Will a child survive? Older siblings have a powerful influence

"Swiss birth data from 1750 to 1870 reveal that girls who had lots of older brothers close to their own age were less likely to survive than were those who did not. Having older siblings affects a child's chance of survival - but the precise effect depends on the older siblings' sex and age. Access options Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription"

"Having older siblings affects a child's chance of survival - but the precise effect depends on the older siblings' sex and age. Access options Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription Subscribe to this journal Receive 51 print issues and online access $199.00 per year only $3.90 per issue Prices may be subject to local taxes which are calculated during checkout"

Swiss birth records from 1750 to 1870 show that sibling composition influenced child survival. Girls who had many older brothers close in age exhibited lower survival probabilities than girls without such brothers. The presence of older siblings altered survival odds for children overall. The directional effect varied depending on the older siblings’ sex and their age relative to the focal child. The data imply family composition and competition among close-in-age siblings contributed to mortality patterns in historical Switzerland. The findings indicate nuanced interactions between sibling sex, sibling age spacing, and child survival outcomes.

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