Playing With Yourself Has Been Perfected Over Millions of Years: Report

A new study out of the U.K. suggests that masturbation evolved in primates tens of millions of years ago, and it not only increases the chances of having children, but the behavior may also have evolved to help decrease the chances of acquiring sexually transmitted infections.

The research by University College London, which examined masturbation in male primates, found that self-pleasuring could help up the possibility of successful fertilization due to the male becoming more aroused before sex, Sky News reports.

Researchers also discovered that ejaculating after masturbation can help get rid of low-quality semen, which leaves fresh semen for fertilization.

"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," Matilda Brindle, the lead researcher, told the outlet.

Brindle told the Guardian, “What we can say is this behavior was present around 40m years ago, in the common ancestor of all monkeys and apes.”

She added, “It’s not that some species woke up one day and started doing it. This is an ancient, evolved trait.”

The Guardian describes the behavior as an “evolutionary conundrum.” Speaking in evolutionary terms, masturbation is essentially wasteful.

Fresh sperm doesn’t seem to be the only driver for primates to masturbate. Researchers also found that masturbation rose along with STIs, and wrote that it could help flush the genital tract and thus decrease infections.

While masturbation is common in the animal kingdom, primates — like chimpanzees, bonobos, and humans — do it more often.

The scientists said that female masturbation is still not well-understood from an evolutionary perspective. One thought, according to the research team, is that female masturbation could allow female primates some control over fertilization.

The study was published in the journal Proceedings of The Royal Society B.

It looked into wild and captive primates, gathering information and data from almost 250 academic papers and 150 questionnaires related to the subject.

“For people who think masturbation is wrong, or unnatural in some way, this is perfectly natural behavior. It’s part of our healthy repertoire of sexual behaviors,” Brindle said.

“This is such a common behavior across the animal kingdom, I find it absolutely baffling that nobody has researched it before.”