The researchers gauged study participants' mood before and after showing them a video clip - some saw a bit of a stand-up comedy routine, while others saw a video on how to install flooring.

Thee researchers gauged study participants' mood before and after showing them a video clip - some saw a bit of a stand-up comedy routine, while others saw a video on how to install flooring.

The researchers gauged study participants'mood before and after showing them a video clip - some saw a bit of a stand-up comedy routine, while others saw a video on how to install flooring.