Abstract

The myth of true, lifelong love promoted low divorce rates among farmers who depended on each other for survival. In the urban ecology after industrialization, it became increas­ingly clear that long-term monogamy goes against human nature. In the Scandinavian Modern Breakthrough, a late-1800s literary movement, Henrik Ibsen, August Strindberg, and others clashed in a battle over modern mating morality. Each interpreted Darwin to fit their own agenda, suggesting naturalistic understandings of “free love” and “true mar­riage,” some of which were laughable while others landed authors in prison. Evolutionary theory from our present era suggests that human mate choice is guided by three brain systems: erotic lust, romantic love, and feelings of deep attachment; our species thus evolved for serial pair-bonding with extra-pair copulation. Using these and other evolutionary insights, this article evaluates narratives from the Modern Breakthrough, which laid the foundation for today’s gender-equal and sexually liberal Nordic societies.