While we typically focus on data visualization as a tool for facilitating
cognitive tasks (e.g., learning facts, making decisions), we know relatively
little about their second-order impacts on our opinions, attitudes, and values.
For example, could design or framing choices interact with viewers' social
cognitive biases in ways that promote political polarization? When reporting on
U.S. attitudes toward public policies, it is popular to highlight the gap
between Democrats and Republicans (e.g., with blue vs red connected dot plots).
But these charts may encourage social-normative conformity, influencing
viewers' attitudes to match the divided opinions shown in the visualization. We
conducted three experiments examining visualization framing in the context of
social conformity and polarization. Crowdworkers viewed charts showing
simulated polling results for public policy proposals. We varied framing
(aggregating data as non-partisan "All US Adults," or partisan "Democrat" and
"Republican") and the visualized groups' support levels. Participants then
reported their own support for each policy. We found that participants'
attitudes biased significantly toward the group attitudes shown in the stimuli
and this can increase inter-party attitude divergence. These results
demonstrate that data visualizations can induce social conformity and
accelerate political polarization. Choosing to visualize partisan divisions can
divide us further