Jennifer Bossio confirmed: foreskin most sensitive part of penis

Yet she was too biased to admit it!

Bossio, Jennifer, “EXAMINING SEXUAL CORRELATES OF NEONATAL CIRCUMCISION IN ADULT MEN” is a PhD thesis which attempts to “provide a multidimensional perspective of the sexual correlates of circumcision with implications for public policy and individual stakeholders (e.g., medical professionals, parents, men).”

Jennifer Bossio validated Sorrells study and didn't recognize it

Jennifer Bossio validated Sorrells study and didn’t recognize it.

Chapter 3 is dedicated to study penile sensitivity in men who were circumcised as babies, vs. men who were not circumcised (intact). This is evidently a response to the 2007 study “Fine-touch pressure thresholds in the adult penis” by Sorrells et al.

Bossio writes (pg. 69): “we did not obtain sufficient evidence to support the notion that the foreskin of adult intact men is the most sensitive region of the penis to all forms of stimuli; however, the foreskin was significantly more sensitive to touch as compared to all the other genital sites tested, and it was significantly more sensitive to warmth than the glans penis.” She also writes: “our results—and those of Payne et al. (2007)—differ from those of Sorrells and colleagues (2007) who found that the glans penis in circumcised men was less sensitive to touch than in intact men.”

In her conclusions, Bossio writes that “we directly assessed the assumption that circumcision leads to a reduction in penile sensitivity by testing tactile detection, thermal sensation, and pain thresholds at multiple sites on the penis” and offers one conclusion that “this study provides no evidence that neonatal circumcision decreases penile sensitivity, no evidence that the exposed glans penis in circumcised men becomes less sensitive over time, and insufficient evidence to suggest that the foreskin is the most sensitive part of the penis.” and then suggests that “if differences in sexual functioning or sexual dysfunction are related to circumcision status, these differences are not likely the result of changes in penile sensitivity resulting from neonatal circumcision

Finally, she concludes that “findings from this study can be used to inform individual stakeholders, public policy makers, medical health care professionals, and parents regarding the minimal long-term implications of neonatal circumcision on penile sensitivity.”

We have issues with the inclusion and exclusion criteria. Excluding participants over 40 years of age creates a bias. Many individuals restoring their foreskins typically started after their 40s. They also excluded individuals with history of sexual dysfunction.

Reading her paper we found contradictions to her assertions that “this study provides no evidence that neonatal circumcision decreases penile sensitivity [...] and insufficient evidence to suggest that the foreskin is the most sensitive part of the penis“.

We also suggest that Bossio missed a vital point by neglecting to study men who have undergone non-surgical foreskin restoration.

First, the assertion that the foreskin is the most sensitive part of the penis comes directly from the Sorrells study, and it is one assertion that is often misunderstood. Sorrells simply evaluated “fine-touch pressure thresholds” – nothing more, nothing less. So when Sorrells concluded that “circumcision ablates the most sensitive parts of the penis” it should be read that “circumcision ablates the most sensitive parts of the penis [to fine-touch]“. Sorrells did not make any attempt to measure pleasure or satisfaction. Only fine touch, and his findings are consistent with those of Bossio as she said it herself, that “the foreskin was significantly more sensitive to touch as compared to all the other genital sites tested“.

So, if the foreskin is significantly more sensitive to touch, it follows that the circumcised penis, in which the foreskin has been removed, is less sensitive to touch – particularly to fine touch. Which again, contradicts her conclusion that her study “provides no evidence that neonatal circumcision decreases penile sensitivity“.

Now, we partially agree with her assertion that “if differences in sexual functioning or sexual dysfunction are related to circumcision status, these differences are not likely the result of changes in penile sensitivity resulting from neonatal circumcision“, basically because the studies are missing one important point. Static stimulation is not the main method of stimulation during sexual activity. People don’t just lie down being stimulated by touch, warmth, pain, etc. Individuals move during sex. Stimulation is dynamic.

A visual comparison between a typical intact man masturbating, and a circumcised man masturbating, yields important differences – and  this has even been observed by circumcision promoters such as Guy Cox – in a paper published with the pen name of James Badger. While Badger describes it as a difference in preference, the reality is that it is a difference in what is possible to do with the available tissue.

Most intact men masturbate by grasping the mobile penile skin and sliding it up and down the shaft. In most cases this results in the glans being repeatedly covered and uncovered, with the rim of the foreskin stimulating the glans; typically the hand does not touch the glans. In the case of males with particularly long foreskins, the glans may never be uncovered at all, and the hand stimulates the glans only indirectly, through the foreskin.

In circumcised males, the typical technique consists in moving the penile skin what little length it can be moved during erection, or when no mobile skin is available at all, the hand rubs the penile skin, in which case external lubrication (hand lotion or adult lubricant) is needed to avoid chaffing the skin. In many cases direct contact with the glans is avoided unless using lubricant.

What this indicates is that there is a mechanic component of stimulation by using the foreskin as an agent, a mobile part, which interacts with the glans. Obviously, removing the foreskin makes this action impossible, thus altering the mechanism of stimulation for the circumcised male.

We can also consider that during heterosexual penetration, the glans touches the opening of the vagina and goes through its vestibule, but once inside it is not in contact with anything else. The vagina instead is grasping the penile skin, and facilitating its gliding motion during the repeated penetrative motion. For the circumcised male, the vagina simply rubs directly against the penile skin – because there is no movement of the skin, which tends to dry the lubrication of the vagina.

So there is a change that goes deeper than simple passive sensitivity. Circumcision alters the mechanics of the penis and causes stimulation to be different, both for the male and the female.

Bossio’s paper simply moves between two contradictory positions: 1) that the foreskin is more sensitive to touch, and 2) that the circumcised penis is as sensitive as the intact penis – which is simply not possible if a) the foreskin is more sensitive to touch and b) has been removed by circumcision.

It seems to me that given the importance of Sorrells’ study as a starting point to Bossio, she missed the mark. Neither Bossio nor her reviewers understood the meaning of “sensitivity” as used by Sorrells.

Perhaps the real importance of Bossio’s paper was to superficially contradict Sorrells, as an attempt to undermine a common argument used by promoters of genital integrity, and by calling the long-term implications of neonatal circumcision on penile sensitivity “minimal” she gained enough approval from a culturally biased academic community to obtain her PhD.

Misuse of Bossio’s paper:

Annette Fenner published in Nature Reviews Urology a highlight of Bossio’s published study (on The Journal of Urology), which is related to her thesis, with the superficial headline “Circumcision does not affect sensitivity“, and the first sentence, predictably enough, reads “Neonatal circumcision has minimal effects on penile sensitivity“. Fenner misrepresents Bossio’s paper by indicating that “No differences in tactile or pain thresholds, or sensitivity to warmth and heat pain, were observed between circumcised and intact men“. This clearly contradicts Bossio’s assertion that “the foreskin was significantly more sensitive to touch as compared to all the other genital sites tested“.

She then offers an allegedly quoted conclusion that Bossio’s data “do not support the idea that foreskin removal is detrimental to penile sensitivity.” – a quote that is really an inaccurate paraphrase, and we repeat, is deeply flawed based on the non-existent definition of sensitivity.

Fenner then offers her own conclusion, the one that everybody was hoping for, the direct contradiction to Sorrells: “removing the foreskin does not, in fact, remove the most sensitive part of the penis.”

We have already shown above how deeply flawed is this, given that the same assertion is contradicted by Bossio herself.

But that’s what Bossio’s thesis was written for: to allow culturally biased academics to contradict Sorrells’ study by quoting a paper that didn’t understand what Sorrells was writing about, and which is so poor that it contradicts itself without raising the eyebrows of any mindless reviewer.

Misleading headlines

We wrote this review back in January, but we didn’t publish it, silently waiting. Last week, however, the media picked up Jennifer Bossio’s paper, and predictably, as we have often indicated, used misleading headlines to make this look as far more conclusive than it really is. Many of the articles we reviewed, clumsily include Bossio’s contradiction without pointing it out.

Some examples of these disappointing articles:

Science Daily: Neonatal circumcision does not reduce penile sensitivity in men, study finds (New research challenges widely accepted beliefs)

UPI: Study: Circumcision does not reduce penis sensitivity. This article even says “In men with foreskin, it was more sensitive to tactile stimulation than other parts of their penises, however when foreskin sensitivity was compared to other sites intact men had no greater sensitivity than the circumcised men” – the first part obviously contradicts the premise of the headline: if the foreskin is more sensitive to tactile stimulation, removing it has to reduce the penile sensitivity (to tactile stimulation). The second part of the statement simply makes no sense and seems to be a derailing tool.

Tech Times: Getting circumcised does not shrink male organ sensitivity.

Medical Express: Circumcision does not reduce penile sensitivity, research finds.  In this article, Bossio is quoted saying “We found that while the foreskin was more sensitive to fine touch, it was not more sensitive to the other stimuli we used, and those stimuli are likely more important in sexual pleasure“. However, that sentence alone already contradicts the headline – and the whole premise of Bossio’s publication. In fact, the underlined sentence alone shows that Bossio validated Sorrells’ study, the very study that she appears to be trying to contradict.

Queens University: NEWS RELEASE – New research finds circumcision does not reduce penile sensitivity. This must be the originating point of all these press releases, as Bossio’s study was the core of her PhD thesis at Queens University. This article, just like the one from Medical Express, quotes Bossio saying “We found that while the foreskin was more sensitive to fine touch, it was not more sensitive to the other stimuli we used, and those stimuli are likely more important in sexual pleasure” – which we are getting tired of repeating, contradicts the headline and the very premise of her study.

Daily Mail: Circumcision does NOT reduce sensitivity of the penis, experts say.  Unfortunately Bossio’s sad excuse of a study made its waves all the way to England. This article is preceded by 3 bullet points, one of which states: “Findings also suggest the foreskin is not the most sensitive part of the penis“. In this article, Bossio herself is quoted saying that her study “provides preliminary evidence to suggest that the foreskin is not the most sensitive part of the penis“. This version of the article avoids saying that “the foreskin was more sensitive to fine touch“, as the Queens University press release and the article on Medical Express did. Perhaps the contradiction would have been too obvious.

Healio, Medical Daily, True Viral News, Australian Networks, The Independent, I Fucking Love Science, GCO News, Renal and Urology News, Today’s Parent and many others also mindlessly reported on this absurd study.

So congratulations Jennifer Bossio. Your nonsense fooled a lot of people. Who knows how many men will be harmed because of your sad thesis.

UPDATE: Additional problems with Bossio’s paper

  • Some readers pointed out that Jennifer Bossio’s measuring point was the outside of the foreskin (see diagram). The foreskin is not a single structure. It has an outer layer of regular penile skin, and an inner layer of mucosa. There is also a transitional area which was pointed by Sorrells as the single most sensitive area to soft touch, and there is the frenulum, joining the ridged band and the inner foreskin to the glans and the meatus. Sorrells measured sensitivity at 8 different points of the foreskin. Bossio did not take measurements on the points indicated by Sorrells as the most sensitive ones to fine-touch sensation, which are the ridged band and the frenulum. Nevertheless, she found that the outer foreskin was significantly more sensitive to touch than the rest of the penis, which is consistent with Sorrells, even if her conclusions fail to indicate that.
    This was the site used by Bossio:
    These are the testing sites used by Sorrellssorrells_sites
  • According to the Queens University press release, Bossio “extended the research methods in her study to include warmth detection and heat pain because these stimuli are more likely to activate the nerve fibres associated with sexual pleasure“.For one, Sorrells did not make any claims regarding fine-touch sensitivity and pleasure.Second, “extending” the method makes the results difficult to compare. For example, Bossio writes “with respect to warmth detection, the foreskin was more sensitive than the glans penis, but not the midline shaft or an area proximal to the midline shaft. Using a different stimulus modality (warmth sensation, as opposed to fine-touch punctate pressure), we partially replicated the findings reported by Sorrells et al. (2007), in that the foreskin was more sensitive than the glans penis, but—unlike Sorrells—not two sites located on the penile shaft.” This makes no sense, because since Sorrells did not take measures of warmth sensitivity, there is no way to compare the data collected to Bossio in this aspect to anything in Sorrells study. It is not correct to say that this data “partially replicates” Sorrells given that they are referring to different types of stimulus.

    Sorrells declared that the foreskin was the most sensitive part (to soft-touch and to soft-touch only). Different parts of the body specialize in different kinds of sensitivity, according to our body’s needs. For example, our eyes are probably the most sensitive part to light. Our ears are probably the most sensitive part to sound. We wouldn’t try to assess sensitivity to sound in our eyes, or sensitivity to light in our ears. If the foreskin is sensitive to soft-touch, it is likely because we need that area to be sensitive to soft-touch, and removing it is going to affect the reasons why we need that sensitivity.

    Think about it this way. Removing one person’s eyes does not make the person deaf. But that is not a reason to justify removing the person’s eyes without necessity, particularly if we don’t know if the person needs to be sensitive to light.

  • Regardless of whether the foreskin is the most sensitive part, or just as sensitive as the rest of the penile skin, or if it was not sensitive at all, removing it would still violate the bodily autonomy and genital integrity of the person. Bossio writes on BJU that her “results are relevant to policy makers, parents of male children and the general public.” This statement misses the point that the most important stakeholder is the person holding the foreskin: the male child, the future male adult, and that no matter to what extent sensitivity is affected, removing the foreskin of the child deprives the child from the freedom to choose and the right to provide informed consent – thus violating his bodily autonomy and genital integrity.

    To be fair, on her thesis, Bossio writes that “Individual stakeholders are also expected to benefit from this research program, such as medical professionals, parents of male infants, and men themselves.” For some reason, “men themselves” were omitted from the conclusion in BJU.

  • Hugh Young pointed out that the graphics on Bossio’s thesis (i.e. figure 3.2) are collapsed across circumcision status. This conceals any existing difference between circumcised and uncircumcised.Figure 3.2 basically shows that the foreskin is more sensitive than the other testing points for tactile, warmth and heat pain (this last one only by a small difference), and that the glans is more sensitive to pain. The collapsed bars fail to show any difference. Young explains: “This makes the inclusion of the bar for the foreskin absurdly different from the others, because the foreskins of the cut men are non-existent. If their measurements were shown, their bars would be infinitely tall, indicating that no amount of pressure, heat etc, would evoke a response.” Sorrells study includes figures that are not collapsed by circumcision status. Two adjacent bars show the results for circumcised and uncircumcised. In the case of the circumcised males, the bar for non-existent measuring sites is simply omitted. If Jennifer Bossio wanted her study to be comparable to Sorrells, she should have considered presenting graphics that were comparable to those by Sorrells.Bossio’s figure 3.2

    Sorrells’ figure 3



Bossio, J.A.EXAMINING SEXUAL CORRELATES OF NEONATAL CIRCUMCISION IN ADULT MEN. Thesis (Ph.D, Psychology) — Queen’s University, 2015-09-18 00:15:45.183


Bossio, J.A. et al. Examining penile sensitivity in neonatally circumcised and intact men using quantitative sensory testing. J. Urol. (2015)


Sorrells ML, Snyder JL, Reiss MD, et al. Fine-touch pressure thresholds in the adult penis. BJU Int 2007;99:864-9.

Badger J. A Survey about Masturbation and Circumcision. 2000


Fenner, Annette  - Male circumcision: Circumcision does not affect sensitivity – Nat Rev Urol

PY  - 2016/01/20/online

VL  - advance online publication

18 thoughts on “Jennifer Bossio confirmed: foreskin most sensitive part of penis

  1. What is absolutely astonishing is that the dozens of media and scientific sites reporting this didn’t expose this obvious contradiction. Their headlines will make people think circumcision isn’t damaging , when, in fact, the research cited proves it is.

    But, of course, all those in the know knew this already as we have known about the histology of the penis for years. Circumcision is stripping the penis of the primary erogenous organ, rendering it numb ad dysfunctional. Every person who says you cannot compare the foreskin being cut off to the clitoris being cut off ….. yes, you’re right, cutting off the foreskin is FAR more damaging in terms of sensory loss than cutting off the glans clitoris. The male has no other erogenous part left to give him pleasure.

  2. The most glaring problem to me with that study was that they measured the sensitivity of the outside of the foreskin, but not the inside. I find that mindboggling. There may well be significant difference between different men, but for me the outside of the foreskin feels the same as the skin on the outside of the shaft. The inside of the foreskin is waaay more sensitive though, and there’s huge variation between different parts of the inner foreskin.

  3. Another point they missed – the elephant in the room. They established that the outside of the foreskin is no less sensistive than the rest of the penis. It is not completely numb. Only if it were completely numb would cutting it off have no effect on penile sensation.

    (In science, words ending -ivity refer to the degree to which something has a particular quality. Thus a metal has a particular electical conductivity, or its reciprocal, resistivity. Then a particular piece of that metal of certain dimensions has a conductance or resistance, that can be calculated using its conductivity or resistivity and those dimensions. This is of course now being used to an extremely fine degree in the design of electrical components.)

    Bossio et al. indeed measured the sensitivity of four points on all the penises and on the outside of the foreskins of the men who still had them. But to measure actual (sexual) sensation one would have to multipy those measures by the areas involved. (A burn with a red hot pin hurts less, and does less damage than pressing a red hot flat iron against the skin.) Clearly, the cut men woud score lower on such a measure. By focusing on those points, Bossio et al. were able to ignore that.

    Thank you for collecting together the misleading headlines. I will link to them.

  4. “The Journal of Urology® indicates that there are no differences in penile sensitivity for a variety of stimulus types and penile sites between circumcised and intact men.”

    This was their conclusive quote I think from her research. From science daily.

    1. That is correct, Kankan. Yet that statement contradicts her (their) own interpretation of the data, which says, literally: “the foreskin was significantly more sensitive to touch as compared to all the other genital sites tested”

      They can’t have it both ways. Either there are no differences, or it is significantly more sensitive. Those two statements cannot coexist. And the data supports the statement that indicates that the foreskin was significantly more sensitive to touch.

  5. I bet that only Fenner read Bossio et al. Everybody else read only Bossio’s press release. That press release (thank you Hugh Young) was a tendentious rather than fair characterisation of Bossio’s study, much closer in content and spirit to the media coverage of Bossio’s research. No journalist checks that the press release does justice to the underlying academic study.

  6. +Kankan Right, I think they measured certain parts that pertained to what they wanted to measure and test. Not just touch.

  7. At Goreden, they measured glans as well which is equivalent of clitoris. Females also have a foreksin which I learned a few years ago.

    1. Bossio and her team measured at one point outside the penis, 3 places in the circumcised penises and 4 in the uncircumcised. Touch, pain, warmth detection and heat pain were measured.

      The foreskin was detected to be significantly more sensitive to touch – which is what the Sorrells study from 2007 had already found.

  8. +Goredan I think so too, I think she wanted to measure specifically pleasure and differences in that, not just how sensitive foreskin is which is hard to measure and can’t really link to anything. I think I am getting it the more I read about it.

    1. However, Bossio’s focus was to contradict Sorrells’ study, but the only possible comparison is on the touch stimulus, and in that one the data was consistent between both studies: the foreskin is significantly more sensitive to touch.

      Since Sorrells did not measure any other type of stimulation, the data that Bossio obtained on those types of stimulation does not contradict Sorrell’s study.

    2. I don’t think she was measuring just sensitivity since we don’t know how that connects with sexual satisfaction, she was measuring and focusing mainly on other sensors that I think have more connection with actual pleasure than just what is more sensitive since that does not really tell us much. I went back and read some more.

      1. She was just measuring sensitivity, but multiple types of sensitivity, not just fine-touch sensitivity. Both she and yourself contend (without justification) that these other types of sensitivity (pain and heat) are more significant in sexual pleasure. Please explain your reasoning for this contention.

  9. Bossio’s published article ‘Examining Sexual Correlates of Neonatal Circumcision in Adult Men’ represents only a small portion ‒ and the least revealing ‒ of her more than 300 page dissertation, which one can download at

    Her conclusion in Chapter 4 (p.118) that ‘The current sample of men reported consistently high satisfaction and low levels of distress caused by their circumcision status’ is directly contradicted by her findings reported in Chapter 5 (pp. 124-165). She concludes (p.158) that ‘While intact men who participated in this study appeared to have overall better outcomes with respect to attitudes, body image, and sexual functioning, there is a sample of circumcised men who are highly distressed by their circumcision status, and these negative attitudes are associated with worse body image and sexual functioning outcomes. This paper is the first—to our knowledge—to experimentally demonstrate that there is a sample of men for which neonatal circumcision is associated with negative outcomes to their sexual lives.’ She continues with ‘This study is the first to demonstrate that attitudes towards circumcision status may be more important than circumcision status, per se, with respect to men’s body image and sexual functioning.’

    Bossio reports (p.152) ‘…(W)ithin the sample of men who participated in this study, intact men appear to consist of two possible groupings (i.e., those who are extremely satisfied or feel neutral towards being intact), while circumcised men appear to consist of three possible groupings (i.e., those who are extremely dissatisfied, neutral, or extremely satisfied with being circumcised).’

    She also reports (p.149) ‘The largest proportion of circumcised men reported feeling extremely dissatisfied with being circumcised, while the largest proportion of intact men reported feeling extremely satisfied with being intact. The more foreskin a participant reported having, the greater their self-reported satisfaction with their circumcision status.’

    Bossio acknowledges (p.155) that ‘It is possible that mixed results in the circumcision status/sexual functioning research is—at least in part—the result of a failure to control for men’s attitudes towards their circumcision status.’

    She observes (p.153) ‘This finding highlights the importance of a man’s attitude towards his circumcision status, and indicates that—at least within this
    sample—circumcised men are less likely to be happy with their circumcision status than intact men. One possible explanation for the high levels of distress among some circumcised men, and the relative importance of one’s self-reported happiness with their circumcision status, is the lack of choice in their circumcision status. The issue of choice and neonatal circumcision has been the center of a heated debate for decades.’

    She takes credit (p.158) for undertaking ‘…the first study to empirically document a sample of men who experience distress over their circumcision status.’ However, what Bossio failed to do is to delve deeper into the specific physical, sexual, psychological or self-esteem reasons why so many neonatally circumcised men would experience such distress. Those reasons were amply discussed in a survey of over 540 circumcised men and published by BJU International in 1999 as “A Preliminary Poll of Men Circumcised in Infancy or Childhood” that can be downloaded at Further light was shed on this same phenomenon by a 2012 online survey of more than 1,000 circumcised men at the Global Survey of Circumcision Harm, which can be accessed at

    While Bossio’s erroneous research about foreskin sensitivity made all the headlines, the most important ‒ yet overlooked and unreported ‒ findings, which form the crux of the circumcision debate and deserve further research, are contained in Chapter 5 of her dissertation.

  10. I think it’s a much smaller sample and would have liked it to be bigger but from the above source. There seemed to be different things being said.

    “Two large scale self report surveys on Australian populations found no difference in self-reporrted sexual functioning across circumcision status”

    “Overall, however, women and men were satisfied with their parents’s circumcision status and did not wish for it to change”

    Her conclusion was “Findings from this study indicate there is no significant between groups differences in genital response or in the subjective experience of sexual arousal” Basically, there was no difference in

    Which I think why many sites reported there being no difference.

    I think with online response, it can be tricky since it depends on who you ask and age group.

    1. There are too many issues mixed here which can be confusing.


      Those are different issues and each one can be expanded on extensively.

      Our point is that she tried to discredit Sorrells by adding variables to the measure of sensitivity, but doing that takes her study out of the scope of Sorrells and makes the results impossible to compare. However, when limited to the variable that Sorrells measured (which was fine touch sensitivity), her study confirmed Sorrells’ findings. Even if she failed to acknowledge it.

  11. That’s what I am saying, there are many things she said but I think what she was trying to do was not just focus on fine touch since that alone is not conclusive and she wanted to repeat the procedure since it looks better in research when it comes from more than one team or scientists. Replication is always good. She, as a scientist, wanted to see expand it to more than one sensory stimulation. Her conclusion was still there was really not much difference in the groups which I think is why most websites put out that as their title, to answer the question of some of the commenters. Again, I would have liked it to be done on more men.

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