More than half of American adults own a smartphone, including some 80 percent of those in the 18 to 34 age group, a survey showed Wednesday.

The Pew Research Center's Internet & American Life Project said smartphone adoption has jumped from 35 percent in 2011 to 56 percent this year.

The survey, which polled more than 2,200 adults in April and May, found 91 percent owned some kind of mobile phone, and a majority said that phone was s smartphone or operated on a smartphone platform.

Some 35 percent said they have some other kind of cell phone that is not a smartphone, and the remaining nine percent did not own a cell phone at all, the survey found.

"As has consistently been the case since we began measuring smartphone adoption two years ago, ownership is particularly high among younger adults, especially those in their 20s and 30s," the research report said.

But every major demographic group boosted smartphone ownership between 2012 and 2013: some 69 percent of those aged 35 to 44 had a smartphone as did 55 percent of those 45 to 54.

Among those over 65 year old, 18 percent had smartphones.

"Younger adults -- regardless of income level -- are very likely to be smartphone owners," the report said.

"Conversely, for older adults smartphone ownership is more of an 'elite' phenomenon: smartphones tend to be quite prevalent at the upper end of the income distribution but much less common among those with lower income levels."

Among the survey group, 28 percent reported having an Android smartphone and 25 percent said they had an iPhone. Just four percent said they owned a BlackBerry and one percent a Windows phone.

The wealthier and more educated were more likely to report using a iPhone -- 49 percent of cell owners with a household income of $150,000 or more said that their phone is an iPhone.

The report was in line with surveys from market research firms.

According to a recent Kantar Worldpanel ComTech survey, Android, the free operating system from Google, remained the top platform with 51.7 percent of US sales to 41 percent for Apple's iOS.