Sociologists of marriage and the family have generally treated love as a heterosexual, romantic, and marital phenomenon. They have approached it from a microsocial perspective, and have tended to define it in psychological terms. Love has rarely been considered a core concept in sociological theorizing. In this paper, I outline a macrosociological perspective on love that lends itself to an evolutionary interpretation. I explore the implications of the conceptualization of love as a social fact for theorists concerned with the conditions which facilitate sociocultural evolution and human development. Humanistic perspectives on love developed primarily by psychologists are, I suggest, compatible with recent developments in evolutionary theory regarding the importance of cooperation. Sorokin's speculations on the power of love are discussed as anticipations of the more systematic treatment carried out by more recent investigators. Love manifests the function of intimacy as a factor in facilitating information exchange and learning. This idea leads to the notion that love—appropriately conceived—is an evolutionary mechanism. Love may be a manifestation of a critical cooperative factor needed to solve emerging problems of individual and collective survival and growth. These problems are new in type and scale. There is a link, I argue, between love and the global political, economic, and general cultural imperatives of our time. The recognition and analysis of this link can, I suggest, improve our understanding of contemporary society in evolution.