  Homophily refers to the tendency of individuals to associate with others who
are similar to them in characteristics, such as, race, ethnicity, age, gender,
or interests. In this paper, we investigate if individuals exhibit racial
homophily when viewing visualizations, using mass shooting data in the United
States as the example topic. We conducted a crowdsourced experiment (N=450)
where each participant was shown a visualization displaying the counts of mass
shooting victims, highlighting the counts for one of three racial groups
(White, Black, or Hispanic). Participants were assigned to view visualizations
highlighting their own race or a different race to assess the influence of
racial concordance on changes in affect (emotion) and attitude towards gun
control. While we did not find evidence of homophily, the results showed a
significant negative shift in affect across all visualization conditions.
Notably, political ideology significantly impacted changes in affect, with more
liberal views correlating with a more negative affect change. Our findings
underscore the complexity of reactions to mass shooting visualizations and
suggest that future research should consider various methodological
improvements to better assess homophily effects.
