The more a trial is based on live witness testimony, the more it is an exercise in assessing (and sometimes only guessing) whether memory equals fact.  What has been written about eyewitness identification  testimony – that “ in light of the malleable nature of memory, the effectiveness of scrutinising identification evidence at trial is dependent on the extent to which past events can be accurately recounted by various witnesses” (Roberts, “The Problem of Mistaken Identification: Some Observations on Process,” IJEP 8 2 (100), April 1, 2004) – is true of all witness testimony about past events.  In every case, the question must be asked – “which past events can be accurately recounted by…witnesses[?]”


This means that trial lawyers must be memory science students.  Below are some of the lessons trial lawyers need, all taken from Professor Julia  Shaw’s THE MEMORY ILLUSION: REMEMBERING, FORGETTING, AND THE SCIENCE OF FALSE MEMORY (Random House, London, 2016).


A person’s memory of an event will retain more details if there is some emotional arousal at the time of observation, but if emotional arousal is too great memory performance drops off.  Performance looks like this:

But the arousal curve is not enough to understand memory performance.  As arousal increases, detail focus narrows so that – in Shaw’s terms – “[w]e become better at remembering critical information about the [arousing incident]…but we often become worse at remembering contextual  information.”   Lawyers must determine arousal level at time of observation and then be able to assess claims of detail recall and show factfinders why and how those claims may be exaggerated.


This is a simple, and evolutionary phenomenon in our brains.  We are bombarded with information and selectively filter out what we need, based on environment and experience.  Need proof of this phenomenon?  Test your ability to focus at focus test video


It is not bad enough that myths about memory – that there are “flashbulb” events seared into our brains or that the mind works like a video camera – persist.  There is a general belief that we as individuals can do the task of remembering well and that we “seem to systematically under-predict how much we will forget.”  The problem here is two-fold – the witness claiming memory accuracy, and the factfinder’s assessment of the same.


What may be a positive factor in assessing memory reliability is that the average age at which we can “form memories that last into adulthood is 3.5 years…”  What remains of concern is suggestibility – the younger the subject, the greater the risk of altering memory (or falsifying it) by suggestive questioning.

Shaw’s book is filled with even more, and focused, lessons on memory.  It is clear that she is an advocate for those who challenge memory reliability, particularly in court proceedings.  But her book is filled with study upon study to document how fragile memory is – and for those who litigate to ‘prove’ past events, memory knowledge is key.