A laboratory experiment examined whether one structural feature of groups—members’ physical positioning—may produce asymmetry in their perceived contribution to a task. In particular, we investigated asymmetry in group members’ (often excessive) claims of credit for collective tasks (“the self-serving attributional bias”). Consistent with the availability account of this bias, group members located in the middle of a group, with easy visual access to their partners’ contributions, demonstrated less bias than outside members (who demonstrated bias consistent with prior research)—but no less satisfaction. Further analyses suggested that these results reflected bias reduction among middle members and did stem from visual availability. We conclude that the visual constraints imposed by physical positioning influence the availability of information and thus generate asymmetric attributional bias—with implications for conflict and its reduction.