<p>We conduct a hybrid experimental–observational study on college students to examine how institutional quality and social identity cues jointly shape behavior in a corruption experiment. A between-subject design varies the availability of information on participants’ geographic origin and whether matches occur within or across macro-regions. In the absence of geographic information, individuals from areas with lower contemporary and historical civic capital are significantly more likely to engage in corruption, consistent with internalized norm differences. Once geographic origin is revealed, this effect disappears and behavior is driven by the salience of group boundaries. In particular, revealing regional identity increases corrupt behavior primarily in out-group matches, reflecting strategic adjustment to perceived coordination prospects. These results suggest that while institutional quality leaves a lasting imprint on prosocial norms, salient group cues can crowd out internal motivations and redirect behavior toward strategic responses to social boundaries, underscoring the role of institutional and informational environments—and the policy relevance of social identity salience—in shaping corruption-related behavior.</p>