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Implication of two-tiered life-history model for contemporary fertility trends in modern societies

Published online by Cambridge University Press:  11 November 2025

Ying Sun Open the ORCID record for Ying Sun [Opens in a new window]
Ying Sun*
Affiliation:
Department of Maternal, Child & Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui Province, China yingsun@ahmu.edu.cn
*
*Corresponding author.
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Abstract

The two-tiered model proposed by Ellis et al. offers a compelling framework for understanding how extrinsic mortality (EM) sources shape life history strategies, including fertility. This commentary evaluates this model in light of modern fertility trends, identifies gaps in its current formulation, and proposes modifications to enhance its explanatory power in modern contexts.

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Type
Open Peer Commentary
Information
Behavioral and Brain Sciences , Volume 48 , 2025 , e124
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Copyright
© The Author(s), 2025. Published by Cambridge University Press

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Footnotes

Two tiers, not one: Different sources of extrinsic mortality have opposing effects on life history traits.

References

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