The ex-pat effect: presence of recent Western immigrants is associated with changes in age at first birth and birth rate in a Maya population from rural Guatemala

Abstract

Background: Economic transitions expose indigenous populations to a variety of ecological and cultural challenges, especially regarding diet and stress. These kinds of challenges are predicted by evolutionary ecological theory to have fitness consequences (differential reproduction) and, indeed, are often associated with changes in fertility dynamics. It is currently unclear whether international immigration might impact the nature of such an economic transition or its consequences for fertility.

Aim: To examine measures of fertility, diet and stress in two economically transitioning Maya villages in Guatemala that have been differentially exposed to immigration by Westerners.

Subjects and methods: This study compared Maya women’s ages at first birth and birth rates between villages and investigated whether these fertility indicators changed through time. It also explored whether the villages differed in relation to diet and/or a proxy of stress.

Results: It was found that, in the village directly impacted by immigration, first births occurred earlier, but birth rate was slower. In both villages, over the sampled time window, age at first birth increased, while birth rate decreased. The villages do not differ significantly in dietary indicators, but the immigration-affected village scored higher on the stress proxy.

Conclusion: Immigration can affect fertility in host communities. This relationship between immigration and fertility dynamics may be partly attributable to stress, but this possibility should be evaluated prospectively in future research.

Keywords:

• Fertility
• market integration
• immigration
• Maya
• behavioural ecology

Acknowledgements

We are so deeply grateful to the women who made the field portion of this project possible—our dedicated, thoughtful, driven field research assistants and the study participants who generously and patiently sat through long interviews regarding their birth histories, their livelihoods, and their families. We thank also Dr Mayron Martinez, Director of the VII Health Region in Sololá, Guatemala, and the Health Region’s staff for their support. Additionally, we thank Dr Nicole Berry (SFU), members of SFU’s Human Evolutionary Studies Program and of SFU’s Maternal and Child Health Lab, the editors of this special issue on the Human Biology of Migration, and three anonymous reviewers for thoughtful comments offered during the preparation of this manuscript. Lastly, we thank our funders: we received financial support for this work from the Social Sciences and Humanities Research Council of Canada, the Natural Sciences and Engineering Research Council of Canada, the Canada Research Chairs Program, the British Columbia Knowledge Development Fund, the Canada Foundation for Innovation, the Michael Smith Foundation, and Simon Fraser University.

Disclsoure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper

Additional information

Funding

This work was directly supported by a doctoral fellowship awarded to LM by the Social Sciences and Humanities Research Council of Canada (award: CGS-727-2011-3333) and by the Human Evolutionary Studies Program, sponsored by SFU's Endowment Fund.