Individual Political Attitudes and Group Norms Interact to Explain Biased Political Information Sharing

Previous research shows that people selectively share messages congruent with their political beliefs (pro-attitudinal sharing) and with like-minded others (ingroup sharing). However, it is difficult to observe how characteristics of both individual- and audience-level affect sharing decisions interactively. We address this gap by taking a cross-level, experimental approach. We recruited an online sample of Dutch residents across the political spectrum via a data panel company. Participants were introduced to 4 groups in political-themed group chats. Groups differed in political attitude (left/right) and tolerance to dissent (tolerant/punitive). Per group, participants indicated sharing intention for 4 political messages varying in their alignment with left/right-leaning political ideology. Our pilot (N = 402) and pre-registered, confirmatory main (N = 930) studies found a strong pro-attitudinal sharing effect and, to a lesser extent, ingroup sharing and pro-group sharing. Tolerant group norms increased online sharing in general, regardless of whether the message aligned with the sharer’s individual political attitude. Our findings provide causal evidence of how individual- and group-level factors affect sharing intentions of political information concurrently, and the role of tolerant general group norms to de-bias and promote online sharing. Insights taking into account both individual and group-level factors are thus required to effectively de-bias online political information sharing.