Back at the University of Maryland,
infants are brought in at 9 months for
the second assessment of the temperament
study. This time researchers want to measure
the emotions of anger, joy, and fear. All aspects
of temperament. First, Jack is allowed to play
with a colorful toy. Then a transparent
barrier is put between him and the object
of his desire. He sees the toy but can't
reach it. No matter how frustrated Jack
feels he won't give up. And when he can't
do it on his own, he tries to charm the
researcher into helping him.
Emily, also 9 months, is of a different
temperament than Jack. It seems she's
more laid back. She gives it one or two
tries but then gives up.
And even when the researcher tries to
entice her again, she can't be bothered.
Everyone knows that a puppet show makes
children happy. During this part of the study,
researchers want to draw joy from the
babies. Emily loves the puppets and even
tries to join in on the action.
But when the researcher tries the same
experiment on Jack, he finds the situation
anything but joyful. His temperament is
such that he's easily frightened and he
will have none of it. The minute the puppets
are removed, he cheers up and is ready for
more action. Next researchers test the baby's
reaction when something frightens them.
Not surprisingly, Jack is shaken by the scary mask.
So they bring on the clown mask and this one
really pushes him past his limit.
But Emily is very interested. She finds the
clown amusing and thinks it's just a continuation
of the previous entertainment. As for the more
ominous mask, she just takes it in stride and
adopts a "wait and see" attitude. Why does
Emily react differently from Jack? Where
does the difference reside? To find out,
Dr. Peter Marshall places an EEG cap on
Emily. The electrodes on the cap will
measure the electrical signals produced
by her brain in response to a series of
sounds. A researcher distracts Emily
while they get a base line reading of her
brain. Then she hears a series of tones.
The series consists of regular beeps, interspersed
with other sounds that are different. How the
brain reacts to sudden new stimuli is recorded.
Emily seems to have more activity in her
right frontal lobe. This kind of reading is
associated with children who have a more
subdued personality. But what has fascinated
researchers is that babies with exuberant
temperaments show an exaggerated response
on the other side of the brain, in the left frontal lobe.
In test after test, this ground breaking research
has shed light on the neurobiological basis of
restraint and exuberance. Jack overreacts so much
that he won't even allow the cap to be put on.
One can only guess what the alpha waves in
his left frontal lobe are showing. But is emotional
temperament constant over time? Will the temperament
that Elizabeth exhibits at six months be the same
when she is older?
Will the curious toddler remain curious forever?
The lounger. The joker. The dreamer.
The industrious one. Are they destined to carry
these temperament traits into the years ahead?
And what about the worrier? And even the shy one?
To find out researchers at Nathan Fox's lab bring
back children previously tested for the final part
of the long term study. 24 month Ethan and his
mother are introduced to the risk room to see
how Ethan reacts to various stressful situations.
A stranger enters. In this first part of the study,
what researchers measure is how long it takes
for the child, if at all, to overcome shyness and
warm up to the stranger. Eventually, when the
so called stranger pulls out some inviting toys
Ethan overcomes his shyness and takes the risk.
Once he's comfortable with the stranger, they
continue with the next part of the study.
Researchers wanted to find out how children
react to unpredictable situations. And the
toy robot is certainly unpredictable with
its' noises and sudden movements.
The robot proves too much for Ethan,
even with his mother by his side.
For the next part of the study, Ethan
is tested on a set of stairs to see if he's a risk taker.
The researcher demonstrates and invites
Ethan to try. But Ethan is a cautious little boy.
One foot and then the other. He gets
over the hurdle in his own way. And boldened
by his success he does it again. Upon reflection,
he turns to his mother. He wants her to recognize
how big a risk he took. 24 month Raphael, who's
the same age as Ethan reacts differently. He's
a child who likes to take risks.
But when the robot arrives, he's not such
a hero. Unpredictable situations which he
has no control over terrify him.
35 month Abby has a totally different
temperament. She takes charge of the situation
and even gives instructions to the
researcher before leaping off the stairs.
When the robot appears, Abby is intrigued
but only up to a point. She needs to hold onto
the researcher for courage. The final part of this
study shows that the amount of risk a child
takes depends on their individual temperament.
And as researchers gather all the findings of this
long term study, they expect to find that children
who are at the temperamental extremes at 4 months
will demonstrate the same tendencies at 9 months
and 24 months. But does early temperament seal
the baby human's emotional fate? Will their childhood
temperament govern their behavior for life?