Consider the following evolutionary story. If a hunter on the savanna approached a watering hole, being able to remember that there had been a lion attack at that hole could be a lifesaver. But retrieving the source of the memory (did my cousin tell me about it? or was it my brother?) was less critical. As a result, our brain’s systems for source memory are not robust and are prone to failure.
This year’s Oscar nominees for best picture include four films based on true stories and each one has been criticized for factual inaccuracy. You might think: Does it really matter? Can’t we keep the film world separate from the real world? Unfortunately, the answer is no. Our minds are well equipped to remember things that we see or hear but not to remember the source of those memories.