Subjectively, memory feels like a camera that faithfully records and replays details of our past. In fact, memory is a reconstructive process prone to systematic biases and errors—reliable at times, and unreliable at others. Memories are a combination of new and old knowledge, personal beliefs, and one's own and others' expectations. We blend these ingredients in forming a past that conforms to one's haphazardly accurate view of oneself and the world.

Reconstructing the Past

Traditionally, psychologists were interested in the temporal retention of information. Since the early 1930s, many psychologists have shifted their focus from the quantity of memory to its accuracy (Koriat, Goldsmith, and Pansky, 2000). The British psychologist Frederic C. Bartlett (1932) conducted one of the first systematic investigations of memory accuracy. He asked subjects to read a legend about Indian hunters called "The War of the Ghosts" and then to retell it to another...