Collaborative relationships, disciplinary and global culture, social identity and scientific status shape how scholars cite prior work.

Modern science is formally structured around scholarly publication, where scientific knowledge is canonized through citation. Precisely how citations are given and accrued can provide information about the value of discovery, the history of scientific ideas, the structure of fields, and the space or scope of inquiry. Yet parsing this information has been challenging because citations are not simply present or absent; rather, they differ in purpose, function, and sentiment. In this paper, we investigated how critical and favorable sentiments were distributed across citations, and tested the hypothesis that more favorable sentiment would be utilized among ingroup members, whereas more critical sentiment would be utilized toward outgroup members. We considered three group types: collaborators, those with a similar h-index, and those with the same gender. We observed that citation sentiment was more favorable to collaborators than non-collaborators, an effect that was modulated by both gender and h-index. Further, we observed that disciplinary and country-level factors impacting a scholar's perception of the size of their ingroup also explained citation sentiment: Largely experimental fields that engage in regular scholarly synthesis through review articles employed less citation sentiment, as did countries with more collectivist attitudes and greater acceptance of social hierarchies. Collectively, we demonstrated how sociocultural groups displayed ingroup preferences in the use of sentiment in scientific communication. Our study contributes to a broader understanding of how human factors influence the practice of science, and underscores the importance of considering the larger sociocultural contexts in which science progresses.