One-in-five adults do not use the internet. The difference between that group and the majority of Americans who do go online remains strongly correlated with age, education, and household income, which are the strongest positive predictors of internet use.
Certain aspects of the current internet population still strongly resemble the state of internet adoption in 2000, when one of Pew Internet's first reports found that minorities, adults living in households with lower incomes, and seniors were less likely than others to be online.
Yet while gaps in internet adoption persist, some have narrowed in the past decade. The internet access gap closest to disappearing is that between whites and minorities. Differences in access persist, especially in terms of adults who have high-speed broadband at home, but they have become significantly less prominent over the years.
Almost half of adults don't use the internet because they don't think the it is relevant to them -- often saying they don't want to use the internet and don't need to use it to get the information they want or conduct the communication they want.
Read the full report, Digital Differences: For Some Groups Disparities in Internet Use Remain, on the Pew Internet & American Life Project website.