Sixty-two Canadian men had their genitals poked and prodded to determine if foreskin matters for sexual pleasure.
It's an age-old debate, and the resulting paper from Queen's University in Ontario, Canada, seeks to settle it. The paper finds evidence that circumcised men don't have any less sensitivity in their penises than men with intact foreskins.
"There’s a lot of popular folklore that circumcised penises are less sensitive," Jennifer Bossio, a PhD student in psychology who was the lead author on the study, published in The Journal of Urology, tells me. Without a foreskin, the lore goes, the glans (head) of a man's penis becomes keratinized — or hardened slightly, like the craggy calluses on the backs of feet. These rougher penises, then, are thought to have less feeling.
"This study points to the fact that it might not be the case," Bossio says. To find out, Bossio gathered 62 men (about half were circumcised, half were intact) in the Ontario area to have their penises prodded by various tools to assess sensitivity to touch, pain, and heat.
"Come on in, we're going to poke you and burn you!" Bossio says in jest about their pitch to participants. The real sell: The brave men got 75 Canadian dollars (about $59 in US dollars) for their time. (For the record, Bossio admits that people who sign up for sexuality studies may not be perfectly representative of the population. A few people, she mentions, joined "for beer money.")
Bossio and her colleagues tested responses to pain, touch, and heat on four areas of the participants' genitals. This is where they put the instruments. This might not be safe for (your) work. As a science reporter, it is safe for mine.
At each of these contact points, the researchers slowly upped the intensity of each test until the participant said he felt something. With this data, Bossio and her colleagues could calculate an average sensitivity threshold for each group and then compare.
The results: Bossio and her team couldn't detect a difference.
"The keratinization hypothesis was not supported by this study," the paper states. It concludes: "Circumcision is not associated with changes in penile sensitivity," and the foreskin "is not the most sensitive part of the penis."
Bossio stresses this is just a preliminary study on a topic that has seen very little research.
There has been a lot of research into whether circumcision is good for health. (The Centers for Disease Control and Prevention acknowledges circumcision has some medical benefits, like decreasing the likelihood of transmitting HIV.) "But there’s almost nothing on the effect on the sexual lives of men," she says. "A third of men in the world have been circumcised — so we’re talking about a huge proportion of men — and we have no idea of the impact on their sexual lives. To me, that’s an important question."
The study is also limited by a small sample size. Research papers ideally have 200 participants, not 60. But that no effect was found in this small group probably means if a difference does exists, it's likely very small.
Even if there's a tiny difference, it's unlikely to matter in practice. In other, yet-to-be published work, Bossio says she finds that circumcision status does not make a difference for sexual arousal (which she studies via blood flow tracking in the genital region as participants watch porn). And in the current study, she finds that all men report similar sexual satisfaction overall.
But what about the foreskin? Doesn't having it intact add some pleasurable experience?
Bossio did assess the sensitivity of the foreskin itself, and found that while it is very sensitive to a light touch, it's not very sensitive to pain or warmth, which "are actually more relevant to the experience of sexual touch or sexual enjoyment," she says. Removing the foreskin, she then concludes, "is probably not going to have that big of an impact on people’s sexual experience."