  Intergroup contact has long been considered as an effective strategy to
reduce prejudice between groups. However, recent studies suggest that exposure
to opposing groups in online platforms can exacerbate polarization. To further
understand the behavior of individuals who actively engage in intergroup
contact in practice, we provide a large-scale observational study of intragroup
behavioral differences between members with and without intergroup contact. We
leverage the existing structure of NBA-related discussion forums on Reddit to
study the context of professional sports. We identify fans of each NBA team as
members of a group and trace whether they have intergroup contact. Our results
show that members with intergroup contact use more negative and abusive
language in their affiliated group than those without such contact, after
controlling for activity levels. We further quantify different levels of
intergroup contact and show that there may exist nonlinear mechanisms regarding
how intergroup contact relates to intragroup behavior. Our findings provide
complementary evidence to experimental studies in a novel context and also shed
light on possible reasons for the different outcomes in prior studies.
