Around 40 million years before the first humans set foot on the planet, masturbation—historically thought to be pathological or a by-product of sexual arousal—was first observed in extinct monkeys.
The majority of males had this characteristic, which led scientists to speculate that the apes used self-pleasure strategies to increase their reproductive potential and, in turn, protect themselves from acquiring STDs.
The findings were published after collating data from 400 sources, including 246 published academic papers
After compiling data from roughly 400 sources, including 246 published academic publications, 150 questionnaires, and personal letters from primatologists and zookeepers, the findings were published in Proceedings of The Royal Society B journal.
To determine when and why autosexual behavior arose in both males and females, scientists studied the distribution of this behavior among primates.
“Our findings help shed light on a very common, but little understood, sexual behavior and represent a significant advance in our understanding of the functions of masturbation,” Dr. Matilda Brindle, the lead author of the study, said in a statement.
However, there is a scientific explanation for why primates regularly masturbated.
According to their theory, male masturbation increased the likelihood of getting pregnant and helped men get rid of their old sperm, giving them newer, more competitive sperm for intercourse.
Masturbating following intercourse aids in genital tract flushing: Experts
That was not the only factor, though. According to the study, the prevalence of sexually transmitted illnesses increased along with male masturbation in primates.
The experts speculate that masturbating following intercourse aids in genital tract flushing, lowering the likelihood of an infection taking hold.
Despite the study’s detailed exploration of male libido’s functioning, it largely ignores female masturbation.
The researchers had much less information and data to draw upon because biological investigations in the past tended to exclude females.
“More data on female sexual behavior is needed to better understand the evolutionary role of masturbation,” she said.
Explaining why she decided to focus her research on this topic, Brindle said she found it “absolutely baffling that nobody has researched such a common behavior across the animal kingdom”.
“For people who think masturbation is wrong, or unnatural in some way, this is a perfectly natural behavior. It’s part of our healthy repertoire of sexual behaviors,” she added.