Human memory does not operate like a camera or video recorder that records experiences and plays them back exactly as they happened. Memory is a constructive process that is influenced by our expectations, beliefs, and past experiences. Scientists have learned a lot about the nature of memory by studying errors and distortions that occur when people remember past experiences.

Memory is not an exact reproduction of past experiences, but instead is a constructive process that is prone to errors and distortions. In a book titled The Seven Sins of Memory: How the Mind Forgets and Remembers , Daniel Schacter proposed that memory errors could be classified into seven basic categories or “sins”. Three sins of omission refer to different kinds of forgetting: transience (loss of information over time), absent-mindedness (failures to pay attention that impair memory), and blocking (inability to retrieve information that is available in memory). Four sins of commission refer to cases in which memory is present but either wrong or unwanted: misattribution (attributing a memory to the incorrect source), suggestibility (misinformation that corrupts memory), bias (current knowledge and beliefs that distort memory for past events), and persistence (intrusive recollections of upsetting or traumatic experiences).

 As discussed at length in The Seven Sins of Memory, each of the seven sins can have negative effects in everyday life, ranging from forgetting names and appointments, to inaccurate identification of eyewitness in the courtroom, and to psychologically damaging recollections of traumas. However, studying the seven sins has provided scientists with insights into the working of memory. One of the important lessons is that despite their negative consequences in everyday life, the seven sins do not indicate that memory is a fundamentally flawed system.

Rather, the seven sins are by-products of otherwise adaptive aspects of memory that help it to function well much of the time. For example, although persistence results in disturbing intrusive memories, this is a price that we pay for a memory system that gives high priority to remembering dangerous events that threaten our survival, and that we need to remember well in order to avoid future danger. In The Seven Sins of Memory, Schacter elaborates on this idea and its implications for understanding the nature of memory.

For additional sources of scientific information about the seven sins and other aspects of memory, check out the publications page of the Schacter Memory Lab:

For videos on memory errors and distortions, see:

7 Sins of Memory – Epic Science #28

Elizabeth Loftus, How Reliable is Your Memory?

Daniel Schacter, The Seven Sins of Memory: An Update