One of my favorite end-of-relationship studies is by the sociologist Diane Felmlee. She asked people what had initially attracted them to an ex and what repelled them at the end. For about 30 percent of people, both answers were really the same, just cast in a very different light.

By “styles of loving” I am referring to the models used in “love research.” The broad concept “love” is sorted into a variety of baskets, such as responsible altruistic caretaking (agape), practical partnership (pragma), erotic intimacy (eros), and so on.