Is Spring Fever Real? - Instant Egghead #68

A spring fever

that boost of energy,
vitality and sexual appetite

associated with spring.

It's been written about
for centuries.

but does it really exist?

There's definately something
in the springtime air

A Canadian study showed that

the rate of teen pregnancy
peaks in March.

Right around spring break.

And another found,
that men produce the most

and the healthiest sperm
in early spring.

What's causing this seasonal shift?

Scientists think, that our
increased energy and better mood

have to do with changes
in hormone levels.

An important one is melatonin

sometimes called the "sleep hormone"

It's realeased at night and
helps us fall asleep.

When the nights are longer

we produce more melatonin.

And in spring, as the nights get shorter,

we produce less of it.

Maybe explaining why we feel
more awake and more active.

Serotonin is another chemical
that affects our mood.

It's known as the "happiness hormone"

And its levels arise
in spring time as it gets sunnier.

Antrophologists think that
these changes in hormone levels

may have to do with
survival and reproduction.

Many animals lay low in the winter

using less energy because food is scarce.

Early humans might have done the same.

And when food became
more abundant in the spring,

it makes sense,
they become more... active.

Not surprisingly,
as you move toward the equator,

spring fever disappears.

For example, scientists have noticed

that seasonal changes in
the birth rates of field mice flatten out

as you get closer to the equator.

But sunshine may not be the only

springtime "pick-me-up".

For humans, the optimal temperature
for good mood is 72F.

And let's face it,

once the temperature starts to rise,

we're wearing a lot less.

For Scientific American's
Instant Egghead,

I'm Yasmin Tayag