How much do you trust eyewitness testimony?https://t.co/DbsrZEmrY1
— Jury Analyst (@JuryAnalyst) April 1, 2022
This is the first in a series of posts about memories of eyewitness testimony. This post describes how memories are formed and remembered, while future posts will talk about how memories decay and can be distorted and manipulated, and provide some suggestions on how to maximize the amount and accuracy of information an eyewitness provides.
John Dean was the former counsel to President Richard Nixon and the star witness for the “Watergate” Senate Committee in June 1973. His testimony played a major role in the downfall of the Nixon administration and he earned the moniker “the human tape recorder,” given his apparent ability for recalling details from dozens of conversations over many months. Not long after Dean’s testimony, the Senate committee discovered that all conversations in the Oval Office had been secretly recorded – that there was a real tape recorder in the room. As a result of the tapes vindicating Dean’s testimony, senior members of the White House staff went to prison and President Nixon was forced to resign. Once transcripts of the testimony and the tapes were released, however, it became apparent that Dean was not a human tape recorder: while he was fundamentally correct about the existence of a cover-up, his memory for even recalling the ‘gist’ of conversations was poor. This begs the question, can eyewitness testimony be trusted?
To answer this, we first need to know how memories are made and recalled. Prominent models of memory split it into two concepts: short-term memory and long-term memory. Short-term memory can be thought of as a gateway to long-term memory – it has a small capacity, and incoming information needs to be rehearsed for it to be successfully encoded into long-term memory. If information is not rehearsed (or there is too much information to rehearse) within a timeframe of a few seconds, then it is less likely to be encoded successfully into long-term memory. As an example, think about how easy it is to remember a shortlist of three random digits in comparison to trying to remember a long list of twelve random digits: with the long list, there isn’t enough space in short-term memory to successfully encode all the digits.
Long-term memory, conversely, has an almost limitless capacity. Older theories of long-term memory split into semantic memory and episodic memory. Semantic memory refers to an individual’s accumulated knowledge of facts, word meanings, and general knowledge. Episodic memory refers to specific autobiographical episodes of one’s life – this is the form of memory that was thought to be in play for Dean’s testimony, as he was recalling several separate events of which he was an active participant. Yet, it was found that the recorded conversations did not match the testimony. Dean had a tendency to remember his role as more important than it was in reality, and his memory of the gist of conversations was generally inaccurate, let alone recalling verbatim quotes (although admittedly Dean did frequently admit he couldn’t recall direct quotes during his testimony).
At this point, we (through the example of the human and real tape recorders) know that memory isn’t perfect, and is often very far from it. As a result of this case study, psychologists have reframed memory, not as a tape recorder, but rather a series of representations of what we think happened. That is, if several people are in a room for a meeting – like Dean was in many cases – each person is going to have different memories of that meeting. These representations are imperfect and incomplete. However, importantly, their accuracy can be improved through rehearsal and repetition. To take a specific example from Dean’s case, he spoke extensively and in great detail about a meeting he had with President Nixon on March 21, 1973, to clearly explain to the President that several individuals were engaging in obstruction of justice to protect the Nixon administration from the Watergate scandal. When giving testimony on this specific meeting, Dean’s memory was quite accurate. This is likely due to the fact that Dean had prepared a report for this meeting, and had repeated it ahead of time – he had rehearsed the information enough that it was successfully encoded in memory. However, he made one glaring inaccuracy: this meeting he was recalling details from had actually taken place eight days earlier, on March 13, and not from this other important meeting with the President that occurred on March 21.
Memories are fragile and subjective at the best of times. Incoming information needs to be rehearsed in order to be successfully encoded in long-term memory, but even then, the information can be distorted, as it is a representation of an event rather than a tape recorder or video camera. Fortunately, John Dean’s memory, although far from being a human tape recorder, was fairly close to the mark as it received the information it was given.
In the next post in this series, we will look at how memories decay and can be manipulated (particularly in the context of eyewitness testimony), before discussing different methods to increase the amount of information recalled by an eyewitness, as well as the accuracy of the information.
Reference: Neisser, U., 1981. John Dean’s memory: A case study. Cognition, 9(1), pp.1-22.