Narrator: Now, listen to part of a lecture in a psychology class.

Professor: Why do we do the things we do?

What drives us to participate in certain activities,

to buy a certain car or even to choose a certain career?

In other words, what motivates us to do what we do?

Well, in studies of motivation,

psychologists distinguish between two very different types.

Our reasons for doing something, our motivations, can be extrinsic,

in other words, based on some kind of external reward,

like praise or money.

Or they can be intrinsic,

meaning we engage in the activity because it pleases us internally.

Both create strong forces that lead us to behave in certain ways.

However, intrinsic motivation is generally considered to be more long lasting than the other.

As I said,

extrinsic motivation is external.

It's the desire to behave in a certain way in order to obtain some kind of external reward.

A child, for example,

who regularly does small jobs around the house,

does them not because she enjoys taking out the garbage or doing the dishes,

but because she knows if she does these things,

she'll be given a small amount of money for doing them.

But how motivated will the child be to continue doing the work,

if her parents suddenly stopped giving her money for it?

With intrinsic or internal motivation,

we want to do something because we enjoy it or get a sense of accomplishment from it.

Most people who were internally motivated get pleasure from the activity, so they just feel good about doing it.

For example, I go to the gym several times a week.

I don't go because I'm training for a marathon or anything.

I just enjoy it.

I have more energy after I exercise,

and I know it's good for my health,

so it makes me feel good about myself,

and that's what's kept me going there for the past five years.