Quiet: The Power of Introverts in a World That Can\'t Stop Talking pdfdrive com

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BEYOND TEMPERAMENT
The Role of Free Will (and the Secret of Public Speaking
for Introverts)
Enjoyment appears at the boundary between boredom and anxiety, when the challenges are
just balanced with the person’s capacity to act
.
—
MIHALY CSIKSZENTMIHALYI
Deep inside the bowels of the Athinoula A. Martinos Center for
Biomedical Imaging at Massachusetts General Hospital, the hallways are
nondescript, dingy even. I’m standing outside the locked door of a
windowless room with Dr. Carl Schwartz, the director of the
Developmental Neuroimaging and Psychopathology Research Lab.
Schwartz has bright, inquisitive eyes, graying brown hair, and a quietly
enthusiastic manner. Despite our unprepossessing surroundings, he
prepares with some fanfare to unlock the door.
The room houses a multimillion-dollar fMRI (functional magnetic
resonance imaging) machine, which has made possible some of the
greatest breakthroughs in modern neuroscience. An fMRI machine can
measure which parts of the brain are active when you’re thinking a
particular thought or performing a specific task, allowing scientists to
perform the once unimaginable task of mapping the functions of the
human brain. A principal inventor of the fMRI technique, says Dr.
Schwartz, was a brilliant but unassuming scientist named Kenneth
Kwong, who works inside this very building. This whole place is full of
quiet and modest people doing extraordinary things, Schwartz adds,
waving his hand appreciatively at the empty hallway.
Before Schwartz opens the door, he asks me to take off my gold hoop
earrings and set aside the metal tape recorder I’ve been using to record
our conversation. The magnetic field of the fMRI machine is 100,000

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times stronger than the earth’s gravitational pull—so strong, Schwartz
says, that it could rip the earrings right out of my ears if they were
magnetic and send them flying across the room. I worry about the metal
fasteners of my bra, but I’m too embarrassed to ask. I point instead to
my shoe buckle, which I figure has the same amount of metal as the bra
strap. Schwartz says it’s all right, and we enter the room.
We gaze reverently at the fMRI scanner, which looks like a gleaming
rocketship lying on its side. Schwartz explains that he asks his subjects—
who are in their late teens—to lie down with their heads in the scanner
while they look at photographs of faces and the machine tracks how
their brains respond. He’s especially interested in activity in the
amygdala—the same powerful organ inside the brain that Kagan found
played such an important role in shaping some introverts’ and
extroverts’ personalities.
Schwartz is Kagan’s colleague and protégé, and his work picks up just
where Kagan’s longitudinal studies of personality left off. The infants
Kagan once categorized as high-and low-reactive have now grown up,
and Schwartz is using the fMRI machine to peer inside their brains.
Kagan followed his subjects from infancy into adolescence, but Schwartz
wanted to see what happened to them after that. Would the footprint of
temperament be detectable, all those years later, in the adult brains of
Kagan’s high-and low-reactive infants? Or would it have been erased by
some combination of environment and conscious effort?
Interestingly, Kagan cautioned Schwartz against doing the study. In
the competitive field of science research, you don’t want to waste time
conducting studies that may not yield significant findings. And Kagan
worried that there were no results to be found—that the link between
temperament and destiny would be severed by the time an infant
reached adulthood.
“He was trying to take care of me,” Schwartz tells me. “It was an
interesting paradox. Because here Jerry was doing all these early
observations of infants, and seeing that it wasn’t just their social
behavior that was different in the extremes—everything about these kids
was different. Their eyes dilated more widely when they were solving
problems, their vocal cords became more tense while uttering words,
their heart rate patterns were unique: there were all these channels that
suggested there was something different physiologically about these

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kids. And I think, in spite of this, because of his intellectual heritage, he
had the feeling that environmental factors are so complex that it would
be really hard to pick up that footprint of temperament later in life.”
But Schwartz, who believes that he’s a high-reactive himself and was
drawing partly on his own experience, had a hunch that he’d find that
footprint even farther along the longitudinal timeline than Kagan had.
He demonstrates his research by allowing me to act as if I were one of
his subjects, albeit not inside the fMRI scanner. As I sit at a desk, a
computer monitor flashes photos at me, one after another, each showing
an unfamiliar face: disembodied black-and-white heads floating against a
dark background. I think I can feel my pulse quicken as the photos start
coming at me faster and faster. I also notice that Schwartz has slipped in
some repeats and that I feel more relaxed as the faces start to look
familiar. I describe my reactions to Schwartz, who nods. The slide show
is designed, he says, to mimic an environment that corresponds to the
sense that high-reactive people get when they walk into a crowded room
of strangers and feel “Geez! Who are these people?”
I wonder if I’m imagining my reactions, or exaggerating them, but
Schwartz tells me that he’s gotten back the first set of data on a group of
high-reactive children Kagan studied from four months of age—and sure
enough, the amygdalae of those children, now grown up, had turned out
to be more sensitive to the pictures of unfamiliar faces than did the
amygdalae of those who’d been bold toddlers. Both groups reacted to the
pictures, but the formerly shy kids reacted more. In other words, 
the
footprint of a high-or low-reactive temperament never disappeared in
adulthood
. Some high-reactives grew into socially fluid teenagers who
were not outwardly rattled by novelty, but they never shed their genetic
inheritance.
Schwartz’s research suggests something important: we can stretch our
personalities, but only up to a point. Our inborn temperaments influence
us, regardless of the lives we lead. A sizable part of who we are is
ordained by our genes, by our brains, by our nervous systems. And yet
the elasticity that Schwartz found in some of the high-reactive teens also
suggests the converse: we have free will and can use it to shape our
personalities.
These seem like contradictory principles, but they are not. Free will
can take us far, suggests Dr. Schwartz’s research, but it cannot carry us

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infinitely beyond our genetic limits. Bill Gates is never going to be Bill
Clinton, no matter how he polishes his social skills, and Bill Clinton can
never be Bill Gates, no matter how much time he spends alone with a
computer.
We might call this the “rubber band theory” of personality. We are
like rubber bands at rest. We are elastic and can stretch ourselves, but
only so much.
To understand why this might be so for high-reactives, it helps to look at
what happens in the brain when we greet a stranger at a cocktail party.
Remember that the amygdala, and the limbic system of which it’s a key