Male chimps prefer older women who’ve been around, study finds
A study in Uganda found that older females were more likely to be approached for sex, to associate with males during their fertile periods, and to mate with the most desirable high-ranking males.
Older females were also the cause of more conflict between rival males than younger females.
The male chimps’ behaviour contrasted sharply with that typically seen in men, who tend to be attracted to youth and beauty, said the US scientists, led by Dr Martin Muller, from Boston University in Massachusetts.
They wrote in the journal Proceedings of the National Academy of Sciences: “Multiple lines of evidence indicate that, unlike humans, female chimpanzees become more sexually attractive with age.”
The researchers observed a group of wild chimpanzees living in Kibale National Park in Uganda.
Unlike humans, female chimps do not experience a menopause so their fertility is not limited by age.
Chimpanzees are also far more promiscuous than humans, who tend to form long partnerships. These two factors could account for the fact that male chimps are not as ageist as male humans.
“Long-term pair bonds are hypothesised to promote preferences for youth because men who choose relatively young partners maximise their future reproductive opportunities with those partners,” the scientists wrote.
Male chimps may prefer older mates because long experience of mothering led to increased infant survival, the scientists found. Females of an advanced age also tended to be of higher genetic quality.
“We conclude that natural selection has shaped male biases for specific cues of female mate value very differently in chimpanzees than humans,” said the scientists.
