Male monkeys have more sex with males than females – and that’s an advantage

Same-sex sex is not only common in humans, it is also more common in the animal world. In rhesus macaques, males are even more likely to have sexual relations with other males than with females. A group of scientists observed such a population in Puerto Rico for three years, and the researchers have now presented their results in the journal “Nature Ecology & Evolution.”

According to this report, 72 percent of men have sex with other men and only 46 percent have sex with the opposite sex. There are several theories as to why this is: lack of women, dominance behavior or just sexual desire. Now the researchers, in collaboration with biologist Vincent Savolainen, have come up with a new theory based on their observations.

The men who had sex with other men were also more likely to support each other in fights. In addition, these monkeys also had sex with females more often – and therefore more offspring than the purely heterosexual monkeys. According to Savolainen, this could even be related:

The offspring of these relationships also have more same-sex sex, more support, and in turn, more offspring. That is why the researchers speak of an evolutionary advantage. However, this finding should make you sit up and take notice.

Using genetic testing and detailed pedigrees, the researchers found that 6.4 percent of these behaviors are hereditary. It is difficult to attribute behavior to specific genes. That is why this percentage – albeit low – is around the average. Studies of such a connection have produced similar results, for example for personal hygiene or other social behavior.

However, the researchers note that the sexuality of monkeys differs from that of humans. Still, these results showed variability by gender: