At the recent briefing In January 2014, Herbert Smith Freehills held a breakfast briefing entitled Total Recall or True Lies? Risks and rules to remember when interviewing, which examined what cognitive psychology can tell us about (1) the weaknesses in witness testimony, (2) biases in decision-making among lawyers and others, and (3) practical solutions for overcoming the problems examined. The briefing was delivered by Gareth Thomas (Head of Commercial Litigation, Hong Kong), Richard Norridge (Head of Private Wealth, Asia), and Ula Cartwright-Finch (Associate, Arbitration) who holds a PhD in cognitive neuroscience. Due to over-subscription, the session was repeated in February 2014.

1. The Fragility of Memory

In considering the potential (un)reliability of witnesses, academic researchers have conducted a range of studies to understand how people’s memories can be manipulated or distorted by extraneous factors. Pertinent issues include:

  • Misinformation Effect: Phrasing questions in a particular way has been observed to unconsciously change the answer that he or she would otherwise have given. A notable experiment in the field involved showing participants video clips of a road traffic accident and asking them to estimate the speed of the car at the moment of impact. By varying the verb used to describe the impact (such as ‘smashed’ or ‘hit’) researchers were able to affect the estimates given.
  • Implanted Memories: Through the use of repeated suggestion (including fabricated marketing materials) researchers have been able to convince participants in studies that they had experienced events which could not possibly have occurred.
  • Misdirected Attention: When a witness’ attention is directed towards a particular feature of a scene, they may not consciously process the occurrence of a separate feature (which they have nevertheless have observed). A well-known example of this is the famous ‘invisible gorilla’ video clip experiment. In this experiment, many participants fail to notice a person in a gorilla outfit walking through a group of individuals passing a basketball.

2. Biases in Decision-Making

In the second part of the presentation, there was a discussion of ‘biases’ identified in behavioural economics literature which can cause people to make sub-optimal decisions. In particular, these include the following:

  • Anchoring: When a person is asked to estimate a value across a range (such as the value of property), anchoring theory suggests that the answer can be manipulated up or down by providing the person with an entirely irrelevant piece of information. This has implications for the legal context. For example, in one experiment judges were effectively ‘anchored’ when being asked to value a hypothetical claim.
  • Confirmation bias: This behavioural bias is known to cause people to seek out evidence which confirms their initial hypothesis, and to disregard or rationalise opposing evidence. This has potential application in the legal context once a case theory has been formed or a particular line of argument has been accepted internally.
  • Hindsight bias: Hindsight bias represents our tendency to treat an outcome as having been the inevitable result of an action (or omission). This has been demonstrated in a study which looked at how people view an event as negligent (or not) depending on whether they evaluate a decision before or after they are told about the outcome.

3. Conclusions

A key conclusion relating to witness credibility is the importance of document retention so as to have another (potentially more credible) source of information in addition to a witness’ memory. It is also important to interview witnesses as soon as possible after the relevant event occurs, and to do so using open questions and objective terminology, so as to minimise the risk of the witness being influenced by the pre-conceptions of the interviewer or third parties.

Cognitive interviewing has become increasingly popular over the past few years as a tool to overcome some of these issues. In particular, it employs four so-called “memory retrieval rules”:

  1. Mentally reinstate the environmental and personal contexts: This involves trying to get the witness – so far as possible – to mentally revisit the event about which they are being asked. Sometimes this process can be very detailed and go into areas such as feelings and emotions on the day.
  2. Report every detail: Interviewees are encouraged to remember every detail of the incident they are recalling, even if they appear trivial e.g. even down to the colour of the carpet and the wallpaper.
  3. Describe the event in several orders: For example, witnesses may be encouraged to work backwards from the end to the beginning.
  4. Reporting from different perspectives: The witness is encouraged to say what they believe other witnesses may have seen.

With regard to behavioural biases, in-house and external counsel would be well advised to be aware of the risk of ‘anchoring’ witnesses, particularly when asking a witness to estimate a value (e.g. the number of people at a meeting or the number of times a topic was discussed). Secondly, in negligence cases, it is important to bear in mind that hindsight bias could operate against defendants, as their actions may be judged with the benefit of hindsight. Finally, there are steps that can be taken to insulate counsel from confirmation bias, such as obtaining an opinion from independent counsel or by arranging for a peer review of an investigation report or litigation strategy by a person who is not on the team directly handling the matter.