Abhatoo - Centre Nationale de Documentation

Modern industrialised populations lack the strong positive correlations between wealth and fertility that characterise most traditional societies. While modernisation has brought about substantial increases in personal wealth, fertility in many developed countries has plummeted to the lowest levels in recorded human history. These phenomena contradict evolutionary and economic models of the family that assume increasing wealth reduces resource competition between offspring, favouring high fertility norms. Here, we review the hypothesis that cultural modernisation may in fact establish unusually intense reproductive trade-offs in wealthy relative to impoverished strata, favouring low fertility. We test this premise with British longitudinal data (the Avon Longitudinal Study of Parents and Children), exploring maternal self-perceptions of economic hardship in relation to increasing family size and actual socio-economic status. Low income and education mothers perceived the greatest reproductive costs associated with raising one versus two offspring. However, for all further increases to family size, reproduction appears most expensive for relatively wealthy and welleducated mothers. We discuss our results and review current literature on the longterm consequences of resource dilution in modern families.