Both in everyday life and scholarly discourse, monogamists and polyamorists tend to unfavorably portray one another as somehow flawed, misguided, or, in a word, “inferior.” This article documents and critically examines two pairs of interlocked psychosocial attitudes—monopride/polyphobia and polypride/monophobia—mediating this predicament of mutual competition in the context of Western mononormative culture. The ideological nature of these “mono–poly wars” is demonstrated through a brief review of empirical literature on the psychological health and relationship quality of monogamous and polyamorous individuals and couples. The article concludes by outlining a critical pluralist approach that eschews universalizing hierarchies between monogamy and polyamory, and provides tools for making qualitative distinctions within and among relational styles.