When Arielle Jardine was in first grade, all of her friends seemed to have a crush on somebody. Even her little sister, who was only in pre-school at the time, would dress up to impress one of the boys in her class. Her friends would pass notes and flirt with boys at recess, but Jardine didn't understand any of that. She had no interest in boys.

As she got older, when her friends would start talking about sex at the lunch table, Jardine would pull out her book and start reading. The idea of sex, especially with a boy, did not interest her at all.

"I thought there was something wrong with me and that I was a freak," Jardine said.

But Jardine, 19, who lives 30 miles outside Chicago, is no freak. She considers herself an asexual, a sexual orientation characterized by a lack of sexual attraction that is just beginning to be understood and studied by psychologists.

"It's a kind of absence of a traditional orientation that is straight, gay or bi, but it's still defined by one's attractions for others and therefore it's kind of the fourth quadrant - a lack of sexual attraction," said Anthony Bogaert psychology professor at Brock University in St. Catharines Canada.

A lack of sexual attraction, however, does not mean that asexuals don't experience the same kind of emotional and romantic attractions that sexual people experience, Bogaert said. A few asexuals are both asexual and aromantic (meaning they do not experience romantic attraction), but most asexuals report having at least some amount of romantic attraction for others. And this is where things get complicated.

A person who identifies as asexual may also identify as heteromantic, homoromatic or biromantic. Likewise, someone who is heterosexual or homosexual may identify as aromantic. And just because someone identifies as asexual does not mean that he/she does not experience sexual arousal, which is different from attraction.

"There can be a kind of disconnect between what's going on in people's heads, and what's going on in their bodies," Bogaert said.

Most Asexuals do, in fact, experience sexual arousal, and many of them masturbate as a form of what Bogaert calls non-specific sexual desire, where they do not connect their sexual desire to other people. According to Jardine some asexuals even enjoy sex, which she said is different from sexual attraction, because they experience pleasure during the act but lack sexual attraction outside of that.

Findings like these have prompted some psychologists to adopt an air of skepticism around the subject. Northwestern University psychology professor Michael Bailey is among those who disagree with Bogaert's research.

"I think it is unlikely that there exist people without sexual motivation or orientation, and it will take strong evidence before I'll believe otherwise," Bailey said. "Such evidence doesn't yet exist."

All of these complications have made things even more difficult for Jardine to grapple with, because less than a year ago, she came out as homoromantic, which means she is romantically attracted to girls despite lacking any sexual attraction.

"It was hard. My mom asked over and over if I was a lesbian because she knew I had no crushes and she thought I was [a lesbian]," Jardine said. "She was kinda right, at least in the romantic sense."

Things first changed for Jardine the day she stumbled across asexuality.org, the URL that houses the Asexual Visibility and Education Network (AVEN), the world's largest online asexual community.

"I joined the site right away, and it felt so great to know I was not alone, that there were others like me," she said.

The site, which was founded in 2001 by David Jay while he was a student at Wesleyan University, serves as a meeting ground for outsiders from around the country perplexed by their lack of sexual interest.

Univeristy of Illinois at Urbana-Champaign graduate student Andrew Hinderliter, who also identifies as asexual, first found AVEN during his first semester of graduate school in 2007. Hinderliter quickly become fascinated with the site spending hours every day perusing the site's forums and discussion boards.

"I wanted to learn as much as possible, but it was frustrating that there wasn't much out there," Hinderliter said.

His frustrations with the lack of information available lead him to begin conducting his own research. He delved deep into the AVEN archives and scoured dozens of older internet sex forums. Soon his passion merged with his studies. He is currently researching the development of ideas and identities in asexual communities over time, and the vocabulary that people devise for doing so at the University of Illinois
at Urbana-Champaign.

He has found that the asexual community is surprisingly diverse. Asexuals have developed a number of labels to identify themselves along what they see as a spectrum of sexual attraction. Demi-sexuals, for example, do not experience sexual attraction until they form a strong emotional connection with another person, and someone who identifies as Gray-A does not normally experience sexual attraction, but does experience it sometimes.

The biggest thing Hinderliter has noticed, however, is the increase in visibility. Membership on AVEN and similar sites has grown dramatically, and an increasing number of blogs and tumblrs are devoted to chronicling individual experiences with asexuality. Hinderliter attributes the uptick in part to an acceptance among established LGBT organizations who have recognized asexuality as a legitimate sexual orientation.

It's not that more asexuals exist today than 20 years ago--they just have something to call themselves now, Hinderliter said.