Remembering kith and kin is underpinned by rapid memory updating: implications for exemplar theory.

The formation of stable social attachments requires that the specific physical characteristics of kith and kin are rapidly encoded, and that the resulting memories are updated when these characteristics gradually change. The idea that memories are updated in this way contrasts with influential exemplar models of memory, wherein each new pattern of characteristics should establish a new memory. Here, two experiments demonstrate a rapid form of memory updating in human face processing: An updated memory of a set of images of faces, varying in identity or age, is more likely to develop when these images from part of a gradually changing, rather than an abruptly changing, sequence or stream. These findings, while inconsistent with some exemplar theories, provide both a compelling demonstration of memory updating and insights into the nature of this process. They also represent a fresh impetus for theories wherein memory involves a process of evolution as opposed to mere replication of exemplars.