A few weeks ago, after I said goodbye to a friend who was moving across the country, I texted her an emoji of a crying face. She replied with an image of chick with its arms outstretched. This exchange might have been heartfelt. It could have been ironic. I’m still not really sure. It's possible that this friend and I are particularly emotionally stunted, but I put at least part of the blame on emoji: They allowed us to communicate without saying anything, saving us from spelling out any actual sentiments. It’s no surprise that millenials have embraced emoji and their pixelated cousins, emoticons. Ambiguous, superficial, and cute, they’re perfectly suited to a generation that sends Hallmark e-cards ironically, circulates step-by-step guides to “being deep,” and dismisses “deep meaningful conversations” as “DMC’s.”

Writers around the Internet are giddy at the prospect of the 250 new emoji characters coming out later this month. Last Monday, news broke of a soon-to-launch social network, “emojli,” on which users will communicate only through emoji; two days later, over 50,000 people had already reserved usernames (consisting, of course, of strings of emoji). Some enthusiasts even believe emoji have literary potential. After raising $3,500 on Kickstarter, data engineer Fred Benenson set out to translate every line of Moby Dick into emoji. Using Amazon’s crowd-sourcing project Mechanical Turk, Benenson managed to find thousands of strangers willing to work on the project. Three people translated each line of Melville’s text; a second group selected the best translation of the three. Benenson sells the finished product—"Emoji Dick"—online, for $200 in hardcover. (The merely curious can opt for a $5 PDF.) Last year, the Library of Congress requested a copy. Benenson says he pockets between $100 and $300 a month from sales.

Emoticons and emoji are changing the way we communicate faster than linguists can keep up with or lexicographers can regulate. “It's the wild west of the emoji era,” said linguist Ben Zimmer over the phone. “People are making up the rules as they go. It’s completely organic.”

At the forefront of the research into emoji use today is Stanford-trained linguist Tyler Schnoebelen. By analyzing emoticon use on Twitter, Schnoebelen has found that use of emoticons varies by geography, age, gender, and social class—just like dialects or regional accents. Friend groups fall into the habit of using certain emoticons, just as they develop their own slang. “You start using new emoticons, just like you start using different words, when you move outside your usual social circles,” said Schnoebelen. He discovered a divide, for instance, between people who include a hyphen to represent a nose in smiley faces— :-) — and people who use the shorter version without the hyphen. “The nose is associated with conventionality,” said Schnoebelen. People using a nose also tend to “spell words out completely. They use fewer abbreviations.” Twitter notoriously obscures demographic data, but according to Schnoebelen, “People who use no noses tend to be tweeting more about Miley Cyrus, Justin Bieber. They have younger interests, younger concerns, whether or not they’re younger.”

The gender divide in emoticon use is another topic of debate. “Based on the ideology that women are more emotional, the normal claim is that women use more emoticons,” said Schnoebelen. He’s quick to point out that analyzing emoticon use—or any linguistic pattern—along a gender binary is simplistic, but studies suggest that women account for a disproportionate amount of emoticon use. In 2012, a team of psychologists at Rice University gave 21 college students—eleven male, ten female—free iPhones they could monitor, without telling their subjects the purpose of the experiment. Over the course of the next six months, the researchers collected and analyzed about 124,000 text messages sent by the group. Everyone involved in the study sent an emoticon at least once, though most people used them infrequently: Just 4 percent of all text messages contained an emoticon—and these were twice as likely to be sent by a woman.