Eyewitnesses: how accurately do people recall events?

As a writer you rely, directly or indirectly, on recollection of events.  For many years, psychologists have been studied how well (or badly) people can remember experiences that they witness.  

In particular, the question of whether an eyewitness can give an accurate report in a courtroom has been studied.  In Europe at the start of the 20th century there was even a journal devoted to the issue.  One of the best known contributors was Hugo Münsterberg, a German Psychologist who recounts an experiment conducted by a colleague, in which one student apparently shot another in a lecture theatre.  In fact the incident was staged, and the witnesses were given a memory test afterwards.  The smallest number of mistakes stood at 26%, and the largest was 80%.

Münsterberg's work was devoted to the many applications of Psychology to everyday life, including business, education, medicine and law.  In his 1908 book 'On the Witness Stand' he begins by listing numerous errors in his own recollection of a burglary.  His report to the police turned out to be wrong in many respects, and he found it hard to know why:

"How did all those mistakes occur? I have no right to excuse myself on the plea of a bad memory. During the last eighteen years I have delivered about three thousand university lectures. For those three thousand coherent addresses I had not once a single written or printed line or any notes whatever on the platform; and yet there has never been a moment when I have had to stop for a name or for the connection of the thought..."

Münsterberg, who moved from Germany to the USA at the invitation of William James, eminent psychologist and brother of novelist Henry James, believed that the errors originate in the fast and inaccurate associations we make as we perceive the event: "The sources of error begin, of course, before the recollection sets in. The observation itself may be defective and illusory; wrong associations... may make it imperfect."  This puts me in mind of Blink - Gladwell's (2005) book on the fast, largely unconscious parts of processing which are highly adaptive - often quicker and better than conscious thought, but which sometimes, due to stress or stereotypes, can get things very wrong!

Much better known nowadays is the work of American psychologist Elizabeth Loftus.  Loftus has shown that misremembering of eyewitness accounts is commonplace, and as well as our stereotypes, it can also be influence by information received after the event - for example, police questioning.  Amazingly, the work of Loftus and colleagues has even shown that completely fictional 'memories' can be created by repeated questioning (Ceci et al, 1994).

All of which show that what we remember, or what other people who we interview remember, might be a lot less reliable than we like to think.

References
Ceci, S.J., Loftus, E.J., Leichman, M.D. and Bruck, M. (1994). The possible role of source misattribution in the creation of false beliefs among preschoolers. International Journal of Clinical & Experimental Hypnosis, 42, 304-320.
Gladwell, M. (2005).  Blink: The Power of Thinking Without Thinking.  New York: Little, Brown.
Münsterberg, H. (1908).  On the Witness Stand:  Essays on Psychology and Crime.  New York: Doubleday.

Writing, and the boundaries of memory

Whether it's a fiction writer using their life experiences as material, a biographer relying on recall of facts, or a poet noting an interesting nugget for use in a later work, memory is essential for any writer.  And yet, we know from research that for all its wonders, human memory is both limited and fallible.

One author sees the memory as a resource to be nurtured:

"By actively exploring your memory, asking imaginative questions of 'what really happened' and maybe doing some research, you will be tending to the soil, helping your memories to reveal themselves."

(Neale, 1993: 328)

Memory is major current research area in Psychology, although some basic facts were established over a hundred years ago: we have a short-term/immediate memory and a long-term memory, the short-term memory can only contain around seven items at a time (see Jacobs, 1887).  More recently, experts have tended to dismiss the simplistic idea that memory is the mind's storage area, instead viewing it as an active and flexible system.  A good example is Baddeley and Hitch's (1974) 'working memory' model.

According to the model, working memory is the part of our mind that we use for day-to-day processing, tasks and problem solving.  It is how you remember information while you are working on it.  It can achieve more than one task at once under the supervision of a processor called the central executive, which has a limited capacity, and is necessary for creative and non-routine processes.  When you divide your attention between tasks, or decide on which task to do, this is the central executive at work.  It controls the other parts, which are known as 'slave systems':

Sound and language are mainly processed in a slave system called the phonological loop, while the visuo-spatial sketchpad does routine visual processing. It is sometimes nicknamed the 'inner eye'.

Recently, researchers have suggested that there is a third slave system, the episodic buffer.  This is responsible for temporary integration of short-term processing with long-term memory storage, helping our experiences to form a coherent whole.  It helps to combine different types of information into discrete events, and also provides a link to LTM.

It will be interesting to see how research into the episodic buffer progresses, as it seems to be a key component of any task which involves recalling and making sense of past memories in a new context - a key process in any writing.

Baddeley, A.D. and Hitch, G. (1974). Working memory. In Bower, G.H. (Ed.) The Psychology of Learning and Motivation, Vol 8. London: Academic Press.
Neale, D. (2006).  Using memory.  In Anderson, L. (Ed). Creative Writing: A Workbook with Readings.  Milton Keynes: Routledge.

Jacobs (1887)

An early study of STM capacity

Even people who haven't studied Psychology can probably tell you about the 'magical number' 7 (plus or minus two) - the supposed maximum number of items we can hold in our short-term memories.

The best known study is Miller (1956), who tried to investigate the reason for the limit, finding that it was not limited to information load - the rationale being that a short word contains a lot more information than a binary digit (0 or 1) but yet the limit is still in the range of 5-9 items.

However the concept was known long before Miller, so it is not strictly accurate to attribute it to him.  Ebbinghaus investigated it, and in the UK, Jacobs studied what he called 'prehension'.  Participants were presented sequences of numbers, and asked to repeat them in the correct order. The sequences are initially short, and gradually increase in length one digit at a time. A person's digit span is the point at which they can recall sequences of a certain length (e.g. seven items) correctly 50% of the time. Jacobs found a digit span of 9.3 on average - when letters were used, the average was 7.3 items. Age differences were also found, with digit span increasing through childhood.

Miller was the first to talk about 'chunks' of information, but even that concept has largely been superceded by the idea of a time-limit (how many items can be pronounced in just under two seconds), leading Schweickert & Boruff (1986) to wittily question, magic number or magic spell?

Jacobs, J. (1887). Experiments in prehension. Mind, 12, 75-79.