The symmetrical, scalloped, exuberant heart is everywhere: it gives shape to candy and candy boxes, cookies and cakes, earrings and pendants, floral arrangements, jewelry containers, vases, soaps, padlocks, and frothy milk on top of a cup of coffee. We see it used as a verb on t-shirts ("I <3 New York") and in text messages (the incredible variety of heart emojis). In all of its forms, and across borders, continents, and languages, the heart symbol conveys one thing, and one thing only: love.

Marilyn Yalom is a senior scholar at the Clayman Institute for Gender Research at Stanford University, and the author of A History of the Wife, among other books. She lives in Palo Alto, CA, with her husband, Irvin.