Skip to content
Skip to main content
Author: Sarah Lloyd

The jury: Why we need to learn more about their collective decision-making processes.

Updated Wednesday, 26 July 2023
Sarah Lloyd's article discusses why it is important to know more about jury decision-making processes, and also to look at the jury as a group rather than

Find out more about The Open University's Law courses and qualifications.

This content is part of our Jury Hub.


Although juries have been studied extensively, the majority of studies have looked at extra-legal factors such as attractiveness, confidence, and pre-trial publicity (for a review see Devine & Caughlin, 2014). The actual decision making of the jury has received less attention and as a result, little is known about how juries make and reach a verdict decision (Gastil, Burkhalter, & Black, 2007; Salerno & Diamond, 2010). This blog discusses why it is important to not only know more about these decision-making processes, but also to look at the jury as a group rather than individuals.

How does the jury work in England and Wales?

In England and Wales, juries are made up of 12 people randomly selected from the electoral roll. There are various inclusion and exclusion criteria, for example, to do jury service you must be between 18 and 75, and you cannot be on a jury if you are in prison or detained under the Mental Health Act 1983 (The Juries Act, 1974). Additionally, a jury is not used in every criminal case but they are used in the most serious of cases when a defendant enters a plea of not guilty, e.g. murder (Gordon, 2015).

The idea behind using juries is that an accused person is tried by a representative sample of their peers and therefore they receive a fair trial (Willmott et al., 2017). Generally, juries are viewed postively by the public and professionals working within the criminal justice system (CJS). Research has repeatedly showed support for jury trials for example, Roberts & Hough (2009) asked participants to rate the importance of six democratic rights. They found that the right to a jury trial was rated as the most important, outweighing the right to privacy.

What are the roles and responsibilities of the jury, and what issues stem from these?

Although members of the jury have several responsibilities including the assessment of evidence, and witnesses (Curley et al., 2022), their main role is to decide a defendant’s guilt or innocence based solely and objectively on the evidence presented during the trial. This not only places a great deal of pressure on jurors, it also leads to the question of how realistic this is. The jury is a unique decision-making group. Members of the public come to jury service as a group of strangers, most with little to no experience of the CJS. They have different life experiences, beliefs, attitudes etc. All of these factors effect how they understand and interpret this evidence. In additon, research has consistently shown that jurors have difficulty understanding evidence, particularly forensic evidence (Wilcox, 2018). Another factor is that jurors initially listen to the evidence as individuals, but then come together to make the verdict decision as a group (Sprain & Gastil, 2017). This may mean they are subject to group influences and dynamics, or may not even express their views, or even discuss the important aspects of the evidence. It is therefore important the juries are examined as a collective decision making group.

Jury decision making is also impacted by restrictions imposed by s.8 of the Contempt of Court Act, 1981. This Act prevents jurors from discussing the case and their deliberations outside of the jury room. The Act also prevents researchers from studying real, deliberating juries in England and Wales. This means jury decision making processes are shrouded in secrecy (Salerno & Diamond, 2010). This is important as it could mean decision making is flawed,or ill informed and could lead to miscarriages of justice (Gastil, Burkhalter, & Black, 2007).


A problem with jury research is that the majority of studies have examined the jury as individuals rather than a collective decision making group. This is largely due to the difficulties involved in group and jury research. Mock juries tend to be used as real juries are not viable. There are also methodological issues with existing research such as using small samples, e.g. a jury of 6; not using real cases, a trial, or any type of deliberation (Devine, Clayton., & Dunford, 2001). This means that few studies have examined the jury in a realistic setting as possible, so little is known about how they reach a verdict.

My PhD research aims to redress this deficit in research by exploring the group decision making processes of the jury and replicating trial conditions as realistically as possible. My research used two mock juries, who listened to a trial based on a real case, and then deliberated in a ‘jury room’ until they reached a verdict. I am interested not only in what they talked about, or felt was important to their decision, but also the group dynamics and the effect this has on the group’s decision making processes. The hope of this research is to pave the way for further studies to see if themes are common, and to improve the outcomes of jury decision making more generally using real juries. This is important as if reflective of real juries, it suggests their decision making is characterised by errors, lack of deep discussion, and group influence.

Arguably then, juries should be examined as a group since they reach the verdict that way. By finding out more about these decision making processes we can ensure a fairer system, not only for the defendant and victim, but for their families and the wider community. This may also improve how the CJS is viewed and trusted by the public. More informed decision making means that issues and difficulties can be identified within the process, and can lead to more realistic expectations of juries.


Clay, D. (2017). The effects of perceived authority on the decision-making processes of mock jurors. Social Science Research Network, 1-37. doi: 10.2138/SSRN.2966759.


Curley, L., Munro, J., & Dror, I. (2022). Cognitive and human factors in legal layperson decision making: Sources of bias in juror decision making.  Medicine, Science & the Law. Doi: 10.1177/0258024221080655.


Devine, D., & Caughlin, D. E. (2014). Do they matter? A meta-analytic investigation of individual characteristics and guilt judgments. Psychology, Public Policy, and Law, 20, 109-134. doi: 10.1037/law0000006.


Devine, D., Clayton, L.D., & Dunford, B, B. (2001). Jury decision making: 45 years of empirical research on deliberating gorups. Psychology, Public Policy, and Law 7(3), 622-727. Doi: 10.1037/1076-8971.7.3.622


Gastil, J., Burkhalter, S.,  and Black, L. (2007). Do juries deliberate? A study of deliberation, individual difference, and a Municipal Courthouse. Small Group Research, 38(3). Doi: 10/1177/1046496407301967


Roberts, J. V., & Hough, M. (2009). Public opinion and the jury: An international literature review. MOJ reseach series 1/09 February 2009.


Salerno, J. M., & Diamond, S. S. (2010). The promise of a cognitive perspective on jury deliberation. Psychonomic Bulletin & Review, 17(2), 174-170. Doi: 10.3758/PBR.17.2.174


Sprain, L., & Black, L. W. (2017). Deliberative moments: Understanding deliberation as an interactional accomplishment. Western Journal of Communication, 82(1), 1-29. Doi: 10.1080/10570314.2017.1347275


Wilcox, A., & NikDaeid, N. (2018).  Juror’s perceptions of forensic science expert witnesses. Forensic Science International. Doi: 10.1016/j.forsciint.2018.07.030.


Willmott, D., Boduszek, D., & Booth, N. (2017). The English jury on trial. Willmott, Dominic, Daniel Boduszek, and Nigel Booth. 2017. “The English Jury on Trial”. Loughborough University.


Become an OU student


Ratings & Comments

Share this free course

Copyright information

Skip Rate and Review

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?