The Pew survey, conducted in September, found that 52 percent of Internet users regularly logged on to at least two social networks, up from 42 percent in Pew’s August 2013 survey.
The percentage of adults using Facebook, the most general social network, stayed about the same, at 71 percent of the online population. But Pew found significant increases in the number of people using Instagram, a photo service owned by Facebook; Pinterest, a visually oriented service for “pinning” favorite items; LinkedIn, a business networking service; and Twitter, a microblogging service oriented toward real-time news and information.
Facebook users were the most dedicated, with 70 percent logging in at least once a day. Nearly half of Instagram users visit the site daily.
Twitter, which has reported slow user growth in recent quarters, saw fewer visits from its American users, according to the Pew study. Only 36 percent of them visit the site daily, the researchers found, compared with 46 percent in the 2013 survey.
In a statement after the survey data was released, Twitter disputed the findings, saying, “Pew’s data is so wrong as to be laughable. As we said at our Analyst Day in November, 48 percent of our monthly active users in our top 20 markets use the service daily, and the U.S. is our top market,” said Rachel Millner, a Twitter spokeswoman.
LinkedIn users also said they visited the site less frequently, although a dedicated core of 13 percent said they went at least once a day.
The Pew research surveyed 2,003 adults, including 1,597 Internet users, by cellphone and land line. It has a margin of error of plus or minus 2.5 percentage points.
What the numbers don’t reveal was the time people spent on each service. Because most social networks generate revenue from advertising, more time on the service means a greater opportunity for visitors to see ads.
But the researchers did learn that for the median Facebook user, two-thirds of his or her friends weren’t “actual” friends at all. And less than half of adult Facebook users have friended their parents or children on the service.
An earlier version of this post misstated the number of Internet users surveyed by Pew. It was 1,597, not 2,003.