In the last few years, scientists have conducted an unprecedented amount of research on sexual arousal and desire in women. The fact that sex researchers are finally starting to give women’s issues the attention they deserve is undoubtedly great news. Unfortunately, the way some results of this research are being reported in the media is, for the most part, all wrong.

The effect is that much of what people think they know about women’s sexuality just isn’t true. Take, for instance, the popular stereotype that no woman is completely heterosexual. It’s easy to find news reports touting science to support the claim. Case in point: a recent headline in The Telegraph proclaimed “women are either bisexual or gay, but ‘never straight’,” while one by the BBC argued that “no woman [is] “totally straight’.” These articles discuss the results of the same study, which found that the vast majority of straight female participants showed signs of sexual interest in both male and female targets.

Several recent studies have demonstrated a similar pattern of effects, most of which involved looking at how women’s genitals respond when viewing different kinds of pornography. Here’s how these studies often work: a small device is inserted into the vagina to measure changes in blood flow to the genitals. Participants then watch various kinds of porn and, as their genital responses are recorded, they also complete a survey on how aroused they feel.

People don’t always tell the truth on surveys, especially sex surveys.

What researchers typically see among women who identify as heterosexual is a “nonspecific” genital response pattern, meaning these women tend to show significant signs of genital arousal regardless of whether they’re watching porn that features male actors or female actors. When you look at women’s survey responses, though, they’re quite different, with women self-reporting that they’re far more aroused by the male imagery than by the female imagery.

By contrast, when men who identify as heterosexual go through a similar procedure, their erectile responses and survey responses are more consistent with each other, with both primarily signifying sexual interest in female targets.

On the surface, these results might appear to support the claim that no woman is 100 percent straight, especially if you believe that our genitals are the accurate measures of our sexual orientation. After all, people don’t always tell the truth on surveys, especially sex surveys.

The idea that genital arousal measures are a sort of sexual polygraph is appealing because it makes interpreting research easier: whenever there’s a disconnect between what someone says on a survey versus the results of a genital arousal measure, one can just disregard the former and chalk it up to people being liars—or not knowing what they want.

This is a problematic way of thinking, however, for several reasons. First, it’s important to recognize that—for both women and men—measures of genital arousal and psychological arousal sometimes tell us two different things, so we can’t always expect them to line up. For example, we know that men experience penile erections and women experience clitoral erections at night as they move in and out of different sleep cycles. This leads many of us to wake up showing signs of genital arousal—so-called “morning wood”—without necessarily feeling aroused or wanting sex. At other times, however, we may feel turned on, but our genitals just don’t respond the way we want them to for a variety of reasons, including age, performance anxiety and alcohol use.

We can’t just look at how someone’s body responds and draw sweeping conclusions about their underlying desires.

As these examples illustrate, if you only use one type of measure and disregard the other, it would be easy to come to flawed conclusions about when we’re turned on and what we desire.

But that’s not the only problem; if we were to accept that genital arousal measures somehow tell the truth about what women really want, we would also have to accept that women are generally turned on by nonhuman primates, thanks to studies that have found women to show genital arousal in response to videos of bonobos having sex. We would also have to accept the idea that women are turned on by sexual-assault scenarios, given research showing that women experience genital arousal in response to depictions of rape.

This logic just doesn’t make sense, and it has led scientists like Dr. Meredith Chivers to conclude that “sexual identity…sexual attraction…and sexual response…are not interchangeable constructs in women, such that a woman’s sexual desires and attractions can be deduced from sexual response patterns.”

Chivers’s preferred analogy here is to think about how a vegan might salivate at the smell of bacon. Just because they’re salivating doesn’t mean they actually want to eat it. In other words, we can’t just look at how someone’s body responds and draw sweeping conclusions about their underlying desires.

Of course, all of this begs the question of “why.” Specifically, why do we see a disconnect between women’s genital responses and their survey responses? That’s something we don’t yet know, and many scientists, including Chivers, are working to understand it.

One theory is that women evolved to experience genital arousal more quickly than men in order to reduce physical trauma from forced sex. The thought here is that because sexual assault against women has been an unfortunate reality throughout human history, perhaps fast vaginal lubrication evolved in order to help protect women from genital injuries. To the extent that this is true, it could help to explain the frequent disconnect we see between women’s genital arousal and their self-reported sexual arousal.

While we still have much to learn, one thing is clear: arousal studies most certainly do not prove any one woman’s sexuality—or the stereotype that all women are inherently bisexual.


Justin Lehmiller, PhD is a sex educator and researcher at Ball State University, a Faculty Affiliate of The Kinsey Institute, and author of the blog Sex and Psychology. Follow him on Twitter @JustinLehmiller.