Observation inflation as source confusion: Symmetrical conflation of memories based on action performance and observation.

People often cannot remember the source of their memories despite recalling other elements of a remembered event correctly. Observation inflation is one such error of source monitoring. It refers to remembering the actions of another agent as self-performed. While the existence of this memory error is well documented, it is not clear how it relates to other errors of source attribution: It is not evident whether the phenomenon reflects (1) a specific tendency to appropriate the actions of other agents, (2) a general confusion of sources with overlapping features, or (3) whether it is a confound induced by the complex structure of the conventionally used experimental paradigm. We conducted two online experiments to assess these potential contributions to observation inflation. Crucially, administering a full source monitoring test revealed a symmetrical pattern: Recognising other's actions as one's own occurred at the same rate as misattributing one's own actions to another agent. The findings resonate with source-monitoring frameworks by suggesting that source attribution errors arise due to the similarity of the sources, whereas the evidence speaks against a special status for appropriating observed actions.