Quantcast

<p>The United Nations declared March 20, 2014, the International Day of Happiness.<br /></p>

The United Nations declared March 20, 2014, the International Day of Happiness.

Stories this photo appears in:

Tease photo

Why happiness is healthy

A review of research found a link between well-being and heart health

Happiness -- you know it when you see it, but it's hard to define.