Gene Expression

Foreskin doesn’t add “value”?

Circumcision doesn’t reduce sensation: study:

The study, published in The Journal of Sexual Medicine, looked at a group of 40 men, half of them circumcised. Using sensory testing, the men were monitored at two points on the penis and the forearm while viewing erotic films. Thermal imaging was used to measure sexual arousal.

I think one can criticize this study on the relative coarseness of measure, after all, registering qualia is not a trivial task. Nevertheless, do note that in my previous comment on circumcision I did suggest that “pleasure” might be renormalized by the brain. Remember how good McDonald’s tasted when you are 8 years old?

Related: Circumcision & AIDS, Circumcision – human rights issue?, and Circumcision – HIV vs. pleasure?.


  1. #1 Brian
    July 30, 2007

    Did they even test the foreskin relative to other parts of the penis? I’ll believe that the glans and shaft skin has the same or similar sensitivity, circumcised or not, but how does the foreskin compare to the rest of the penis?That’s the missing part in circumcised dudes, so the only valuable comparison is the foreskin to the rest of the penis.

  2. #2 ZetJi
    July 30, 2007

    yeah, I wouldn’t be at all surprised if the brain picks up the slack and recalibrates the areas that corresponded to the foreskin to instead enhance the pleasure from the remaining sexual tissue. IIRC the brain is very capable, especially at an early age, of retooling brain regions if their normal sensory input stops being received.

    The brain might not have the plasticity for this retooling in adults however, which is a point against the whole “let them wait until their old enough to decide” argument.

  3. #3 colpen
    July 30, 2007

    Razib, why did you not mention that this study by Kimberley Payne failed, as the first poster Brian noted, to measure sensitivity in the foreskin?

    This is a science blog! Where is your scientific though process?

    If one is deliberately doing a sensitivity comparison between circumcised and intact men, what kind of foolishness is required to ignore the unique anatomical structures which are missing in one group due to their surgery?

    When you don’t ignore the foreskin, you get the real results:

    Razib, were you aware of this study? If not, why didn’t you do some research? If so, why didn’t you mention it?

  4. #4 razib
    July 30, 2007

    Razib, were you aware of this study? If not, why didn’t you do some research? If so, why didn’t you mention it?

    hey dude, seriously, put your links in the comments. but don’t fucking dictate to me how to post OK??? SOMETIMES I DON’T HAVE AS MUCH FUCKING TIME AS YOU, NOR AM I AS INTERESTED IN A TOPIC AS YOU, YOU FUCKING UNDERSTAND???? if i were you, i would just post my links and arguments. if you keep up the mother-fucking attitude i’m going to delete all your comments, you understand? OR SHOULD I FUCKING REPEAT IT ALL CAPS???

  5. #5 colpen
    July 30, 2007


  6. #6 razib
    July 30, 2007

    word of advice on getting people to agree with you: don’t berate them. i was open too, and expecting your critiques. would you rather have me post nothing instead of viewing this as a teachable moment?

  7. #7 colpen
    July 30, 2007


    I recalled circumcision having been discussed before at scienceblogs, and that you were part of the discussion. I made the assumption that you were aware of the issues regarding these sensitivity studies. If that was not the case, and this is new territory for you on which your mind is open, then my approach was not the right one, and I my comment was unnecessarily incisive.

    I hope we can start over, and that this blog can serve as a science-oriented, honest discussion of the issue.

  8. #8 Adam
    July 30, 2007

    Perhaps swearing, all-caps, and threats aren’t an ideal way to maintain readership.

  9. #9 razib
    July 30, 2007

    Perhaps swearing, all-caps, and threats aren’t an ideal way to maintain readership.

    i don’t give a fuck about the quantity of readership. i’ve made that pretty clear before.

    colpen, i’m not going to keep track of this thread because i’m busy right now. that explains why i didn’t explore the issue in greater detail. myself, i tend to be personally ‘anti-circumcision,’ and i put these posts up in hopes of furthering a discussion and airing out the different vantage points. scienceblogs has been picked up on google news and i always get a large number of circ related hits. put post up so that people could have a chance to give feedback since it will no doubt be picked up by the media.

  10. #10 Caledonian
    July 30, 2007

    I hope they tested different kinds of touch. IIRC, the type of nerve ending that the foreskin is particularly rich in responds to sliding friction – not pressure or mere tactile contact.

  11. #11 Keil
    July 30, 2007

    Caledonian, do you have a source for that info about foreskin nervous tissue composition? I think a cellular physiology viewpoint could be enlightening on this issue.

  12. #12 Caledonian
    July 30, 2007

    Alas, no. One of the drawbacks of having a large trivia store is that finding sources is usually impossible.

    I do recall reading it in multiple sources. You might consider checking the comments in the previous circumcision thread – someone might have discussed it there. Slogging through it all might be a bit much, though.

  13. #13 marsveblint
    July 31, 2007

    “…circumcision…unnecessarily incisive…”


    Blogs are the best place for swearing. Maybe not wrath. But definitely swearing. Especially the F-bomb.

    There are a lot of science people who love F-bombs. Me, I can’t imagine how we would get anything done in the lab without them. Coordinated efficiency, y’know. Takes a blue collar spirit. I think Khan’s kosher with scientific method here, talkin’ rage on an ad hoc basis. There are plenty of occasions I could cite where the lab supervisor properly issued reminders that ‘this is not a fucking democracy.’

    Historically speaking, there have been few ameliorations more effective against Hephaestian rage than those provided by Aphrodite. Should the gentlemen of the thread be receptive, I might suggest considering the feminine component of fucking’s “value” as it relates to circumcision.

    I actually know some people who define fucking’s value as “a product of male-female synergy.” A controversial notion? Sure. But as I understand, whenever the fairer sex is polled, the majority generally prefers a cut cock. Easier to rake the button than to have to pinpoint it every time, I would imagine. Nonetheless there are studies that would suggest the woman’s opinion matters to science:

    Speaking of college ladies, I am reminded of a splendid joke I was once told while fucking around with methylbenzoic acid ester syntheses in a lab sponsored by a midwestern university:

    Pledge: How long does it take for a woman to have an orgasm?
    Turn: I don’t know, how long?
    Prestige: Who cares!

    Now that’s good humor. But if we want objectivity, it might be worth investigating the value of feedback when it comes to overall “value.” A study on the relationship between fecundity and orgasmic capacity in women might illuminate some new angles when it comes to defining and implementing sound motherfucking policy, circumcision issues inclusive.

    The other angles on this topic, such as from the human rights and epidemiological positions, seem to have been beaten about for years, and will be unsurprisingly flaccid instruments for the purposes of increasing quantity readership.

    But unless we are talking about those issues, the remaining discussion can’t be much but subjective. Renormalization, sure. For men, that process tends to recur within the friendly grip of every new vagina, simulated or real.

    Attention: Of course fucking sensation is lost. The issue is whether there is a tradeoff, and as it stands there doesn’t appear to be any studies indicating properly-circumcised men have a significant outstanding impediment when endeavoring to ejaculate inside a warm vagina, much less on a soft thigh or belly, on the ass or back, shoulders, sleek calves, hands or feet with painted toenails, or anywhere on or about the face or hair. Nor does any evidence seem to exist that any confirmed achievement of such ends should be surmised as somehow less sweet for the cut as the uncut.

  14. #14 Sandgroper
    July 31, 2007

    But the bold type, caps and f-bombs are the most fun part. It’s the Razza we know and love – I wouldn’t change a thing, me. And he does leave scope for discussion and introduction of additional points instead of trying to supply all the answers. Why should he supply all the answers? Last time I checked, I’m not actually paying Raz to supply all this information.

    Forearm??? WTF? Have I been missing an important erogenous zone all these years? Damn.

  15. #15 Caledonian
    July 31, 2007

    It occurred to me last night that the number of women who received clitoral reductions as children and had difficulty reaching orgasm as adults suggests that the brain can’t remap itself to a reduced genital stimulus space.

    Women are wired very differently than men, though, but given that men don’t need any genital stimulation at all to orgasm, clearly demonstrating that any partial removal is harmful is difficult at best.

  16. #16 Scott
    July 2, 2009

    I’ve read several debates online in regards to the foreskin, but I have yet to have read a scientific analysis of why (through natural selection) the foreskin exists. One post, on another site, suggested that the foreskin predates man as many other mammals have it.

    What if we apply the 50/50 test wherein we take 100 cavemen, apply any human trait to 50 of them and then examine if they would be aided by the trait – and then outproduce (outbreed) their 50 competitors? What advantage does the foreskin produce?

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