Reproductive status of mothers affects sex-biased parental investment in humans.
An analysis of the sexual differences in birth weights of 381 children showed that boys are heavier than girls for multiparous mothers but not for primiparous ones. The results support the current hypotheses that predict sex biases in parental investment, with higher costs of producing male offspring in some mammals.
San Jose
C
C
Estación Biológica Doñana (CSIC), Sevilla, Spain.
Braza
F
F
Casanova
X
X
D001724:Birth Weight; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009679:Nuclear Family; D010298:Parity; D011287:Prejudice; D012727:Sex Characteristics; D012737:Sex Factors