The 13th-century French manuscript "Romance of the Pear" contains an early depiction of the heart as a symbol of love. Allegorical image from the Roman de la poire. Image courtesy of Bibliothèque ...

They are plastered all over candy and billboards. They're everywhere on social media and throughout pop culture. From jewelry to emojis, the heart icon has symbolized love for centuries. But why?

Valentine’s Day is once again upon us. In 2006, Keelin McDonell attempted to track down the origin of the holiday’s heart-symbol to explain how it got its familiar shape. Her article is reprinted ...

Download the MP3 audio version of this story here, or sign up for the Explainer’s free daily podcast on iTunes. Americans will dole out countless Valentine’s Day paraphernalia today, a good portion of ...