Do immigrants have more children than people who were born in their destination country? Does immigrant childbearing behaviour adapt towards destination childbearing norms? In a new case study, Ben Wilson uses highly detailed administrative data for the whole population of Sweden to study how immigrants adapt their fertility.
For more than 100 years, research has debated whether immigrants adapt their behaviour after arrival in a new destination, and whether adaptation is intergenerational (Alba and Nee 1997). This would be the case, for example, if children of immigrants are closer to average patterns of behaviour (i.e. destination behavioural norms) as compared with their parents (Portes and Rivas 2011).
Prior research on adaptation includes many studies of childbearing (Kulu et al. 2019). Over the last few decades, there has been a lot of research about the childbearing of immigrants in high-income countries (Kulu et al. 2019). Some of this research has focused on Sweden (Mussino et al. 2021), which is an interesting country to study because it not only has a long history of receiving immigrants from a diverse range of countries, but also possesses high-quality data that allows them to be followed over the course of their lives.
Until now, most of what we know about the childbearing of immigrants has been based on studies of foreign-born women who migrated as adults (Kulu et al. 2019). Much less is known about male immigrants, or immigrants who arrived as children, despite the importance of studying these groups in order to understand how migration and parenthood are interlinked (Saarela and Wilson 2022).
Longer stay favours adaptation
In a recent article (Wilson 2025), I addressed this gap with a comprehensive case study of Sweden, covering the years 1968-2017. In summary, the study shows that immigrants are more likely to adapt to Swedish childbearing norms if they stay longer in Sweden. In the first stage of my analysis, I confirm that immigrants who arrive as adults often have different childbearing patterns from the average exhibited by Swedish-born individuals with Swedish-born parents. However, immigrants who arrived as children are much closer to the Swedish norm, and this remains broadly the case irrespective of their country of birth or their gender (Figure 1).
The study also finds that the childbearing of immigrants who came to Sweden as children depends upon their age at arrival. Those who arrived as infants tend to be much more likely to adapt to Swedish childbearing norms than those who arrived as teenagers. This is true for both women and men, in particular immigrants from higher fertility origins, although there is no material evidence of a critical arrival age that determines a step-change in future childbearing.
As well as generating a new understanding of the links between age at arrival and future childbearing, the study also innovates by implementing statistical methods – within family comparisons – not previously used to study this topic. These methods help to add certainty to the conclusions and confirm that the link between age at arrival and parenthood remains even if we compare siblings, who share many similar characteristics including the country they migrated from and the reasons for their migration (Figure 2).
Discussion and conclusions
The analysis also highlights the need to be careful about overgeneralising these findings. It shows, for instance, that the linkages between age at arrival and parenthood are neither ubiquitous nor homogenous. For example, age at arrival is more positively associated with completed fertility for childhood immigrants from high fertility origins. Yet even for this group, the precise nature of the relationship is diverse, and varies according to the interaction between age, sex, country of origin, and year of birth.
Thanks to its comprehensive analysis and detailed findings, this case study provides evidence of an underlying process of childhood socialization, followed by adaptation towards destination-country fertility norms, commonly observed among women and men who migrate.
Acknowledgements
The study is funded with support from the European Research Council (948727), the Swedish Research Council (VR), the Swedish Research Council for Health, Working life and Welfare (FORTE) and Riksbankens Jubileumsfond (RJ).
References
Alba, R., & Nee, V. (1997). Rethinking Assimilation Theory for a New Era of Immigration. International Migration Review 31(4), 826–874. https://doi.org/10.2307/2547416
Kulu, H., Milewski, N., Hannemann, T., & Mikolai, J. (2019). A decade of life-course research on fertility of immigrants and their descendants in Europe. Demographic Research 40, 1345–1374. https://doi.org/10.4054/DemRes.2019.40.46
Mussino, E., Wilson, B., & Andersson, G. (2021). The Fertility of Immigrants From Low-Fertility Settings: Adaptation in the Quantum and Tempo of Childbearing? Demography 58(6), 2169–2191. https://doi.org/10.1215/00703370-9476273
Portes, A., & Rivas, A. (2011). The Adaptation of Migrant Children. The Future of Children 21(1), 219–246. https://doi.org/10.1353/foc.2011.0004
Saarela, J., & Wilson, B. (2022). Forced Migration and the Childbearing of Women and Men: A Disruption of the Tempo and Quantum of Fertility? Demography 59(2), 707–729. https://doi.org/10.1215/00703370-9828869
Wilson B. (2025) The Childbearing of Immigrants Who Arrived as Children: Understanding the Role of Age at Arrival for Women and Men, Demography 62 (1): 183–209. https://doi.org/10.1215/00703370-11790197