turn to the possibility that processing positive and negative information may vary as a function of age.”

The conclusion was not reached lightly. Rather it was based on a whole raft of studies that looked at the question from every conceivable angle. In science you don’t always find a line of studies that progresses step by step, asking the next most logical question. But in the series of elegant studies, Carstensen and her colleagues did just that.

In one, for example, Carstensen wondered whether people didn’t remember negative material as well simply because they ignored it altogether. But that was not it. Instead, the researchers found that if older people were presented with one image at a time, they looked at negative pictures even longer than positive ones, the same as younger people.

Then Carstensen and her team discovered another intriguing clue, zeroing in on choice. She found that even though we don’t ignore negative information in middle age, if we are given the choice—positive or negative—we choose to focus more on the good than on the bad. Middle-aged people, for instance, were much faster at picking out small details on a happy-looking face than on an unhappy one.

Could it be, then, that negative images are simply much harder to process as we age, so, if we have the choice, we head toward the happier pictures because of a lack of energy, perhaps? Not at all. As Charles says, negative information is “much, much more potent” and remains much easier for brains to recognize and process. We actually have to work harder to focus on the positive.

“The literature is very, very clear on how much more potent the negative is,” Charles says. “Even with rats, it only takes one bad thing, one shock or a bad taste in their food, and they will avoid that place or that food. It only takes one bad experience for them to learn. And it’s the same with humans. If I see four friends and they all say, ‘Boy, that is a great dress.’ And then I see one other friend and she says, ‘Boy, you really have put on weight,’ guess which comment I will remember? And even in marriages, studies have shown that it takes
five
positives combined with one negative before someone will consider their marriage a happy one. If you have only two positives and one negative, that negative will wipe out the positive and people will consider the marriage a bad one. Believe me, the negative is much more powerful than the positive.”

That means that even in middle age, our brains still register the bad things around us.

Okay, the researchers said, but maybe the part of the brain that responds to negative and threatening information—the amygdala—simply begins to wear out, so that no matter how potent the negative message, it doesn’t register as strongly. But in further studies, Mather found that as we age our brains respond just as robustly to threats, a clear sign that our amygdalae are holding their own, even as we get older.

So what was behind this? What could be the reason for what Carstensen and her team began to call “the positivity effect,” the increase in focus on the positive as we age? In the end, the researchers were left with only one real answer: We focus more on the positive as we age because we want to. It suits our goals and—though we do it without knowing we’re doing it—we make it our business to sort out life this way.

And it is not that our brain gets lazy and wants to live out its days in some happy haze. On the contrary, Mather found conclusively that it’s the best brains, the brightest brains, that have the most bias toward the positive.

And it might very well have to do with the least positive idea around—death. Carstensen believes that as we age we become much more aware that we have less time left in life—and it therefore becomes much more important for us to maintain emotional stability. One way to keep on an even keel is to steer clear of the bad and focus on the good. And, though we’re not aware of it, we manipulate both our attention and our memory to suit that goal.

When we are young, negative information is paramount. We need to learn what to watch out for—the negative. But as we get older—and certainly by middle age—we already have a lot of cautionary knowledge. At that point, we may choose to gloss over a glitch here and there to focus on what’s more important—regulating our emotions. And we do it because it’s what we need—and want—to do.

“Time perspective is the dominating force that structures human motivations and goals,” Carstensen says. “Humans have a conscious and subconscious awareness of their time left in life, and that perceived boundary on time directs attention to the emotionally meaningful aspects of life. When time is perceived as expansive, as it is in healthy young adults, goal striving and related motivation center around acquiring information. Novelty is valued and investments are made in expanding horizons. In contrast, when time is perceived as limited, emotional experience assumes primacy.

“When we are younger we orient toward the negative. When we are younger that information just has more value,” she adds. “But increasingly with age, we see a shift. And I think it is because this shift serves to regulate our emotions. It’s not that we are sitting around saying ‘I will not focus on the negative.’ It is not conscious. But it is not completely subconscious, either. I would say it is a motivated choice that we make because it is useful.”

None of this means that at middle age we’re in some blissful fog. If you, or someone you care about, has a serious setback, illness, or suffer from clinical depression, it’s unlikely that you’re at your most jolly, no matter what your age.

But the scientific findings have been remarkably consistent: Our middle-aged brains work incredibly hard to be enthusiastic about life, to see the good things—a trait that may be one of the biggest advantages a brain can have.

And the positive spin may have evolved because it works well for the species in general. There is a well-known thesis, sometimes called the “Grandmother Hypothesis,” that postulates that humans and primates that had helpful, living grandmothers in their group lived longer. As Carstensen sees it, grandmothers with a brighter outlook gave the group a greater ability to thrive and survive.

“There is a powerful role in being calm and positive as we age; if older people are like that, it can help to keep the group together,” Carstensen told me. “If you have strong negative reactions you might react too quickly and get too angry and that might not help. But if you have a grandmother who cares and is attached, perhaps the whole group will live longer. If that grandmother has an amygdala that allows her to be calmer . . . that might give everyone an advantage. It is cognition serving survival.”

There are hints, too, that the shift may involve more parts of the brain than just the amygdala—in particular, the frontal cortex, the region behind our foreheads that has grown huge in humans and helps us focus on what we want to focus on. In yet another clever experiment, Mather found that when she distracted older people, they no longer stressed the positive. That means that the part of the brain they used to deal with distraction, the frontal cortex, was distracted itself and could not help push attention toward the positive, even if that was what these older people, on some other level, wanted to do.

Other brain-scanning studies, too, show this in more detail. Joseph Mikels, at Cornell University, has found that older adults who emphasize the positive side of life the most also use their frontal cortex the most, in particular the section called the orbital frontal cortex, which has been linked to emotional regulation. In some cases, the amygdala may be able to do this on its own; in others, a healthy frontal cortex joins in to make sure it happens, which to Mikels is convincing evidence that “the positivity effect is regulatory in nature.”

As Mikels himself confesses, this thought “goes against the grain—some of my students don’t believe this, they say, ‘my grandmother is the grouchiest person I know,’ but then I ask them and they say, well, it’s true she is lonely—and that’s the reason.”

But if our health and living situation are good, we gradually gain a brighter perspective because the structure and leanings of our brains start to head us in that direction.

“This is not a result of older adults wearing rose-colored glasses, but a function of their brains, which they have activated, and regulated, to focus on the positive and away from the negative,” Mikels added. “We do it on some level on purpose. The ability to regulate emotions increases with age. This is one of the really good things about the middle-aged brain.”

4 Experience. Judgment. Wisdom.

Do We Really Know What We’re Talking About?

There’s an argument to be made that the true test of a human brain is its ability to figure out other human brains.

Not long ago, when I mentioned that I was writing a book about the middle-aged brain to a friend, her first question was about the younger, trainee brains she had at home. As a mother of three girls, all in adolescence, she wanted to know, in a wishful way, only one thing: Does judgment improve? Do we get better at dealing with other humans, at making the right call?

Yes—and such insight is rooted in brain biology. We can now detect—even watch—mature judgment grow in our brains. The connections that help us identify the bad guys or the wrong road get stronger, and they may be at their strongest at middle age.

Thomas Hess, a psychologist at North Carolina State University, has done dozens of studies of what he calls “social expertise,” which he finds peaks in midlife, when we are far better than those younger
and
older at judging the true character of others. Such tricky evaluations get easier—and closer to the mark—as we age. And it’s the nature of how our brains develop that gives us that advantage.

By middle age, we not only have more years of experience with real people in the real world but the brain cells devoted to navigating the human landscape turn out to be exceptionally durable. Scanning studies show that parts of the frontal cortex that deal more with emotional regulation atrophy less quickly than other brain sections as we age. And it’s that mix of emotional control, mental prowess, and life experience that helps us make the right calls.

“Some areas of the brain that appear to be involved in processing of socioemotional information . . . exhibit relatively less neuronal loss than other parts of the brain,” Hess told me. “As individuals progress through life, they interact with others and acquire culturally based knowledge [about] . . . why people behave the ways that they do.

“The fact that middle-aged adults appear to be the most expert is consistent with notions that midlife is a time of optimal functioning,” he added. “Basic cognitive abilities are still relatively high, and there’s also a fair amount of experience . . . [so they] function at high levels in everyday settings.”

And those everyday settings include a wide range of activities. David Laibson, at Harvard University, for example, has done fascinating studies in the emerging field of “neuroeconomics”—how people use their brains to make financial decisions—and he, too, finds we’re most adept at this in middle age. Laibson has found that when confronting complex money issues, such as mortgages or interest rates, those in middle age make the best choices. In studies around the world, Laibson has found that people roughly between the ages of forty and sixty-five more easily grasp the consequences of financial decisions and have better judgment overall.

In fact, Laibson goes so far as to pinpoint the apex of all this: His research finds that those who use the best judgment in matters of personal economics are in their fifties.

“That seems to be the sweet spot in terms of all this,” Laibson told me.

So what is this sweet spot? Is it judgment? Is it social expertise? Is this what we call wisdom?

The concept of wisdom—perhaps the most clichéd cliché of aging—has deep roots. It’s mentioned frequently throughout literature, notably in the Bible, where it’s described as a special mix of heart and mind. Most neuroscientists regard the concept with suspicion. Even now, those who will speak out loud about the idea divide into camps, albeit overlapping ones. Some assign wisdom’s weight to emotional equilibrium, beginning with William James’s famous declaration in 1890 that wisdom is “the art of knowing what to overlook.”