Understanding the Anxious Mind
Jerome
Kagan’s “Aha!” moment came with Baby 19. It was 1989, and Kagan, a
professor of psychology at Harvard, had just begun a major longitudinal
study of temperament and its effects. Temperament is a complex,
multilayered thing, and for the sake of clarity, Kagan was tracking it
along a single dimension: whether babies were easily upset when exposed
to new things. He chose this characteristic both because it could be
measured and because it seemed to explain much of normal human
variation. He suspected, extrapolating from a study he had just
completed on toddlers, that the most edgy infants were more likely to
grow up to be inhibited, shy and anxious. Eager to take a peek at the
early results, he grabbed the videotapes of the first babies in the
study, looking for the irritable behavior he would later call
high-reactive.
No
high-reactors among the first 18. They gazed calmly at things that were
unfamiliar. But the 19th baby was different. She was distressed by
novelty — new sounds, new voices, new toys, new smells — and showed it
by flailing her legs, arching her back and crying. Here was what Kagan
was looking for but was not sure he would find: a baby who essentially
fell apart when exposed to anything new.
Baby
19 grew up true to her temperament. This past summer, Kagan showed me a
video of her from 2004, when she was 15. We sat in a screening room in
Harvard’s William James Hall — a building named, coincidentally, for the
19th-century psychologist who described his own struggles with anxiety as
“a horrible dread at the pit of my stomach ... a sense of the
insecurity of life.” Kagan is elfin and spry, balding and bespectacled.
He neither looks nor acts his age, which is 80. He is one of the most
influential developmental psychologists of the 20th century.
On
the monitor, Baby 19 is a plain-looking teenager, hiding behind her
long, dark hair. The interview, the same one given to all 15-year-olds
in the longitudinal study, begins with questions about school. She has
very few extracurricular activities, she says in a small voice, but she
does like writing and playing the violin. She fidgets almost constantly
as she speaks, twirling her hair, touching her ear, jiggling her knee.
“This is the overflow of her high-reactive nature,” Kagan told me,
standing near the monitor so he could fast-forward to the good parts.
“I
don’t know,” Baby 19 says after a long pause, twirling her hair faster,
touching her face, her knee. She smiles a little, shrugs. Another
pause. And then the list of troubles spills out: “When I don’t quite
know what to do and it’s really frustrating and I feel really
uncomfortable, especially if other people around me know what they’re
doing. I’m always thinking, Should I go here? Should I go there? Am I in
someone’s way? ... I worry about things like getting projects done... I
think, Will I get it done? How am I going to do it? ... If I’m going to
be in a big crowd, it makes me nervous about what I’m going to do and
say and what other people are going to do and say.” Baby 19 is wringing
her hands now. “How I’m going to deal with the world when I’m grown. Or
if I’m going to sort of do anything that really means anything.”
Her
voice trails off. She wants to make a difference, she says, and worries
about whether she will. “I can’t stop thinking about that.”
Watching
this video again makes Kagan fairly vibrate with the thrill of
rediscovery: here on camera is the young girl who, as an infant, first
embodied for him what it meant to be wired to worry. He went on to find
many more such children, and would watch a big chunk of them run into
trouble with anxiety or other problems as they grew up.
The
tenuousness of modern life can make anyone feel overwrought. And in
societal moments like the one we are in — thousands losing jobs and
homes, our futures threatened by everything from diminishing retirement
funds to global warming —
it often feels as if ours is the Age of Anxiety. But some people, no
matter how robust their stock portfolios or how healthy their children,
are always mentally preparing for doom. They are just born worriers,
their brains forever anticipating the dropping of some dreaded other
shoe. For the past 20 years, Kagan and his colleagues have been
following hundreds of such people, beginning in infancy, to see what
happens to those who start out primed to fret. Now that these infants
are young adults, the studies are yielding new information about the
anxious brain.
These
psychologists have put the assumptions about innate temperament on
firmer footing, and they have also demonstrated that some of us, like
Baby 19, are born anxious — or, more accurately, born predisposed to be
anxious. Four significant long-term longitudinal studies are now under
way: two at Harvard that Kagan initiated, two more at the University of
Maryland under the direction of Nathan Fox, a former graduate student of
Kagan’s. With slight variations, they all have reached similar
conclusions: that babies differ according to inborn temperament; that 15
to 20 percent of them will react strongly to novel people or
situations; and that strongly reactive babies are more likely to grow up
to be anxious.
They
have also shown that while temperament persists, the behavior
associated with it doesn’t always. Kagan often talks about the three
ways to identify an emotion: the physiological brain state, the way an
individual describes the feeling and the behavior the feeling leads to.
Not every brain state sparks the same subjective experience; one person
might describe a hyperaroused brain in a negative way, as feeling
anxious or tense, while another might enjoy the sensation and instead
uses a positive word like “alert.” Nor does every brain state spark the
same behavior: some might repress the bad feelings and act normally;
others might withdraw. But while the behavior and the subjective
experience associated with an emotion like anxiety might be in a
person’s conscious control, physiology usually is not. This is what
Kagan calls “the long shadow of temperament.” The oldest high-reactive
subjects in Kagan’s and Fox’s studies, like Baby 19, are in their 20s
now, and for many of them, no matter how much they manage to avoid
looking anxious to an outsider, fears still rattle in their skulls at 3
o’clock in the morning. They remain anxious just below the surface,
their subconscious brains still twitchy, still hypervigilant, still
unable to shift attention away from perceived threats that aren’t really
there.
ANXIETY IS NOT fear,
exactly, because fear is focused on something right in front of you, a
real and objective danger. It is instead a kind of fear gone wild, a
generalized sense of dread about something out there that seems menacing
— but that in truth is not menacing, and may not even be out there. If
you’re anxious, you find it difficult to talk yourself out of this
foreboding; you become trapped in an endless loop of what-ifs.
“I
was flesh bereft of spirit,” wrote the journalist Patricia Pearson in
“A Brief History of Anxiety (Yours and Mine),” in a pitch-perfect
description of this emotional morass, “a friable self, grotesque... I
got an AIDS test. I had my moles checked. I grew suspicious of pains in my back. If I was nauseous, I worried about cancer and
started reading up obsessively on symptoms. I lay in bed whenever I
could, trying to shut up the clamor of terror with sleep.”
When
the “clamor of terror” starts to interfere with functioning, as it did
for Pearson when she was a crime reporter in her early 30s, worrying
turns into a clinical anxiety disorder, of which there are several forms: panic, social anxiety, phobia, obsessive-compulsive, post-traumatic stress and a catch-all called generalized anxiety disorder.
Taken together, they make anxiety the most common mental illness in
America, affecting an estimated 40 million adults, according to the
National Institute of Mental Health. And that figure doesn’t even count
the far greater swath who are garden-variety worriers, people who fret
when a child is late, who worry when they hear a siren headed toward
home, who are sure that a phone call in the middle of the night means
someone is dead.
In
the brain, these thoughts can often be traced to overreactivity in the
amygdala, a small site in the middle of the brain that, among its many
other functions, responds to novelty and threat. When the amygdala works
as it should, it orchestrates a physiological response to changes in
the environment. That response includes heightened memory for
emotional experiences and the familiar chest pounding of fight or
flight. But in people born with a particular brain circuitry, the kind
seen in Kagan’s high-reactive study subjects, the amygdala is
hyperreactive, prickly as a haywire motion-detector light that turns on
when nothing’s moving but the rain. Other physiological changes exist in
children with this temperament, many of them also related to
hyperreactivity in the amygdala. They have a tendency to more activity
in the right hemisphere, the half of the brain associated with negative
mood and anxiety; greater increases in heart rate and pupil dilation in
response to stress; and on occasion higher levels of the stress
hormones cortisol and norepinephrine.
But
having all the earmarks of anxiety in the brain does not always
translate into a subjective experience of anxiety. “The brain state does
not make it a disorder,” Kagan told me. “The brain state exists, and
the statement ‘I’m anxious,’ exists, and the correlation is imperfect.”
Two people can experience the same level of anxiety, he said, but one
who has interesting work to distract her from the jittery feelings might
do fine, while another who has just lost his job spends all day at home
fretting and might be quicker to reach a point where the thrum becomes
overwhelming. It’s all in the context, the interpretation, the ability
to divert your attention from the knot in your gut. These variations
also happen when someone grows up from an anxious infant to someone
either fretful or tranquil. One aim of Kagan’s and Fox’s longitudinal
studies is to watch how the life stories of these high-strung babies
unfold.
The
quintessential longitudinal study, the one often mentioned because it
set the standard, is the Framingham Heart Study, which enshrined the
idea of risk factors. It was through Framingham, for instance, that
scientists learned that high blood pressure was
a risk factor for cardiovascular disease, since it followed its
subjects for long enough to detect that those who had high blood
pressure in their 30s and 40s were more likely to have heart disease
later in life.
But
such studies draw conclusions about trends, not destinies. If someone
with high blood pressure treats it early, the risk of heart disease can
be reduced significantly. Similarly, if someone with an anxiety-prone
temperament grows up in the right surroundings, he or she might never
develop a full-blown anxiety disorder.
Kagan’s
first exposure to longitudinal studies came shortly after he received
his Ph.D. from Yale in 1954. He was working at the Fels Research
Institute on the campus of Antioch College in Ohio, where a longitudinal
study of middle-class children had been going on for nearly 30 years.
He stumbled upon a gigantic room “loaded with prose summaries of what
these children were like from the age of 1 month on,” he told me
recently. He knew a treasure trove when he saw one.
Among
these prose summaries, which ultimately Kagan and a colleague, Howard
Moss, turned into the book “Birth to Maturity,” were descriptions
indicating that babies had different innate temperaments. Kagan
studiously ignored this finding; it didn’t fit with his left-leaning
politics, which saw all individuals as born inherently the same — blank
slates, to use the old terminology — and capable of achieving anything
if afforded the right social, economic and educational opportunities. “I
was so resistant to awarding biology much influence, I didn’t follow up
on the inhibited temperaments I was seeing,” he told me. It took
another 20 years of listening to arguments about nature versus nurture
for Kagan finally to entertain the possibility that some behavior might
be attributed to genes.
BY THE TIME Kagan
moved to Harvard in 1964, the notion of an inborn temperament was on
the ascent, in part because of the findings of Stella Chess and
Alexander Thomas of New York University, who divided children into three
categories: easy children, difficult children and those who were slow
to warm up. Remembering the Fels data, Kagan embarked on his own
longitudinal study of temperament. In 1979, he screened about 400
preschoolers, exposing them to new toys and new people in a laboratory
playroom, videotaping them and coding their behavior. About 15 percent
ended up in the group Kagan called “behaviorally inhibited”: wary,
subdued, tending to hover near their mothers. Another 15 percent were
“behaviorally uninhibited.” They were the fearless ones, who ran around
trying to play with every new toy and chatting happily with the
examiner. When Kagan talks about such children, he uses one of his
favorite words: “ebullient.”
Over
the next five years, 107 of these children — half of them timid, half
bold — came back to the lab for more testing. (To keep environmental
differences to a minimum, Kagan restricted his sample to children who
were white, middle class and healthy at birth.) Their behavior was again
recorded and again coded. Temperament, it turned out, tended to be
stable over those five years, at least in children who started out at
the extremes. There was a shift toward the middle between ages 2 and 7,
but only 3 of the 107 changed categories completely from uninhibited to
inhibited or vice versa. In addition, the most inhibited 7-year-olds
showed some physiological differences that indicated an exaggerated
response to stress.
Kagan
and his colleagues, Nancy Snidman and J. Steven Reznick, published
their results in Science in 1988. The physiological measurements led
them to believe something biological was at work. Their hypothesis: the
inhibited children were “born with a lower threshold” for arousal of
various brain regions, in particular the amygdala, the hypothalamus and
the hypothalamic-pituitary-adrenal axis, the circuit responsible for the
stress hormone cortisol.
Though
its findings seem almost self-evident today, the Science paper made a
splash at the time. “There are two kinds of great research,” Susan
Engel, a developmental psychologist at Williams College, told me when I
discussed Kagan’s study with her. “There’s research that is
counterintuitive, that shows you something you’d never guess on your
own, and there’s research that shows you irrefutably what you had an
intuition about, something you thought was true but didn’t have evidence
to support.” Kagan’s research was of the second type, she says: “a
beautiful, elegant experimental demonstration of an old intuition.”
But
these subjects were preschoolers when Kagan first met them, already too
old for him to know how much to attribute to nature rather than
nurture. Couldn’t the inhibited children somehow have been raised to be
wary instead of born that way? So the following year, Kagan began a new
study he said he hoped would minimize the effects of the environment. He
recruited infants who were just 4 months old, planning to categorize
them according to temperament and to follow them as they grew to see
whether temperament in infancy predicted anything about subsequent
personality.
How
to measure temperament in babies so young, at an age when some parents
are still wondering whether a smile means happiness or gas? Kagan
couldn’t measure the amygdala directly, so he looked for signs of its
rampant firing that would be meaningful — and measurable — in infants.
Since projections from the amygdala connect it to brain regions that
control motor activity and the autonomic nervous system (heartbeat,
breathing and other involuntary actions), he reasoned that if the
amygdala was highly reactive, it would show up as increased motor
activity, fretting and crying, as well as increases in heart rate,
respiration and blood pressure.
Showing
that a few physical measurements could offer insight into a baby’s
psyche was one of Kagan’s real contributions. “Where his work had so
much depth was not only in the longitudinal follow-up,” says Joan
Kaufman, a Yale psychologist who was a research assistant at Harvard
when the study began, “but in thinking about the behavioral phenotype of
an inborn temperament and really assessing it with such rigor.”
Kagan
brought about 500 babies — as before, all white, middle class and
healthy — into the laboratory, placed them in infant seats in front of a
video camera and exposed them to a series of novel stimuli. He showed
them a schematic face that emitted words in a synthetic voice designed
to be what he called “discrepant but not terrifying.” He dangled a
dancing mobile with plastic Winnie the Pooh characters — again, nothing
scary, but something new. He brought to their noses a cotton swab that
had been dipped in diluted alcohol. The battery of novel stimuli took 45
minutes. Some of the babies gazed contentedly throughout. Others were
in constant motion, kicking and moving their arms fitfully, furrowing
their brows, arching their backs or crying if they were really upset.
Kagan
and his research assistants again looked at videotapes and coded
movements and cries. Based on the final tally, each infant was
categorized as either low-reactive, high-reactive or somewhere in
between. The low-reactives were the classic easy babies, the ones who
take unfamiliarity in stride. The high-reactives, among them Baby 19,
thrashed and whimpered when exposed to the same unfamiliar things. It
was clear, as they twisted about in their infant seats, that these
babies were high-maintenance, difficult to comfort.
About
40 percent were low-reactive, and about 20 percent were high-reactive.
Kagan brought most of them, as well as those with intermediate
temperament, back for testing at ages 1 and 2. About half of them —
primarily those at each extreme — returned for further testing at ages
4, 7, 11 and 15. That pattern continues to this day, even after Kagan
retired in 2000 and handed over his records to a collaborator, Carl
Schwartz, an adolescent psychiatrist at Harvard and Massachusetts
General Hospital, who tested some of Kagan’s subjects when they were 18
or 21.
By
the earliest assessments, certain patterns had already emerged. At age
4, children who had been high-reactive were four times as likely to be
behaviorally inhibited as those who had been low-reactive. By age 7,
almost half of the jittery babies had developed symptoms of anxiety —
fear of thunder or dogs or darkness, extreme shyness in the classroom or
playground — compared with just 10 percent of the more easygoing ones.
About one in five of the high-reactive babies were consistently
inhibited and fearful at every visit up to the age of 7.
“Fear
is an incredibly heterogeneous construct,” says Daniel Pine, a child
psychiatrist at the National Institute of Mental Health. Pine
collaborates on the two longitudinal studies at the University of
Maryland, conducting psychiatric interviews and functional M.R.I. scans
on subjects at several stages. “Fear of social things is different from
fear of physical things.” The same brain circuitry is probably involved
in both, he said, but different fears tend to show up at different
points in development: fear of things like clowns, balloons or spiders
emerging early in life; fear of things like social situations with peers
emerging later. In addition, it’s relatively easy to avoid the physical
things that frighten you; if you’re afraid of dogs, you can just take a
different route to school to keep from passing that bull terrier down
the street. It’s much harder to avoid social fears — you can avoid the
dog on the way to school, but you still have to go to school.
The children tended to get a better grip on their fearfulness as they got older. By adolescence,
the rate of anxiety in Kagan’s study subjects declined overall,
including in the high-risk group. At 15, about two-thirds of those who
had been high-reactors in infancy behaved pretty much like everybody
else.
One
such person was Mary, now a 21-year-old junior at Harvard, who was in
the high-reactive group as a baby and was moderately fearful at ages 1
and 2. She didn’t think of herself as anxious, just dutiful. “I don’t
stray from the rules too much,” she said when we spoke by telephone not
long ago. “But it’s natural for me — I never felt troubled about it. I
was definitely the kid who worked really hard to get good grades, who
got all my homework done before I watched TV.” Mary also was an
accomplished ballet dancer as a child, which gave her a way to work off
energy and to find a niche in which she excelled. That talent, plus
being raised in what Kagan called a “benevolent home environment,” might
have helped shift Mary’s innate inhibition to something more
constructive. If Mary’s high-reactive temperament is evident now, it
comes out in the form of conscientiousness and self-control.
PEOPLE WITH A nervous
temperament don’t usually get off so easily, Kagan and his colleagues
have found. There exists a kind of sub-rosa anxiety, a secret stash of
worries that continue to plague a subset of high-reactive people no
matter how well they function outwardly. They cannot quite outrun their
own natures: consciously or unconsciously, they remain the same uneasy
people they were when they were little.
Most
of the high-reactive kids in Kagan’s study did well in adolescence,
getting good grades, going to parties, making friends. Scratch the
surface, though, and many of them — probably most of them — were buckets
of nerves. “It’s only the high-reactives who say, ‘I’m tense in
school,’ ‘I vomit before examinations,’ ‘If we’re going on a class trip
to D.C., I can’t sleep the night before,’ ” Kagan told me. “They don’t
like it, but they’ve accepted the fact that they’re just tense people.”
Invoking Jungian terminology, he called it the difference between
persona (the outer-directed personality) and anima (the inner-directed
thoughts and feelings). The persona can be controlled, but the anima
often cannot.
Nathan
Fox of the University of Maryland says that when the anima erupts in
high-risk children, it often takes the form of excessive vigilance and
misdirected attention. In the first of his two longitudinal studies of
temperament, begun in 1989, he followed 180 children from the age of 4
months and gave them a set of neuropsychological tests when they were
between 13 and 15. One test, called the spatial-cuing task, measures
vigilance and the ability to disengage attention from a perceived
threat. It shows two faces briefly on a computer screen, one on each
side — the same face looking threatening on one side and pleasant on the
other. The faces fade away, and an arrow appears on one side of the
screen, sometimes on the side the threatening face had been on,
sometimes on the other. The subject must notice the arrow and press a
button to indicate whether the arrow points up or down.
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