Document Detail

Sex ratio at birth, polygyny, and fertility: a cross-national study.
MedLine Citation:
PMID:  17019835     Owner:  NLM     Status:  MEDLINE    
The sex ratio at birth may reflect frequency of intercourse that affects the timing of conception. If so, cross-national variation in polygyny and fertility might account for country differences in secondary sex ratios. Consistent with the timing of intercourse hypothesis, the birth sex ratios of 148 countries declined with total fertility rates and polygyny intensity, and increased with contraception use in correlational analysis. Regression analysis confirmed that polygyny was a negative predictor of the sex ratio (and contraception was a positive predictor), with level of economic development and mother's age controlled, but the effects disappeared with total fertility added to the equation. The sex ratio evidently declines with increases in fertility because more children are born at a later birth order when frequency of intercourse is lower.
Nigel Barber
Related Documents :
19000295 - From birth to adulthood in rural ethiopia: the butajira birth cohort of 1987.
1585135 - Socio-economic factors and feto-infant mortality.
8500635 - Writing the names: marriage style, living arrangements, and first birth interval in a n...
14717305 - Births: final data for 2002.
1417215 - Placental plasmodium falciparum parasitaemia in east sepik (papua new guinea) women of ...
8606015 - Neonatal sucking and maternal feeding practices.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Social biology     Volume:  51     ISSN:  0037-766X     ISO Abbreviation:  Soc Biol     Publication Date:    2004 Spring-Summer
Date Detail:
Created Date:  2006-10-05     Completed Date:  2006-11-06     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0205621     Medline TA:  Soc Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  71-7     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Birth Order
Contraception / utilization*
Cross-Cultural Comparison
Interviews as Topic
Marriage / ethnology,  statistics & numerical data*
Maternal Age
Parturition / ethnology*
Sex Factors
Sex Ratio*
Time Factors

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Required parental investment and mating patterns: a quantitative analysis in the context of evolutio...
Next Document:  Initial management of hypertension in a primary care service