And as NPR's Aarti Shahani reports, in this story that has some colorful language, a debate brewed over what the selfie may say about females.
AARTI SHAHANI, BYLINE: In 2015, women didn't just pout their lips to do duck face. They - we - shaped the conversation.
(SOUNDBITE OF TV SHOW, "JIMMY KIMMEL LIVE!")
KIM KARDASHIAN: I think girls, to be honest, they take a lot of nude selfies.
SHAHANI: Kim Kardashian talking with Jimmy Kimmel about her new book, entitled "Selfish," replete with boob and butt shots.
(SOUNDBITE OF TV SHOW, "JIMMY KIMMEL LIVE!")
KARDASHIAN: And I think some of them, you know, I'll look back and think - God, why would I complain about, you know, feeling fat? I, you know, I liked the way I looked then. So it's taught me to be a little easier on myself.
SHAHANI: This year, Kardashian also came out endorsing the selfie stick, which by taking pictures farther away, makes you look skinnier. Comedian Amy Schumer trashed the stick.
(SOUNDBITE OF ARCHIVED RECORDING)
AMY SCHUMER: Selfie sticks are the most disgusting development that human beings have made for a long - I am so infuriated when I see someone with a selfie stick.
SHAHANI: Schumer also released a music video and hashtag, "Girl, You Don't Need Makeup," encouraging fans to post skin that's bare in a different way. Another selfie campaign, #ILookLikeAnEngineer, encouraged young women in tech to show that there are young women in tech. Women did face some serious public shaming this year for clicking away so relentlessly.
(SOUNDBITE OF SPORTS BROADCAST)
STEVE BERTHIAUME: Check it. Did that come out OK?
BOB BRENLY: That's the best one of the 300 pictures I've taken of myself today.
SHAHANI: At an Arizona Diamondbacks game, sportscasters Steve Berthiaume and Bob Brenly mocked a group of sorority sisters who were posing instead of watching the game.
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BRENLY: Every girl in the picture is locked into her phone.
BERTHIAUME: Oh, lord.
BRENLY: Every single one is dialed in. Welcome to parenting in 2015.
BERTHIAUME: (Laughter).
SHAHANI: The video got nearly 53 million views, though it omits a key detail. Right before the camera caught the selfie sisters, fans were asked to take selfies as part of a commercial promotion. And so the question arises - are selfies really a woman thing, or do men do it too, just without the same scrutiny? In November, husbands weighed in.
(SOUNDBITE OF VIDEO, "INSTAGRAM HUSBANDS")
UNIDENTIFIED MAN #1: I've had to delete all of the apps off my phone just to make more room for more photos.
SHAHANI: In this satirical video called "Instagram Husbands," men shared horror stories of a wife or girlfriend turning them into human selfie sticks.
(SOUNDBITE OF VIDEO, "INSTAGRAM HUSBANDS")
UNIDENTIFIED MAN #2: Oh, wait, just a second. I should probably comment on this. It helps me out if I'm the first one to comment.
SHAHANI: NPR tracked down the man behind this viral video, Jeff Houghton. And he says he limits himself to, like, five selfies a year.
JEFF HOUGHTON: For me, it just kind of feels weird to take a lot of pictures of myself
SHAHANI: But when asked to take out his phone and go through his photo gallery, the picture changes. It turns out he just took a selfie with his son building a Lego tower.
HOUGHTON: That was two or three days ago.
SHAHANI: Then another at a new boutique hotel.
HOUGHTON: It's a selfie of me in a bathroom with good lighting.
SHAHANI: Before that one...
HOUGHTON: Oh, someone at work had a selfie stick, and I took a picture...
SHAHANI: As we keep scrolling, the Instagram husband comes to this realization.
HOUGHTON: So maybe I'm, I don't know, I bet I'm going over my five per year idea.
SHAHANI: Yep, it looks like there may be a tad bit more.
HOUGHTON: (Laughter) You busted me. Yes, I guess there is.
SHAHANI: This year, about 2,000 scholarly articles reference selfies, according to Google Scholar, a steady uptick from prior years. Many of the papers examine women's self-representation with titles like "Virtual Lactivism: Breastfeeding Selfies And The Performance Of Motherhood."
But Terri Senft, a media scholar at New York University, says we still don't know in any rigorous way if selfies really are more of a woman thing.
TERRI SENFT: If you counted, for instance, every group party shot or every shot from a GoPro camera or every shot that includes some sort of extreme sports or guys playing instruments, I actually think that you would find a relative parity.
SHAHANI: She says it could be men and women are both into it, maybe just differently.
Aarti Shahani, NPR News, San Francisco.