Throughout scientific history, male anatomy has been considered the baseline, says Sari van Anders, PhD, a professor of psychology, gender studies, and neuroscience at Queen’s University. “In almost all areas of research, men are understood to be humans and women are understood as gender or a special case,” she says. “So, things can seem ‘complicated’ when they differ from a standard.”

Early research on women’s sexuality, such as it was, was considered unimportant or taboo. For decades, women were largely excluded from clinical trial studies. In 1953, when Alfred Kinsey published his book Sexual Behavior in the Human Female, which included nearly 6,000 personal interviews with women about their sexual activities, like masturbation practices and premarital sexual activity, the public reaction was so intense that it led to a congressional investigation into Kinsey’s funding.

Because many influential studies on sex were performed only on men, it was assumed that the way desire manifested in men was also the way it presented in women. In the early 2000s, during a graduate-level neuroanatomy class, van Anders — who was then a student — noticed that all of her course’s anatomical nerve-mapping diagrams were of men. This may not have mattered much for most of the body, she says, but when it comes to nerve endings and physical sensation, “genitals often differ quite markedly between women and men.” When van Anders approached the instructor after class and questioned whether the same nerve responses were true of women, she says he didn’t have a definitive answer. “He said some kind of mix of, ‘Yeah, I guess? Who knows? Who cares? Of course.’”

It wasn’t until the 1990s and 2000s that researchers began to study women’s sexuality seriously, says Samantha Dawson, PhD, a postdoctoral fellow at the Couples and Sexual Health Research Lab at Dalhousie University. Even then, when data began to show a divergence between men and women when it came to arousal, the unexpected findings weren’t explored further, Dawson says. Women were simply labeled as “more complicated or less intuitive.”

Noting the lack of literature on female sexuality, Nan Wise, PhD, a psychotherapist, neuroscientist, and sex therapist, decided to tackle the oversight herself. To study the female brain’s response to genital stimuli, she took fMRI brain scans of 11 women to determine which parts of the brain were activated by clitoral, vaginal, cervical, and nipple self-stimulation. Until Wise’s research, sensory mapping had only been performed on men, and as a result, researchers were unsure if the parts of the brain that correlated with female genital stimulation were the same as those associated with male genital stimulation.

In 2011, Wise and her team published their results, which identified the specific areas of the brain that were activated (or “lit up”) by clitoral, vaginal, cervical, and nipple stimulation. They discovered vaginal stimulation triggered a different brain response than clitoral stimulation, for example. But each of the areas corresponding with the various types of stimulation were within the brain’s “genital sensory cortex,” a part of the brain that receives and processes physical sensations. Prior to this study, only men’s sensory cortices had been studied. “So far, it appears that the patterns we observed for the female genitalia have a correlate in the males,” Wise says, meaning the area of the brain activated by genital stimulation is in roughly the same place in both male and female brains. However, because nipple stimulation triggered a sexual response in women and not men, this implies that the way men’s and women’s brains react to sexual stimulation does vary.

Over the past few years, researchers have also found that no one gender is more complex than the other when it comes to sexual urges. In fact, everyone is pretty sexually complicated. “We originally thought of desire as this really spontaneous thing that initiated the sexual response cycle,” says Dawson, who co-authored a 2014 study that found sexual desire emerges similarly in women and men. “We now think of desire as responsive.” Men and women, she says, report more similar levels of desire than previously thought.

“Sexuality is inherently complex, but I don’t think it’s appropriate to say one gender is more complex than another.”

It turns out that both women and men can warm up to the idea of sex after dirty talking, touching, or fantasizing, for example. Often, sexual desire does not arise in a spontaneous, animalistic manner, triggering the Masters and Johnson linear model of sexual response: desire, arousal, orgasm, and resolution. It was originally believed that only women experience this sequence out of order. The thinking followed that women didn’t naturally feel an urge for sex and could only get in the mood after dirty talking, fantasizing, or cuddling. But it turns out men also can feel desire after sex is already initiated. “This idea of responsive desire is not something that is unique to women,” says sex psychologist Justin Lehmiller, PhD.

“We [now] think the desire emerges from arousal,” and not the other way around, Dawson explains. “That change has really sparked new lines of research and led to increased questioning about whether or not arousal is gendered.”

Desire itself has also been shown to manifest similarly across gender. When both heterosexual and homosexual men and women are shown sexually explicit videos relevant to their preferences, men and women report similar feelings of desire, Dawson says. “If we give an appropriate stimulus, both [genders] report being similarly aroused.” Men and women also report similar levels of desire to have sex with a partner and masturbate, she says. “Experimentally, we can see that under the exact same conditions, men and women will perform similarly.”

Men and women also experience similar sexual fantasies. Lehmiller recently surveyed more than 4,000 Americans and found that while women fantasize more often about feeling irresistible and reassured during sex, most of the men polled reported prioritizing these feelings as well.

“If you look at the most common reasons that people report having sex, they are largely the same for men and women, and it’s primarily about pleasure,” Lehmiller says.

For decades, it was believed that higher levels of the male sex hormone testosterone increased sex drive — since men naturally possess more testosterone, it was assumed that they are inherently more cued in to sex. But emerging evidence suggests that testosterone’s impact may be less straightforward. In a 2010 study, researchers found no difference in testosterone levels in women with sexual desire disorders versus those without.

Research is also revealing additional overlap between men and women in sexual motivations. Men can seek out sex because they want to feel closer to their partners, for the intimacy — a stereotypically feminine desire — Lehmiller says. “What I’m also seeing for men is that sex often is a very emotional experience,” he says. “They need to have some intimate connection with their partner before they can feel aroused and enjoy sex and desire it.”

The idea that female desire can wax and wane throughout life is frequently cited as part of what makes women’s sexuality “complicated. It is true that many women experience a spike in desire during ovulation and in the first and second trimesters of pregnancy. And women’s sex drive can decrease during menopause. But men’s sex drive can fluctuate with age too. Stress, sleep deprivation, and depression can all cause dips in male libido.

“Sexuality is inherently complex,” Dawson says, “but I don’t think it’s appropriate to say one gender is more complex than another.”