TY - JOUR
T1 - Increasing Population Densities Predict Decreasing Fertility Rates Over Time
T2 - A 174-Nation Investigation
AU - Rotella, Amanda
AU - Varnum, Michael E.W.
AU - Sng, Oliver
AU - Grossmann, Igor
N1 - Publisher Copyright:
© 2021. American Psychological Association
PY - 2021
Y1 - 2021
N2 - Fertility rates have been declining worldwide over the past 50 years, part of a phenomenon known as “the demographic transition.” Prior work suggests that this decline is related to population density. In the present study, we draw on life history theory to examine the relationship between population density and fertility across 174 countries over 69 years (1950 to 2019). We find a robust association between density and fertility over time, both within and between-countries. That is, increases in population density are associated with declines in fertility rates, controlling for a variety of socioeconomic, socioecological, geographic, population-based, and female empowerment variables. We also tested predictions about environmental boundary conditions. In harsher living conditions (e.g., higher homicide or pathogen rates), the effect of increased population density on fertility rates was attenuated. The density-fertility association was also moderated by religiousness and strength of social norms, where the relationship between density and fertility was attenuated in countries with high religiosity and strong social norms. We discuss why and when changes in population density may influence fertility rates and the broader implications of this work.
AB - Fertility rates have been declining worldwide over the past 50 years, part of a phenomenon known as “the demographic transition.” Prior work suggests that this decline is related to population density. In the present study, we draw on life history theory to examine the relationship between population density and fertility across 174 countries over 69 years (1950 to 2019). We find a robust association between density and fertility over time, both within and between-countries. That is, increases in population density are associated with declines in fertility rates, controlling for a variety of socioeconomic, socioecological, geographic, population-based, and female empowerment variables. We also tested predictions about environmental boundary conditions. In harsher living conditions (e.g., higher homicide or pathogen rates), the effect of increased population density on fertility rates was attenuated. The density-fertility association was also moderated by religiousness and strength of social norms, where the relationship between density and fertility was attenuated in countries with high religiosity and strong social norms. We discuss why and when changes in population density may influence fertility rates and the broader implications of this work.
KW - Crosscultural differences
KW - Demographic transition
KW - Fertility
KW - Life history theory
KW - Population density
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U2 - 10.1037/amp0000862
DO - 10.1037/amp0000862
M3 - Article
C2 - 34914431
AN - SCOPUS:85122845699
SN - 0003-066X
VL - 76
SP - 933
EP - 946
JO - American Psychologist
JF - American Psychologist
IS - 6
ER -