As smartphone penetration among US teens rises, those devices insinuate themselves more and more into that age group’s daily lives. Indeed, smartphones are so omnipresent that teens themselves doubt whether this is altogether a good thing.

With the image of teens obsessively using smartphones now a cliché, it is easy to forget that they were slow to acquire the device—or, more precisely, to have their parents provide one. As recently as 2012, polling by Common Sense media found just 41% of 13- to 17-year-olds had a smartphone. For that matter, they still lag somewhat behind millennials and Gen Xers. However, most now have one. We estimate that 81.1% of 12- to 17-year-olds will have a smartphone this year, with the number expected to reach 85.0% in 2022.

In a telling sign of the degree to which a smartphone is now a basic necessity of life for teens, there is little variation in smartphone penetration along lines of family income. Common Sense Media polling in March and April 2018 found 88% of teens in lower-income families had a smartphone, as did 87% in middle- and 92% in upper-income families. As noted in a new eMarketer report, "Digital Life of US Teens: Teens Text, Snap, Game and View Video, and Their Favorite Device is a Smartphone," there is also scant variation in gender or ethnicity.

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On the latest episode of Behind the Numbers, eMarketer analyst Mark Dolliver discusses the digital life of a teen. How many of them have smartphones? What social media do they use? Which video platforms do they spend the most time with? And how do they feel about advertising?

Of course, plenty of adults spend plenty of time using their smartphones. What is distinctive in teens' usage is the degree to which it dominates their overall digital activity. Research by Verto Analytics in H1 2018 showed mobile time accounting for 62% of the total time 13- to 17-year-olds spent using mobile devices and desktop/laptop computers. Among adults, mobile usage accounted for 41% of the total.

Even teens wonder whether their smartphone usage is excessive. In April 2018 polling of 13- to 18-year-olds in the US by Screen Education, respondents estimated on average that 60% of their friends are “addicted” to their phones. Assessing themselves, 65% said they “wish they had a better ability to self-limit the amount of time they spend on their phone.”

Though they find it hard to put their phones down, teens do not always find its presence benign. In the Screen Education polling, 41% said they feel “overwhelmed every day by the quantity of notifications they receive.” When they are with friends, phone usage can also yield stretches of time in which they all sit silently staring at their own phones.

Then again, the temporary absence of their phone can be troubling for teens—girls more so than boys. In Pew Research Center polling in March and April 2018 among 13- to 17-year-olds, 49% of the girls and 35% of the boys said they feel “anxious” when they don’t have their mobile phone. Likewise, 32% of the girls and 20% of the boys said they feel “lonely” in that situation.

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