Biased collective memories and historical overclaiming: An availability heuristic account.

People tend to overclaim historical influence for their own ingroup, in a phenomenon called ingroup inflation. Although this overclaiming has been empirically demonstrated in the USA and other nations, the cognitive mechanisms underlying it have been largely conjectural. We test one such proposed mechanism: the application of the availability heuristic to a biased collective memory. Collective memories in the psychological sense are shared memories held individually by members of a group that pertain to their group identity. Using measures of retrieval fluency, we show that asymmetrical accessibility for collective memories favoring ingroup - versus outgroup - relevant historical events is correlated with overclaiming, and that reducing this asymmetry through targeted retrieval of outgroup-relevant events reduces overclaiming (Experiments 1 and 2). We also suggest that ingroup inflation arises because of retrieval fluency per se, rather than more stable asymmetries in knowledge or event-specific judgments of importance (Experiment 3). Together, these studies suggest some cognitive bases of collective overclaiming and cognitive interventions that might attenuate these biased judgments.