Arousal is different for everybody, in other words, even among those who happen to be of the same gender identity or sexual orientation, and what's true for an individual at one point in time is very likely to change as the years pass and relationships evolve (and innovations like so-called female Viagra — which got a big push for FDA approval — pop up).
In spite of all the researchers these days attaching electrodes to genitals and forcing people to watch naked yoga, in some ways the sources and varieties of human pleasure remain as mysterious as ever.
You've likely heard that pornography can be destructive for real-life relationships. Too much porn, the thinking goes, desensitizes the viewer to erotic images and makes it more difficult to become aroused in real-life sexy situations. Some have even claimed that men who frequently watch online porn are more likely to struggle with erectile dysfunction. Earlier this year, however, a pair of studies were published that found no correlation between porn viewing and erectile dysfunction. Other research has even suggested that both men and women with a casual porn habit report having more frequent and higher-quality sex compared with people who don't watch porn.
2. Bisexual men tend to be more sexually adventurous over all than gay or straight men.
Previous research had suggested that bisexual men's bodies respond more strongly to erotic images of men than to those of women, a finding that contributed to the (unfair and outdated) skepticism over whether bisexuality is a distinct sexual orientation. But a 2013 study highlighted a key characteristic that may explain why some bi men get turned on by women and some don't: sexual adventurousness. Bisexual guys who are drawn equally to men and women tend to score higher in sexual curiosity — in other words, they show more interest in a wider range of sexual acts. The authors argue that this means that, even within the seemingly discrete category of "bisexual men," there is a fair amount of sexual fluidity.
3. As viewers of The Kids Are All Right may remember, some lesbians like to watch gay-male porn.
In case you needed more proof that human sexuality is an often unpredictable thing, there's a study by Irish and Canadian researchers in which they interviewed lesbians about their porn preferences. Most of the women quoted didn't care for girl-on-girl porn, saying they found the films unrealistic and clearly made by and for straight men. ("For the guys, it's like, Oh, make them both cute and femme, because they don't want to have this masculine dyke in there," said one woman after watching a clip from Lesbian Cheerleader Squad 2.) Instead, many lesbians are drawn to erotic films depicting two guys getting it on. That's partially because women tend to have more erotic plasticity than men — that is, they're turned on by a wider variety of things. Sex researcher Meredith Chivers has found, for example, that while men tend to show physical arousal only in response to erotic films depicting their stated sexual orientation, women show similar arousal patterns when watching clips from gay-male, lesbian, and straight pornography, regardless of their orientation. (Plus, with guy-on-guy porn, you don't have the associated ickiness of women performing for a male audience.)
4. "Female Viagra" releases the brain's sexual brakes.
The drug flibanserin, intended to treat low sexual desire in women, isn't exactly the pink version of the little blue pill. Rather than pushing blood flow to the genitals, flibanserin targets key neurotransmitters that are involved in sexual response: dopamine, norepinephrine, and serotonin. The drug increases the amount of dopamine and norepinephrine, which are like the brain's accelerators when it comes to sexual response; at the same time, it turns down the level of serotonin, which is responsible for inhibition. Since 2010, the FDA has twice shot down flibanserin. Each time, the drug manufacturers couldn't prove to a review panel that the medication's benefits were greater than the risks it posed. Flibanserin gets a third chance at approval this summer — this month, an advisory panel was convinced that flibanserin is safe to use for women taking antidepressants and that the drug does not impair driving; the FDA won't make the final decision until August, but the committee's vote is highly influential.
5. Many transgender men and women experience changes in their sexual desire as they transition.
About 71 percent of transgender men report an increase in desire after sex-reassignment therapy, according to a 2014 study in the Journal of Sexual Medicine. "Trans men take testosterone, and testosterone really, really will increase the sex drive," said Stefan Rowniak, a nurse-practitioner and assistant professor at the University of San Francisco. The opposite is often true for transgender women, 62 percent of whom say their sexual desire drops after the therapy. And sometimes, but certainly not always, transgender people experience other changes in arousal while transitioning, such as whom they're aroused by. A 2014 study by German researchers found that 33 percent of trans women and 22 percent of trans men reported a change in their sexual orientation after transitioning — that is, some were now attracted to men, or women, or both, in ways they weren't before. Then again, plenty of post-transition transgender folks would prefer to keep sleeping with the same types of people as they did pre-transition — and for some, the sex gets much better. As one trans man told Rowniak about sex with his husband after transitioning, "The interesting part of being sexual with him as a man was [that it's] much better than being sexual with him as a woman, even though the act was pretty much the same."
6. Jerry Seinfeld was right: There's good naked, and there's bad naked.
Meredith Chivers is somewhat famous in her field for showing study subjects a wide range of visual stimuli in order to assess what kind of imagery tends to get people going. In one study, her human lab rats watched all sorts of films, including some of people exercising naked. Set to background music, those movies depicted a lone nude person doing yoga,calisthenics, or simply walking. These were the least popular of all the films, resulting in the weakest arousal response.
7. One percent of the population likely isn't turned on by anything at all.
The science on asexuality has picked up lately. Last year, scientists at the University of British Columbia examined whether people who say they are asexual really just have extremely low sexual desire. They don't. On the contrary, asexuality, like homosexuality or heterosexuality, seems to be a distinct sexual orientation. This year, that same research team developed a 12-item survey that, they argue, can identify asexuals. It's called the Asexuality Identification Scale
, or AIS for short, to mimic the nickname some asexuals give themselves: aces.
8. Zoophilia may be the most common uncommon turn-on.
Researcher Justin Lehmiller last year ran a survey for readers of his popular blog, Sex and Psychology
, asking them to share the "most unusual" things that make them sexually aroused. As Lehmiller combed through the answers, a theme emerged: sexual attraction to animals, horses especially
9. Oysters are a sham.
Although many foods have been touted as aphrodisiacs, there is little to no scientific evidence that any of them, including oysters, actually boost sexual desire. Most people who swear by aphrodisiacs have probably just experienced a change in sexual desire because they strongly believed that they would. Put that way, pretty much anything can be an aphrodisiac if you want it to be.