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?