Baumard, N., Huillery, E., Hyafil, A. et al. (2022). The cultural evolution of love in literary history. Nature Human Behaviour, 6, 506–522. https://doi.org/10.1038/s41562-022-01292-z

Cultural historians know that the importance of love grew during the Medieval and Early Modern European periods. The phenomenon was labelled as the birth of “courtly love”. Recent studies, on the other hand, have shown that Chinese, Arabic, Persian, Indian, and Japanese cultures all follow the same pattern.

The authors explore in this article why such convergent evolution in such disparate cultures occurred. They use literary history to create a database of ancient literary fiction for 19 geographical places and 77 historical periods spanning 3,800 years, from the Middle Bronze Age to the Early Modern period. In their analyses, they employed qualitative and quantitative methodologies.

They first showed that romantic features have been more prevalent in Eurasian literary fiction over the last millennium and that similar increases happened in Ancient Greece, Rome, and Classical India. They then looked into the ecological factors that have contributed to this rise in the literary importance of romantic love. The results of their study have shown that a higher level of economic development is highly associated with a greater incidence of love in narrative fiction, which is consistent with ideas from cultural history and behavioural ecology.

The authors employed a difference-in-difference strategy that uses exogenous regional variations in economic growth coming from the adoption of the heavy plough in medieval Europe to further investigate the causal impact of economic development. Finally, they employed probabilistic generative models to recreate the latent evolution of love and assess the influence of cultural diffusion and economic development on this process.