title: The impact of sex ratio and economic status on local birth rates.
abstract: Human mating and reproductive behaviour can vary depending on various mechanisms, including the local sex ratio. Previous research shows that as sex ratios become female-biased, women from economically deprived areas are less likely to delay reproductive opportunities to wait for a high-investing mate but instead begin their reproductive careers sooner. Here, we show that the local sex ratio also has an impact on female fertility schedules. At young ages, a female-biased ratio is associated with higher birth rates in the poorest areas, whereas the opposite is true for the richest areas. At older ages, a female-biased ratio is associated with higher birth rates in the richest, but not the poorest areas. These patterns suggest that female-female competition encourages poorer women to adopt a fast life-history strategy and give birth early, and richer women to adopt a slow life-history strategy and delay reproduction.
authors: Centre for Comparative and Evolutionary Psychology, University of Portsmouth, Portsmouth, UK. abby.chipman@port.ac.uk
authors: A
authors: A
authors: Chipman
authors: E
authors: E
authors: Morrison
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001723:Birth Rate; D003163:Competitive Behavior; D003710:Demography; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D011610:Psychosocial Deprivation; D043762:Reproductive Behavior / Q000523:psychology*; D012744:Sex Ratio; D063507:Sexism; D012923:Social Class; D013997:Time Factors; D055815:Young Adult