What does it mean to “go online,” anymore? A huge number of people are there, wherever there is, pretty much all the time.

One-fifth of Americans is online “almost constantly,” according to a new survey by the Pew Research Center, with perma-connectedness particularly pronounced among younger demographics. More than one-third of people between the ages of 18 and 29 reported being online nearly all the time, while just 6 percent of people over 65 said the same about their Internet habits.

Smartphones play a crucial role here, not surprisingly. “Among Americans who don’t use a mobile device as their way of getting on the Internet,” Pew wrote, “just 8 percent report that they go online almost constantly.”

Adults with higher levels of education and higher incomes were also more likely to report near-constant activity online. Men and women were equally likely to say they were online pretty much all the time; black people were slightly more likely to say the same, compared with respondents who identified as white or Hispanic.

Much of Pew’s other recent research meshes with these findings. Americans are increasingly using smartphones to search for jobs, manage finances, read books, shop, and socialize. And the population of Americans who don't use the Internet at all has dwindled to 15 percent.

Many of the demographic qualities that make someone less likely to report near-constant connectivity are the same for people who never use the Internet: People who have lower levels of income and education, those who are older than 65, and those who live in a rural areas are all less likely to go online—constantly, or altogether.