Abstract
There is considerable debate as to whether human females bias the sex ratio of their offspring as a function of their own condition. We apply the Trivers–Willard prediction—that mothers in poor condition will overproduce daughters—to a novel measure of condition, namely wife rank within a polygynous marriage. Using a large-scale sample of over 95 000 Rwandan mothers, we show that lower-ranking polygynous wives do indeed have significantly more daughters than higher-ranking polygynous wives and monogamously married women. This effect remains when controlling for potential confounds such as maternal age. We discuss these results in reference to previous work on sex-ratio adjustment in humans.
Original language | English |
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Pages (from-to) | 765-768 |
Journal | Biology Letters |
Volume | 5 |
Issue number | 6 |
Early online date | 8 Jul 2009 |
DOIs | |
Publication status | Published - 23 Dec 2009 |
Externally published | Yes |