Book smarts vs. common sense - Intelligence thunderdome.

[Keyser Soze]

I often hear people say that so and so is relatively intelligent but lacks common sense.

How do you define common sense? Is it street smarts? The ability to read people?

Do you value book smarts more or common sense more?

I often find that people who are not very intelligent think they have tons of common sense by default, as if they are trying to compensate for being morons.