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An evolutionary case for polygyny to counter demographic collapse
1Centre for Development and the Environment, University of Oslo, Oslo, Norway.
Frontiers in Psychology
|February 23, 2023
Summary
Modern gender-equal societies may be experiencing declining fertility due to perceived sex ratios. Exploring evolutionary mating practices suggests openness to polygyny could boost reproduction rates and avert demographic collapse.
Area of Science:
- Evolutionary psychology
- Demography
- Sociology
Background:
- Global fertility rates are declining, with over 20 nations projected to halve populations by 2100, leading to societal instability.
- Nordic countries, leaders in gender equality, exhibit high rates of single-person households and declining fertility, suggesting a link between perceived sex ratios and reproduction.
- Evolutionary history shows mating practices (promiscuous, polygynous, monogamous) shaped human mate preferences, influencing cultural and behavioral responses to environmental shifts.
Purpose of the Study:
- To investigate how perceived sex ratios in modern, gender-equal societies contribute to low reproduction and singlehood.
- To explore the evolutionary basis of human mating practices and their influence on contemporary reproductive norms.
- To propose that reconsidering openness to polygyny might be a strategy to increase fertility rates in developed nations.
Main Methods:
- Analysis of demographic statistics from Nordic countries, focusing on fertility rates and household structures.
- Review of sex ratio theory and its implications for mating behaviors in contemporary societies.
- Evolutionary analysis of hominin mating systems from ancestral primates to modern humans, incorporating insights from literature.
Main Results:
- Perceived scarcity of acceptable partners in gender-equal environments correlates with increased singlehood and reduced fertility.
- Women's perception of a skewed sex ratio may activate a polygynous mindset, leading to promiscuity over pair-bonding in monogamous societies.
- Historical mating practices and the imposition of monogamy have shaped modern reproductive norms, which may now be counterproductive to population growth.
Conclusions:
- Modern societal structures and perceived sex ratios significantly impact reproductive behaviors, challenging traditional models.
- The historical success of monogamy in shaping modernity may be insufficient to drive reproduction in current gender-equal contexts.
- An evolutionary perspective suggests that adapting mating system considerations, potentially including polygyny, could be necessary to address demographic decline.
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