Scientists reveal how men evolved to masturbate – but admit they don’t know why it started in women
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How humans evolved to masturbate: Scientists say self-stimulation helped men avoid STDs — but admit they have no idea why it started in women
- Previous studies suggest that masturbation is a by-product of sexual arousal
- But a new study suggests it actually served an evolutionary purpose in men
- It evolved in male primates to increase mating success and help prevent STIs
It is often seen as a taboo, despite it being something many people do.
But scientists have cast aside any embarrassment about masturbation in a new study of the practice’s origins.
While previous studies suggested that masturbation was simply a by-product of sexual arousal, the UCL team argues that the behavior actually served an evolutionary purpose — at least in men.
Their findings indicate that masturbation evolved in male primates to increase mating success and help prevent STIs.
However, the scientists admit that when it comes to women, they are still clueless about the origins of masturbation.
It is often seen as a taboo, despite it being something many people do. But scientists have brushed aside any shame about masturbation in a new study of the practice’s origins (stock image)
Masturbation is not only practiced by humans – it is common in the animal kingdom, especially among primates.
However, until now it has remained unclear how and when it became widespread.
In the new study, the team collected the largest-ever dataset of primate masturbation, including information from nearly 400 sources.
Their analysis of the data revealed that masturbation dates back millions of years and was probably even practiced by the common ancestor of apes and humans.
To understand why evolution would favor masturbation, the team tested several theories.
The ‘postcopulatory selection hypothesis’ suggests that self-stimulation improves fertilization in several ways.
First, masturbating (without ejaculation) before sex increases arousal — a tactic that may be especially helpful for low-ranking men who are likely to be interrupted during sex, by helping them ejaculate more quickly, the researchers said.
Second, masturbation (with ejaculation) causes males to shed inferior sperm, leaving fresh, high-quality sperm available for mating.
The next hypothesis, called the “pathogen avoidance hypothesis,” states that masturbation reduces the risk of an STI after sex by cleaning the urethra.
The team found evidence to support both hypotheses.
Dr. Matilda Brindle, lead author of the study, said: ‘Our findings help shed light on a common but little understood sexual behavior and represent a significant advance in our understanding of the functions of masturbation.
“The fact that autosexual behaviors can have an adaptive function, are ubiquitous throughout the primate order, and are practiced by captive and wild members of both sexes, demonstrates that masturbation is part of a repertoire of healthy sexual behaviors.” .’
The team admits it still doesn’t know how or why female masturbation evolved, but now hopes to analyze further data to understand its role.
The study comes shortly after researchers at the University of Lethbridge revealed how macaque monkeys — both male and female — often use stone tools as sex toys to pleasure themselves.
The team studied video footage of long-tailed macaques in the Sacred Monkey Forest Sanctuary from 2016-2019.
In the videos, they saw hundreds of examples of monkeys rubbing or tapping their genitals with rocks while sitting.
The males played with the stones more when their penises were outstretched with one hand or erect, suggesting the action was for sexual pleasure, the researchers said.
However, it was more difficult to understand whether the females rubbed the stones for sexual pleasure or not.
They tended to choose rougher stones to apply to their genitals, which the researchers say may provide more stimulation than smooth stones.