Love is confusing. People in the U.S. Google the word “love” about 1.2 million times a month. Roughly a quarter of those searches ask “what is love” or request a “definition of love.” What is all this ...

For millennia, philosophers, prophets, and poets have debated and theorized about love: what it is, how to describe it, how to cultivate it. Scientists, not so much. Indeed, only in recent decades ...