%0 Journal Article %A Miu, Elena %A Colleran, Heidi %+ Lise Meitner Research Group BirthRites - Cultures of Reproduction, Max Planck Institute for Evolutionary Anthropology, Max Planck Society Lise Meitner Research Group BirthRites - Cultures of Reproduction, Max Planck Institute for Evolutionary Anthropology, Max Planck Society %T Female friendship and the cultural transmission of low-fertility values: Evidence from rural Poland (advance online) : %G eng %U https://hdl.handle.net/21.11116/0000-0010-FE48-0 %R 10.1093/pnasnexus/pgaf113 %7 2025-04-05 %D 2025 %8 05.04.2025 %* Review method: peer-reviewed %X Understanding how demographic and cultural change interact is essential for understanding the trajectory of historical and contemporary societies. While the diffusion of low fertility values is thought to be a key process in the demographic transition, we lack a mechanistic understanding that can provide links between population-level transmission rates and individual characteristics. Here we examine whether compositional changes in personal support networks can shape the spread of low fertility norms and ultimately fertility outcomes. Using detailed demographic and relational data from 22 mid-transition communities in rural Poland, we show how social support partners affect key reproductive attitudes and values through shifts from kin- to non-kin-oriented friendships, and from instrumental to emotional support. This shift in friendship styles appears to be driven by educated women, who exchange more emotional support with friends, and who nominate fewer kin. This altered friendship composition and emotional support type is associated with low-fertility attitudes and outcomes among both post-reproductive and younger women. We identify emotional support as a key moderator of ideational change in the domain of fertility norms, with implications for cultural change more broadly. %K Anthropology (Biological, Health, and Medical Sciences)Demography %J PNAS Nexus %] pgaf113 %I Oxford University Press %C Oxford %@ 2752-6542