As the researchers had predicted, the polyamorists enjoyed more nurturance from their primary than from their secondary, partners, on average, and gave higher eroticism ratings to their secondary relationships. Overall, their eroticism ratings were higher than for the monogamists. More surprisingly, their nurturance ratings for their primary relationship were higher than those reported by the monogamists. These differences held even when the researchers controlled for the differences in relationship length between the two groups.

There were also some differences in sexual satisfaction and closeness. Among the monogamous participants, eroticism and nurturance were both positively associated with sexual satisfaction and closeness. For the polyamorists, nurturance was similarly linked to feelings of closeness in both their relationships, but eroticism was only associated with sexual satisfaction and closeness in their secondary relationships,

“These findings have broad research implications for the study of romantic relationships,” the researchers write. “The belief that monogamy is superior to other relationship orientations is a fundamental and often unquestioned assumption underlying contemporary theories of the development of romantic relationships and intimacy.” And