Exploring the Hymen: The Virginity Question Revisited
There are a couple of obvious reasons for why such a belief might be so pervasive. The first is that when women's comfort and potentially even safety rely on providing some evidence of virginity, many women will falsify such proof - whether as backup or because they actually aren't virgins. The other is that the myth is in many ways perfectly designed for self-perpetuation. The human brain has a tendency to interpret experiences based on what it is primed to expect, so many women see bleeding after their first penis-or-other-large-object-in-vagina experience as a sign that their hymen has been broken and yet typically recognize that when bleeding happens during any subsequent event it's because of vaginal tearing (of the hymen or any other portion of the organ) due to inadequate lubrication or an inability to relax the vaginal muscles. In fact, "virgins," (or first-timers, let us say, since virginity is something of a loose concept) bleed for exactly the same reasons - tension and dryness. Women having penetrative sex for the first time are particularly prone to this because 1) your first time doing anything tends to be at least a little stressful for most people and 2) we have basically taught young women that their first time should hurt, and so when they experience discomfort many women don't stop and say, "wait a minute, I'm not wet/relaxed enough, we need to go back to the foreplay stage for a bit," but instead just grin and bear it. And when they bleed or feel something tear, they assume it's their hymen doing what it's supposed to do and not their vaginal walls tearing because you're not actually supposed to keep sticking something up there if it hurts.
But how did such an idea -that virginal women have an internal barrier that acts as physical proof of their virginity - come into being in the first place? And how universal is it really? In fact there have been many tests for virginity throughout history, some of them completely divorced from the supposed site of virginity. Some of these tests relied on magical artifacts that would respond in certain ways only to virgins. Others were based on physiological signs such as the shape of a woman's breasts (small firm breasts = virgin, large droopy breast = hooer) or the circumference of her neck (considered a physical analog of the vagina). The visual appearance or smell of a woman's urine, or the sound it made coming out of her (yes, really) was a common indicator of virginity during the Renaissance since sex was believed to "open up," a woman's genitals (sex wouldn't actually change a woman's urine in any way, but an STD could, making this one of the few tests that may have reliably identified a few unlucky non-virgins). In some southern black communities it was once believed that any bodily secretion from a man, including earwax, would cause a burning sensation when placed on the vulva of a virgin (never mind what circumstances you'd have to be in to put your earwax on some poor woman's vulva). Among the Spanish Roma, virgins are believed to have a liquid filled structure, like a small grape, inside their lady flowers that is burst upon penetration (usually in a pre-wedding ceremony conducted by a community matriarch). Since a woman's virginity is historically prized in many cultures, many methods to detect it have been thought up. And since there is no actual physiological difference between a woman who's had penetrative sex and one who hasn't, all of these methods are shaped more by cultural beliefs than by any real evidence.
The expectation of tightness and bleeding of the vagina during a woman's first sexual experience are probably the most universal beliefs about virginity, but these characteristics haven't always been coupled to the specific structure of the hymen. That happened sometime around the mid to late 16th century in Europe and seems to have spread from there, thanks to the dedicated efforts of several Medieval doctors determined to find proof of structures that could be linked to virginity, and the exact location and structure of the body part identified as the hymen was rather fluid for most of history. As it happens, tightness and bleeding aren't any more reliable than the tests described above. Modern studies have found that only about 40% of women bleed during their first sexual encounter, and it's unlikely bleeding was much more common throughout history. Perhaps one of the reasons blood has remained a staple of virginity myths is that it's easy to fake. For women in many places and many times in history, being able to "prove," virginity was essential to their honor and in some cases their lives. Women, or their families, were often expected to produce some piece of evidence post-wedding night to prove their virginity. The absence of such "proof," could lead to a woman being abandoned or worse, assaulted or killed by her new husband. Under those circumstances, a test that could be fixed is one that many women would understandably embrace.
It's impossible to say how many women throughout history have actually faked bleeding on their wedding night, but there are many known ways of doing it, some described in historical medical documents. Some of these involve inducing actual bleeding by using substances that tighten the vagina and constrict blood vessels, by creating a small injury such as a razor nick (or leech bite!) on the labia that will reopen and bleed during sex, or by timing events to coincide with a woman's menstrual cycle. Others involve substitution - placing a blood filled sponge or a blood filled organ from a small animal such as a bird or fish inside the vagina for example. In more modern times women who feel pressure to prove their virginity can use an artificial hymen or even have a hymen (or rather, a piece of tissue designed to conform to the myth of what the hymen is) surgically constructed. (As a side note, there are rare cases where the hymen does stretch across the vagina with little or no opening. That's not normal, that's essentially a medical condition that requires treatment, usually in the form of surgery and usually around the time of puberty since no opening means menstrual blood has nowhere to get out through.)
There is no such thing as physical proof of a woman's virginity. There never was and never will be, and the popular cultural image of the hymen is just as ridiculous as the urine tests and throat measurements of old. It's time we retired this one too and stopped condemning so many women to unpleasant sexual experiences because of a misrepresentation of human anatomy. There's only ever been one way to find out if a woman is truly a virgin: ask her.