"Amatonormativity" is a relatively new term — coined about five years ago by Elizabeth Brake, an associate professor of philosophy at Arizona State University and the author of Minimizing Marriage — to capture two widely held assumptions. The first being a person who isn’t in a monogamous romantic relationship is seeking that type of relationship, and the second being a person would automatically be better off in a monogamous romantic relationship than he or she would be while single or in another type of relationship.
In a phone interview, Brake told me she modelled "amatonormativity" after the term "heteronormativity," or the belief heterosexuality is the default sexual orientation. ("Amatus" is the Latin word for "loved.") When the default assumption is that being in a committed relationship — any relationship, regardless of its quality — is prized above all else, it can leave some singles feeling singled out.