The enduring power of social context: Pre-war contact opportunity amplifies the effects of post-war contact.

Intergroup contact is one of the most established approaches for improving relations between adversary groups in conflict settings; yet little is known about whether its effects might be shaped by the social context. In this paper, we examine whether pre-war contact opportunity with the adversary group shapes the relationship between post-war intergroup contact and willingness to engage with the adversary group, measured at two post-war time points. We operationalize pre-war contact opportunity objectively, using pre-war census data on adversary group share. We analyse data from two studies conducted in post-war Bosnia and Herzegovina. Study 1, conducted approximately 10 years after the war's outbreak (N = 1967), demonstrates that post-war intergroup contact is more strongly associated with contact willingness among individuals who, before the war, lived in municipalities with higher contact opportunity. Study 2, conducted more than 30 years after the war, does not provide evidence for the same moderating pattern (N = 330), but supplementary analyses indicate persistent significant yet attenuated effects of contact opportunity. These findings highlight the relevance of the pre-conflict social context and temporal dynamics for understanding intergroup contact effects in post-conflict societies.