Untangling the biologic and social causes of low fertility in modern societies

Introduction

High-income countries are experiencing both unprecedentedly low and increasingly polarized fertility with growing social gradients in childbearing. Key theories on fertility patterns are based on the empirical observation that until recently fertility remained comparatively high in gender-egalitarian countries with strong support for families. Since 2010, many of the countries that provided evidence for such theories have reached record-low fertility. This confronts the scientific paradigm of the key drivers of fertility.

Research Objectives

BIOSFER investigates how social, biological, and psychological factors work together to produce the observed patterns, levels, and variation in fertility among young adults. It aims to determine to what extent the fertility decline and the related polarization can be attributed to social vs. biomedical factors.

Methodology

Our multi-theory approach leverages ideas from several disciplines and proposes that the existing theories must be complemented with concepts of:

1. Risk aversion and information
2. Intergenerational transmission of fecundity
3. Epigenetics and beyond

This is necessary in order to understand modern fertility behavior. We develop theoretically informed, falsifiable hypotheses that we test against the two richest population-based longitudinal pregnancy and pubertal cohorts in the world: MoBa in Norway and the DNBC in Denmark.

Approach

We offer a uniquely integrative life-course-based approach that is neither social nor biomedical, but combines central ideas from both. This approach evaluates the biosocial determinants of the key transition points from fetal life through puberty and partnering into:

• Planned childbearing
• Unplanned childbearing
• Partnered childbearing
• Unpartnered childbearing

Areas of Study

We study the social, biomedical, and psychological forces, their interactions, and intergenerational forces as they operate throughout the life-course to produce the modern low-fertility landscape.

Expected Outcomes

The results will help to provide a novel, bio-social framework for understanding the life-course processes that drive contemporary fertility patterns.