The Effect of Imagined Time-Distance on Imagination Inflation for Children and Adults

Abstract

Imagining fictitious events from one's childhood has consistently resulted in an increase in confidence that they occurred, a phenomenon known as imagination inflation (Garry, Manning, Loftus & Sherman, 1996; Manning, Garry, Assefi & Loftus, unpublished manuscript). However, the research so far has failed to find the primary mechanism driving imagination inflation. Both source confusion, a failure to attribute the correct source of a memory, and increased familiarity, an increase in the degree to which an event seems familiar, are supported by recent research. To discriminate between these two mechanisms, two experiments manipulated the time-distance of the imagined events: Subjects were asked to imagine fictitious events occurring to them in the distant past or in the recent past. Both children and adults acted as subjects. Relative to controls, both adult and child subjects increased their confidence that a fictitious event had occurred after imagining the event in the distant past. No imagination inflation was found in the recent condition for either children or adults. These results are consistent with a source confusion explanation. However, the difficulties involved in separating familiarity and source confusion are pointed out. Implications of imagination inflation in both eyewitness and therapeutic arenas are discussed.