Political polarization has increased most among the groups least likely to use the internet and social media, Brown research finds.

PROVIDENCE, R.I. [Brown University] — Despite the popular narrative that the web is to blame for rising political polarization, a study by a Brown University economist has found that recent growth in polarization is greatest for demographic groups in which individuals are least likely to use the internet and social media. In other words:

This means that data does not support the claim that the internet is the most significant driver of partisanship.

“We find that the groups least likely to use the internet experienced larger changes in polarization between 1996 and 2016 than the groups most likely to use the internet,” said Jesse M. Shapiro, professor of economics at Brown and coauthor of the study along with Levi Boxell and Matthew Gentzkow from Stanford University.

The study, titled “Greater Internet use is not associated with faster growth in political polarization among U.S. demographic groups,” appears today in the Proceedings of the National Academy of Sciences. The study expands on research that appeared as a working paper in March and includes data for the 2016 presidential election.

Shapiro and his coauthors measured political polarization among Americans using data from the American National Election Study, a nationally representative, face-to-face survey of the voting-age population that has been conducted both pre- and post-election since 1948 and collects data on Americans’ social backgrounds, political predispositions, social and political values, perceptions and evaluations of groups and candidates, and other issues. The authors also utilized survey microdata on social media use from the Pew Research Center that covers the years 2005, 2008, 2011, 2012 and 2016, as well as from every presidential election year between 1996 and 2016.

Shapiro and his coauthors assessed whether demographic differences, in particular age, impacted trends in eight measures of political polarization, ranging from straight-ticket voting to partisan affect polarization — the tendency of people identifying as Republicans or Democrats to view opposing partisans negatively and co-partisans positively.

For all but one of the eight measures of polarization, the increase was larger for the older group than for the youngest group. This is important because age is a strong predictor of internet and social media use.

Less than 40 percent of those 65 and older and less than 20 percent of those 75 and older reported that they obtained information about the 2016 presidential campaign online. In contrast, over 75 percent of 18 to 39-year-olds got information about the 2016 presidential election online.

Within the 65+ age group, partisan affect polarization, which the authors identify as an especially important measure, grew at three times the rate it did for those aged 18 to 39.

While the researchers do not rule out that the internet has played some role in the recent rise in polarization, these facts can be shown to imply a limited role for the Internet and social media in explaining the recent rise in measured political polarization, Shapiro said.