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What can Experts and Judges Learn From Cognitive Psychology? Are we Biased and, if so, How?

Medico Legal

by Koch H, Cosway R, De Haro L & Kon T


Legal psychology (LP) involves the application of empirical, psychological understanding and research to the law, legal institutions and law-centred professionals. LP applies to many areas of civil litigation such as expert, counsel and judicial decision-making, interviewing and evidence gathering, inter-professional and claimant – professional communication. Together, legal psychology and forensic psychology form the field more generally recognised as ‘Psychology and Law’ (1).

The main process steps of civil litigation and the involvement of expert witnesses, barristers and judges are linked to the several main branches of psychology (figure 1 overleaf), and their effects on the behaviour of both judges and expert witnesses.

The interface between psychology and civil law has been discussed and illustrated in terms of communication/ social psychology (2) and conflict resolution psychology (3). The interface between medico-legal case reporting and commentary and clinical opinion (4) has also been noted.

This paper continues the theme of these previous publications by discussing the crucial importance of cognitive psychology, decision making and bias to the impartial and robust delivery of opinion and justice in civil claims.

Judges, Experts and Civil Justice.

For the purposes of this article, Judges and Experts are both highly trained professionals who are faced on a daily basis with complex evidence and decisions. There is a paucity of UK & USA research on judicial or expert decision-making behaviour. Both are being encouraged to be more actively involved in either case management (judges) or complex evidence scrutiny (experts). The changing nature of these roles require a re-think of how information and research such as Law and Psychology can interface. Some information is available on decision making in appellate courts (5) and in written decisions, dealing with concepts such as neutrality of the senior judiciary (6). The literature indicates little about how judicial and expert work and decision making occurs, how they manage uncertainty and contribute to justice. The business of judging (7) and of providing expert opinion (8) is complex and it is essential that thinking processes and the effects of cognitive bias are well understood and managed.

Cognitive and legal psychology: Appropriate bed fellows?

Cognitive psychology (CP) is the study of thinking, language, perception and problem solving. The main focus is on the way we think and how this affects our behaviour. We know that when we listen, think or ‘attend’ to information we do this in a selective or divided way, focusing on some messages more than others. Concepts like the ‘cocktail party effect’ and ‘Gestalt’ effects are relevant here i.e. the ability to attend to one thought or conversation in the face of many others. Dealing with quantities of information relies on memory which has a variety of facets (semantic, accessibility, levels of meaning, temporal). Perception and interpretation of stimuli both physical and psychological affect our behaviours.

As a result, those interested in how decision-making is informed by cognitive psychology, consider meta cognition or “the thoughts we have about our thoughts”. This involves positive monitoring our own thinking and behaviour and understanding how to apply specific cognitive strategies to arrive at robust decisions. We know that professionals develop schemata which leads them to consistently react in either a positive or a dysfunctional manner.

Logical paradox and seeking quality opinion.

Experts, barristers and judges are frequently confused by apparent paradoxes in evidence which significantly shape their opinions. These professionals may not always be aware of these paradoxical situations and logical incoherence (9). Unless one is able to recognise and manage these logical dilemmas, it is inevitable that the quality and robustness of opinions will be inevitably compromised. Such logical errors are the subject of this paper based as they are in cognitive psychology and its emphasis on bias, dilemmas, traps and snags. It is difficult to apply high level reasoning to evidence but a starting point is to be able to analyse logical rules from a cognitive psychology perspective.

Dilemmas and Paradoxes in Differential Diagnosis.

Clinicians, of any profession, understand that when faced with ambiguous claimant data they must consider a range of opinion and help the court understand the logical reasoning behind their diagnostic findings. Equally, the concepts behind symptom duration, severity, and, ultimately, veracity and reliability compound this clinical paradox. Clinical and legal professionals carefully analyse arguments for logical consistency (10).

Am I biased?

Cognitive biases are tendencies to think in certain ways that can lead to systematic deviations from rational judgment. There are approximately 200 types of cognitive bias that can affect our opinion-forming and decision making. Figure 2 below shows common examples of these.

Fig 2 - Common examples of cognitive bias:

Anchoring: The tendency to rely too heavily on one piece of information.

Bias blind spot: The tendency to see oneself as less biased than other people.

Confirmation Bias: The tendency to search for, focus on and remember information that confirms one’s preconceptions.

Fundamental Attribution Error: The tendency to over-emphasise personality-based explanations for behaviour observed in others while under-emphasising the role and power of situational influences.

Projection Bias: The tendency to overestimate how much our future selves/behaviour will stem from one’s current thoughts and values, thus leading to sub-optimal or less accurate choices or decisions.

The common underlying causes of cognitive biases are a limited rationality, low costs of being biased/wrong, and/or cognitive dissonance (aiming for a consistent, explanatory belief). Professionals display certain traits in their susceptibility to decisionmaking biases such as over-confidence and bias blind spot (unawareness).

Problem solving in a legal context.

Legal professionals problem solve using many different methods, sometimes in an organised manner, irrespective whether the problem is illdefined (no clear goals, paths or expected solutions) or how well the problem is defined. Both logic and problem clarification are used to understand what rules could be applied to solving a problem. The problem-solving cycle (the process of problem definition, information organisation, solution evaluation) involves techniques listed in Fig 3 below:

Fig 3 – Problem Solving Skills


Subdivision into smaller solvable problems

Hypothesis testing

Lateral thinking


Root cause analysis

Trial and error testing

Common barriers to problem solving include:

Confirmation Bias – unconscious or unintentional collecting of data in such a way that favours a preconceived notion.

Mental Self – Using techniques that one has become accustomed to rather than new, innovative or simpler methods.

Functional Fixedness – Narrow or fixed ways of thinking or solving problems.

Irrelevant Information – Having information to digest which serves no purpose in helping solve a particular problem. This makes solving relatively simple problems much harder.

Common thinking errors in legal professionals.

Cognitive distortion can be seen in all professionals working in civil justice from time to time.

These distortions are logical but not rational. They create real difficulty with thinking (11). We all occasionally make these thinking errors shown in Fig 4:

Fig 4 – Common Thinking Errors.

1. All-or-nothing thinking: Seeing things in black and white categories. A mistake means we are a total failure.

2. Overgeneralisation: A single negative event as a never-ending pattern of debt.

3. Disqualifying the positive: Positive experiences are rejected by insisting they ‘don’t count’ for some reason. A negative belief that is contradicted by everyday experiences is maintained.

4. Jumping to conclusions: A negative interpretation is made even though there are no definite facts that convincingly support this conclusion.

5. Magnification (Catastrophising) or minimisation: You exaggerate the importance of things (such as your goof-up or someone else’s achievement), or you inappropriately shrink things until they appear tiny (your own desirable qualities or other fellow’s imperfections). This is also called the binocular trick.

6. Emotional Reading: You assume that your negative emotions necessarily reflect the way things really are: “I feel it; therefore it must be true”.

7. Should Statements: You try to motivate yourself with should and shouldn’t, as if you had to be whipped and punished before you could be expected to do anything. “Musts” and “oughts” are also offenders. The emotional consequences are guilt. When you direct should statements towards others, you feel anger, frustration, and resentment.

8. Labelling and Mislabelling: This is an extreme form of overgeneralization. Instead of describing your error, you attach a negative label to yourself. “I’m a loser”. When someone else’s behaviour rubs you the wrong way, you attach a negative label to him. “He’s a goddamn louse”. Mislabelling involves describing an event with language that is highly coloured and emotionally loaded.

9.Personalisation: You see yourself as the cause of some negative external event, which in fact you were not primarily responsible for.

Reflective Practice for judges, counsel and experts.

The ability to reflect on one’s actions and engage in a process of continuous learning and intellectual improvement is crucial, and informs everyday professional practice by deliberate reflection on experience. For many professionals, this may be the most important source of personal professional development and improvement. Reflective practice (RP) provides professionals with opportunities to critically review what has been successful in the past and where improvement in practice can be made. Typical skills of RP include seeking feedback, identify daily lessons, valuing personal strengths and accomplishments, empathising, planning for and creating one’s future practice.


Many thousands of cases processed by the judiciary and by Expert Witnesses are managed and decided upon even if they never reach final adjudication in court. It has been suggested that cognitive patterns about decision making are best investigated within the everyday expert witness and judicial determination made in the lower courts rather than the analysis of reasoning in the Superior Courts (12).

Greater understanding of the reality and practice of judicial and expert witness work will result in more precise identification of what it takes to be a good judge or a good expert in terms of specific skills necessary for such complex and demanding performance (13).

Special training programmes, expert and legal supervision and increasingly validated guidelines for legal and medico-legal practice are essential (14) both for new professionals and experienced professionals needing continuing education. Research is currently underway on Expert Uncertainty (15) and a similar study involving the judiciary is planned.

More recently, it has been supported that judges be provided with ‘toolboxes’ of concise guidance to help raise their awareness of scientific topics (e.g. medical conditions, engineering premises, statistics). It is recommended that they also be provided with clear guidance on how psychological processes affect the decision making process utilised by both judges and experts.


1. Wikipedia (2017) Legal Psychology. www.wikipedia.org.

2. Koch HCH, Humphreys K, Byram V, Livingstone L, Wilson S (2017) Communication Psychology in Civil Law: The Microskills of Impartiality & Neutrality. Expert Witness Journal. 14.10.17.

3. Koch HCH (2017) Conflict Resolution Psychology and Civil Litigation. PIBULJ. November.

4. Koch HCH (2016) Medico-legal Case Commentary: The Psychology of Justice: The Interface Between Psychology and Civil Law. Mathews Open Access Journals. July 2017. 1(1):005.

5. Woolf L (2008) The Pursuit of Justice. Oxford University Press.

6. Darbyshire P (2005) Darbyshire on the English Legal System. Sweet and Maxwell London.

7. Bingham Lord (2011) The Business of Judging. Oxford University Press.

8. Koch HCH (2017) Legal Mind: Contemporary Issues in Psychological Injury and Law. Expert Witness Publications. Manchester.

9. Merten T (2017) Logical Paradoxes and Paradoxical Constellations in Medico Legal Assessment. Psychol. Inj. & Law. 10,264-273.

10. Anderson JR (2015) Cognitive Psychology and its Implications. New York. Wortt Publishers.

11. Burns D (2000) Feeling Good. The New Mood Therapy Revised & Updated. Harper. London.

12. Cross FB (2007) Decision Making in the US. Courts of Appeals. Stanford University Press. California

13. Genn H (2008) Judging Civil Justice. Cambridge.

14. Young G & Brodshey SL (2016) The 4 D’s of Forensic Mental Health Assessments in Personal Injury. Psychol. Injury & Law. 9, 278-281.

15. Koch HCH, Newns K, Cosway R (2016) Managing Uncertainty in Experts: What are the key issues? Expert Witness Journal.

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For correspondence, contact lead author at

Hugh Koch Associates, Festival House,

Jessop Avenue, Cheltenham, GL50 3SH or at

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