In a study of 139 women who had experienced intercourse with a number of both circumcised and uncircumcised partners, O’Hara and O’Hara (1999) found most (73%) reported that circumcised men thrust harder and deeper, and used more elongated strokes than their uncircumcised counterparts. The majority of the respondents preferred sex with uncircumcised males, citing greater displacement of vaginal secretions and resulting vaginal dryness, increased friction, and physical discomfort during intercourse with men that were circumcised. Among the minority of respondents who preferred circumcised partners (N = 20), the most common reason given was prolonged intercourse. But complaints about the loss of vaginal secretions, friction, and discomfort were still prevalent in this group. Perhaps due to reduced penile sensitivity, circumcised men thrust deeper and withdraw farther and thereby displace more vaginal fluids. O’Hara and O’Hara conclude that the loss of vaginal lubrication and discomfort is “because of the tight penile skin, the corona of the glans, which is configured like a one way valve, pulls the vaginal secretions out of the vagina when the shaft is withdrawn” (p. 82) Therefore, although practiced primarily for religious and/or hygienic reasons, an unintended consequence of circumcision may be to enhance the semen displacement properties of the human penis.