Witnesses: Remember it like it was yesterday?

On 22 November 1963 I know exactly where I was and what I was up to at 6.00pm. Honest. Put me in a witness box, on oath, and I would swear until I was blue in the face that I know. But Mr Justice Leggatt has his doubts. Not that we knew each other when he was about three years old. No, it’s that in his daytime job now, he has a particular interest in whether your memory and the evidence you give can be relied on by him or any tribunal. He wrote a mini essay in a recent judgment, Gestmin SGPS S.A. vs Credit Suisse (UK) Limited, about how unreliable your memory is, and since every day adjudicators and arbitrators and judges are reading witness statements telling us with absolute conviction who did what on site and when and why the other bloke is a scoundrel and that the other bloke can’t be believed; well then, what’s the judge on about?

There are he says, important lessons from a century of research into memory that most of us seem to be unaware of. Two common errors stand out: first, it is a truth that the stronger and more vivid our feeling or experience of recollection, the more we believe it is accurate; second, the more confident a person is in their recollection, the more we are likely to believe it. But the research shows these notions to be errors. A mental record, which is fixed at the time of experience of an event, fades more or less slowly over time. The psychological research has demonstrated that your memory is fluid and malleable, being constantly re-written whenever the so-called memory is retrieved. This, says the judge, is true even of a particularly shocking or traumatic event. Apparently external information can intrude into a witness’s memory, as can his or her own thoughts and beliefs, which can cause dramatic changes in recollection. Go further, and events can come to be recalled as memories which did not happen at all, or which happened to someone else.

Events can come to be recalled as memories which did not happen at all, or which happened to someone else

Just think about all this. The stock in trade of any dispute decider is weighing up facts, the evidence plonked in front of him, or what is tumbling out of your mouth as a witness. And the judge is digging me in the ribs, warning me to watch out. He blinks about how unreliable things become when recalling past beliefs. You know the sort of past beliefs that we have to cope with … about why the work was delayed, why the delay was critical, why the consequences are obvious. But the memory is up to its tricks. Memories of past beliefs are revised to make them more consistent with our present beliefs, and the previous claim about the extension of time shifts when new suggestions about an event are planted, and damn it you are convinced!

And now Mr Justice Leggett gets into his stride. He tells us, and I believe him, that the process of civil litigation itself, such as construction disputes, subjects the memories of witnesses to powerful biases. You have a stake or loyalty in the dispute. Allegiances are created. A team is created to win in court. He says “considerable interference with memory is introduced by the procedure of preparing for trial”. That written witness statement is usually drafted many moons after the event by refreshing the memory by reading the old correspondence, and those statements “go through several iterations before being finalised”. And by the time of a hearing, that person will have read and re-read his statements and whether true or false the memory becomes increasingly based on that material.

Come to a time of cross examination, it is not uncommon for the witness to be asked if his written statement is a genuine recollection or instead a reconstruction of events. Of course it is a reconstruction, and no matter the appearance of vividness and apparent authenticity of memories, “not a reliable measure of the truth”.

So? Well, says Mr Justice Leggett: “In the light of these considerations, the best approach for a judge to adopt in the trial of a commercial case is, in my view, to place little, if any, reliance at all on witnesses’ recollections of what was said in meetings and conversations, and to base factual findings on inferences drawn from documentary evidence and known or probable facts.

“This does not mean that oral testimony serves no useful purpose - though its utility is often disproportionate to its length. But its value lies largely in the opportunity which cross-examination affords to subject the documentary record to critical scrutiny and to gauge the personality, motivations and working practices of a witness, rather than in testimony of what the witness recalls of particular conversations and events. Above all, it is important to avoid the fallacy of supposing that, because a witness has confidence in his or her recollection and is honest, evidence based on that recollection provides any reliable guide to the truth.”

So, what was I doing on that day in November 1963? Whatever it was, I don’t believe me.

Tony Bingham is a barrister and arbitrator at 3 Paper Buildings, Temple