The intromission function of the foreskin
Introduction
Morgan [1], [2] stated that vaginal intromission is easier with a (retractable) foreskin in place. However, no one has experimentally tested his contention or clearly explained the mechanism. There are no contradictory claims in any of the citations to Morgan's letters. Harnes (3) published a `fruitless' attempt with a questionnaire to evaluate Morgan's claim of greater sexual pleasure with a foreskin. Articles about circumcision and evolutionary antecedents of human sexuality have almost totally neglected the even more general question: the function of the foreskin. The recent position paper of the American Pediatrics Association is silent on this issue (4). A heated debate in the New England Journal of Medicine produced no references and only a single sentence regarding the function of the foreskin, `...protection of the sensitive glans' (5). Porter and Bunker (6) in an article entitled, The dysfunctional foreskin, say only `...its function – physically, physiologically and immunologically protective of the glans and external urethral orifice.'
Several recent publications have considered evolutionary antecedents of human sexual behavior and unusual primate male genitalia but they do not mention the foreskin or prepuce [7], [8], [9]. Money (10) cites a survey finding that the foreskin is a `visual and tactile erotic organ.' Cox (11) postulates, without evidence, that the foreskin retards the age of sexual reproduction. There is little in the older literature they missed. Even in an article entitled, `Observations on the evolution of the genitalia and copulatory behaviour in male primates, (12) there is no mention of the foreskin or prepuce! All the Textbook of Sexual Medicine (13) says, without references, is `There is much controversy and little data surrounding the question of the effect of circumcision on male function.'
Section snippets
Evidence
Preliminary measurements of the force required for intromission with and without the benefit of the foreskin have been made with a simple device. The device consisted of a Styrofoam cup the bottom of which was cut to make a flexible artificial introitus. The cup was mounted on a diet scales so that the force being applied could be noted (Fig. 1). Twelve measurements were made with the glans penis alternately exposed or covered by the foreskin. Intromission with the glans exposed required a
Discussion
These preliminary findings support the claim by Morgan [1], [2] that vaginal intromission is easier with a (retractable) foreskin in place. The mechanism is simple. The interposed foreskin decreases the friction between the introitus and the glans. The unretracted foreskin consists of a thin dermis that is folded on itself with very little friction between the layers. As the penis advances, the foreskin unrolls so that the portion that makes initial contact with the introitus is 6 cm. Up the
References (23)
- et al.
The evolution of human sexuality
Trends in Ecology and Evolution
(1996) De Virginibus Puerisque: The function of the human foreskin considered from an evolutionary perspective
Medical Hypotheses
(1995)The rape of the phallus
JAMA
(1965)Penile plunder
Med. J. Aust.
(1967)The foreskin saga
JAMA
(1971)- American Academy of Pediatrics. Circumcision policy statement. Pediatrics...
Neonatal circumcision
NEJM
(1990)- et al.
The dysfunctional foreskin
Int. J. of STD & AIDS
(2001) The Third Chimpanzee: The Evolution and Future of the Human Animal
(1992)The Last Ape: Pygmy Chimpanzee Behavior and Ecology. Translated by Evelyn Ono Vineberg
(1992)
Sexology, body image, foreskin restoration and bisexual status
Journal of Sex Research
Cited by (19)
Attempting to trace the origins of circumcision
2019, Journal of Pediatric SurgeryReply to Letter to the Editor
2018, Journal of Pediatric SurgeryMale genital mutilation: an adaptation to sexual conflict
2008, Evolution and Human BehaviorCitation Excerpt :Miscellaneous findings can be used to suggest potential mechanisms by which circumcision may impact competition for fertilizations. These include increased effort required to overcome friction during intromission (Taves, 2002); desensitization of the penis, raising the threshold for sexual arousal (Immerman & Mackey, 1997; Sorrells et al., 2007); increased latency to ejaculation (Senkul et al., 2004), which would especially hinder hasty covert copulations; decreased stimulation of the female, potentially impacting cryptic choice (O'Hara & O'Hara, 1999); an 8-mm decrease in mean length of the erect penis associated with circumcision (Richters, Gerofi, & Donovan, 1995); elimination of sex pheromones produced by the preputial mucosa (Immerman & Mackey 1997); and disruption of neural feedback involved in adaptive modulation of copulation dynamics (Cold & Taylor, 1999). These mechanisms are wholly speculative, based on limited observations.
Male circumcision - see the harm to get a balanced picture
2007, Journal of Men's Health and GenderThe case against circumcision
2007, Journal of Men's Health and GenderThe initial interplay between HIV and mucosal innate immunity
2023, Frontiers in Immunology