Many recent high-profile and controversial cases have shifted public attention to jury selection, and specifically how jury selection and representation on juries impact the outcome of criminal cases. In the high-profile trial of George Zimmerman—who shot and killed Trayvon Martin, an unarmed Black teenager—media outlets devoted significant attention to the link between his acquittal and the fact that his all-woman jury contained only one nonwhite juror.1 Recently, Kyle Rittenhouse was acquitted of homicide charges after he shot and killed two men during a protest of a police shooting. Some media headlines focused on the unusual jury selection method, which resulted in a jury that contained only one person of color.2 When unpopular verdicts are delivered by juries that appear nondiverse or homogenous, the outrage about these outcomes is often amplified—as these processes violate people’s sense of justice.3 Despite several U.S. Supreme Court decisions that focus on ensuring proper representation on juries, people of color are routinely not properly represented on juries in criminal trials for a variety of reasons.4 Concerns about representation on juries has garnered the attention of behavioral researchers to explain both why people of color are excluded from serving on juries and also the psychological consequences of increasing the diversity of juries. This article discusses how psychological research provides explanations for why juries often do not contain people of color and discusses the explanations for what psychology says about the effects of jury diversity on outcomes in criminal cases.
Why Are People of Color Often Excluded from Jury Service?
Jurors who are members of racial and ethnic minority groups are underrepresented in their participation in jury service for a variety of reasons. Historically, certain groups (Black men in particular) were excluded from jury service so routinely that courts ruled explicit barring of specific demographic groups to be unconstitutional.5 Despite explicitly disallowing the exclusion of people of color from serving on juries, less explicit and obvious methods of preventing people of color from serving on juries were still in practice. These included color-coded jury selection wheels determined by race or even in-person intimidation.6 While many of these more obvious barriers are no longer in use, the present-day methods of calling jurors to jury duty invoke institutional barriers resulting in juries that underrepresent people of color. For example, relying on voter registration records when summoning jurors is a method demonstrated to reduce the rate of members of underrepresented groups on juries.7
Another barrier to participation (which psychology is better able to weigh in on) is that jurors must “survive” the process of jury selection. Because peremptory challenges do not require any reason or justification for striking jurors, this may be the primary method by which jurors who are people of color are excluded from serving on juries. The ruling in Batson v. Kentucky8 sought to eliminate the use of racially biased peremptory challenges—ultimately concluding that the practice of eliminating jurors based on their race or ethnicity was unconstitutional. Although technically either side (prosecution or defense) might remove people of color from serving on juries, research documents that prosecutors are more likely to exclude people of color from jury service than are defense attorneys.9 The Batson ruling established a two-step process for reviewing peremptory challenges. First, a defense attorney makes a prima facie case for discrimination, which is then referred to the judge.10 If the judge agrees with the defense attorney that it appears the peremptory challenge was based on race, the burden shifts to the prosecution to make a case that their dismissal was race-neutral. While this process legally prohibits the use of race-based peremptory challenges, research finds that Batson challenges rarely succeed.11
Recent Supreme Court cases reveal some of the issues with the Batson process. Foster v. Chatman12 demonstrates the difficulty of proving that peremptory challenges are based on race. The petitioner in this case—Timothy Foster—raised a Batson challenge during the trial when prosecutors dismissed all Black jurors from serving on the jury, but the judge in the original case accepted the prosecutor’s race-neutral reasons for their peremptory challenges. In the case, the prosecution highlighted and wrote the letter “B” next to each Black juror—and their notes focused on race as a major factor in striking each juror. Additionally, Black jurors were removed for reasons that were not used to strike white jurors. For example, the prosecutor struck a Black juror because of their youth, while younger white jurors remained on the jury. The Supreme Court did overturn Foster’s conviction, but years after his initial conviction—demonstrating the difficulty the defense often faces when bringing Batson challenges. In 2019, the Supreme Court overturned Curtis Flowers’s conviction based on illegal peremptory challenges.13 Flowers had six trials, and in the first four trials, prosecutors removed all (36 of 36 possible) Black jurors from serving on his juries. In the sixth trial, the prosecutors removed five out of six potential jurors who were Black. Through review, the Supreme Court also noted that the prosecution spent more time during voir dire questioning the Black potential jurors than they did the white jurors. Similar to Foster, the U.S. Supreme Court reversed the conviction for Curtis Flowers, but he was convicted at six trials before his eventual exoneration.
Psychological research can provide some insight into why Batson challenges so rarely succeed. Samuel Sommers and Michael Norton14 performed a study in which participants engaged in a mock voir dire decision-making task. Their sample of college students, law students, and attorneys viewed the profiles of two potential jurors, one of whom they would be eliminating from jury service. The jurors were described as an advertising executive and a journalist, one was described as Black and one was described as white. The profiles were switched so that for half of the participants, the journalist was Black and the advertising executive was white—and for the other half the backgrounds were reversed. Participants were significantly more likely to eliminate the Black juror, regardless of whether they were an advertising executive or a journalist. When asked to provide reasons as to why they made their decisions, participants mentioned race only 7 percent of the time, when clearly race was impacting their decisions. The Sommers and Norton study revealed that people find it easy to make race-neutral explanations for decisions. The psychological research is consistent with legal scholars’ assessment that courts rarely reject attorneys’ race-neutral reasons for peremptory challenges.15 While much research has documented the fact that jurors who are members of underrepresented groups are more likely to be struck by peremptory challenges than white jurors, Batson challenges do not appear effective in reducing discrimination against people of color and preventing them from serving on juries.16 As a result, many juries are not representative of the community in which the trial takes place, which has implications for the decisions made by juries.
Why Is Jury Diversity Important?
Ensuring proper representation on juries is important for a variety of reasons. A primary concern is that preventing people from serving on juries based on their membership in a racial/ethnic minority group violates people’s right to serve on a jury.17 Additionally, decisions made by diverse juries are more likely to be seen as fair by the public than those made by nondiverse juries.18 Psychological researchers have mostly focused on jury diversity’s impact on decision-making. A primary concern is whether increasing diversity on juries can eliminate bias against defendants who are members of racial/ethnic minority groups. In addition to preventing bias and ensuring inclusivity in jury decisions, a body of psychological research establishes that diverse juries tend to perform more careful and thorough evaluation of the evidence than nondiverse juries.
Jury Diversity Reduces Racial Bias
The assumption that decisions made by diverse juries are more fair than decisions made by nondiverse juries is primarily based on the assumption that increasing diversity reduces the prevalence of racially biased outcomes. Due to the overwhelming racial/ethnic disparities in incarceration and sentencing decisions,19 concerns about bias against people of color are a major source of motivation to increase representation on juries. A body of psychological research supports the assumption that diverse juries deliver outcomes that are less susceptible to racial bias than nondiverse juries.20 One area that supports this assumption is research examining racial bias in individual mock juror decisions. Most research examining racial bias in criminal cases uses individual mock jurors to evaluate how jurors make decisions. Individual juror decisions can shed light on how jury groups can make decisions because jury decisions tend to align with the initial majority ballot vote.21 Mock juror studies have found evidence of both racial bias and outgroup bias against defendants. Several studies suggests that mock jurors are more likely to convict and render harsher guilt judgments against defendants who are members of underrepresented racial/ethnic minority groups.22 Other studies examine mock jurors’ tendency to deliver harsher punishments for people of color, with many studies finding that defendants of color receive longer sentences and the death penalty more often than white defendants.23
Although there are persuasive reasons to believe that individual mock juror decisions resemble those made by real juries composed of multiple individuals, there are also some pivotal differences between individual and group decisions that have implications for jury decision-making.24 Individual juror judgments are often completed outside of the influence of other jurors, with no outside influence. Jury group deliberations, on the other hand, often involve an initial vote on the verdict, which may affect individual decision-making. Those who vote earlier in the process may influence the decisions of jurors who provide their verdicts later.25 Additionally, a variety of social group influences may come into play during a jury deliberation that have the potential to affect the outcome.26
Before jury diversity studies were conducted in their entirety, early research used juries that were considered “death-qualified” to approximate the effects of diversity on racial bias. Death-qualified juries were those that experienced the voir dire process for death penalty cases. This voir dire process involved ensuring that all members of the jury would be willing to sentence a defendant to death. Research on capital juries finds that so called death-qualified juries tend to contain fewer women and people of color than typical juries do.27 Consistent with predictions, death-qualified juries (with a higher proportion of white men) were more likely to discriminate against Black defendants than juries that were not death-qualified.28 More recent work examining mock capital juries examines the effects of increasing the proportion of white men on juries. Researchers manipulated the race of a defendant in a capital trial and compared death-qualified juries to non-death-qualified juries.29 When the defendant was white, the proportion of white men on the jury had no impact on the jury’s decisions. In cases where the defendant was Black, however, increasing the proportion of white males on the jury was associated with an increase in death penalty sentences. Ultimately, the research finds overwhelming support for diversity’s ability to reduce racial bias in jury decisions.
Jury Diversity Increases the Quality of Jury Decisions
Some basic group research examining the effectiveness of diverse groups can provide insight into the benefits of diversity and how it improves group decision-making. Most psychological models of diversity research use an information exchange model to determine that including varied perspectives (in the form of including people with diverse backgrounds—including most definitions of diversity) increases the amount of information a group discusses.30 Increasing the number of perspectives integrated into the group increases the amount of information absorbed by both the individuals in the group and the group as a whole—which improves the quality of that group’s discussion. In addition to discussing more information, increasing the diversity of a group tends to increase the decision-making quality of that group.31 While most of the research on group diversity tends to favor increasing diversity on juries, there is some research that warrants caution. In cases where diversity is defined by interracial groups, research on interracial interactions suggests that they can cause discomfort and anxiety, in addition to sometimes resulting in impaired performance on cognitive tasks.32 Even with the presence of some strain in terms of stress and interpersonal relationships, the overall trend of the psychological literature suggests that diverse groups exhibit enhanced performance compared to nondiverse groups.33
The benefits of diversity are supported by the psychological research studies that directly examine how diversity impacts the quality of jury decision-making. Samuel Sommers in 2006 performed a study that used mock jurors recruited from a real group of potential jurors awaiting jury duty at a courthouse. The mock jurors watched a trial video and then deliberated in either diverse or nondiverse juries. The researchers defined diverse juries as those that included Black jurors and nondiverse as juries with only white jurors. Even prior to deliberations, the white jurors were less likely to discriminate against the Black defendant if they anticipated interacting with Black jurors. Examining the content of deliberations revealed that diverse juries discussed more case facts, deliberated longer, and made fewer errors than nondiverse juries.
Recent work also explores how deliberating in diverse juries affects cognitive processes and communication. Margaret Stevenson and colleagues explored the effects of anticipating deliberation in a diverse jury and how it impacted both the thought process and the communication style of mock jurors.34 In this study, white participants were told they were deliberating in either diverse (including jurors who were people of color) or nondiverse juries. Jurors who believed they were deliberating in diverse juries engaged in more self-focus and used more self-regulating language (indicating a higher level of thinking) than did jurors deliberating in nondiverse juries. Stevenson and colleagues also found that jurors spoke less when deliberating in a diverse jury. The researchers concluded that white jurors deliberating in diverse juries engaged in more careful consideration before speaking than they did in nondiverse juries. Liana Peter-Hagene performed a similar mock jury simulation and found that jurors who deliberated in diverse juries engaged in more thorough cognitive processing than jurors deliberating in nondiverse juries.35 As a result, white jurors deliberating in diverse juries seem to engage in more thorough processing, which is consistent with higher levels of cognitive depletion following the interaction.
While research documents that white jurors deliberating in diverse juries experience cognitive benefits from the process, recent work also suggests benefits for jurors who are members of underrepresented groups. Amanda Bergold and Margaret Kovera examined the effects of diversity on the jury group deliberation process on both high- and low-status mock jurors.36 In their first study, Black and white mock jurors deliberated in diverse and nondiverse juries. Analyzing the content of the deliberations revealed that both white and Black mock jurors made higher-quality contributions to the discussion when deliberating in diverse juries, compared to when they only deliberated with members of their own racial group. In the second study, wealth and power were experimentally manipulated, and then jurors deliberated in diverse or nondiverse juries (defined by wealth and power). Consistent with the first study, jurors deliberating in diverse juries (as defined by wealth and power) made higher-quality contributions to the deliberation discussion than those deliberating in nondiverse juries.
Psychological research has a great deal to say about how ensuring greater representation on juries may result in superior outcomes in criminal trials. Much of the courts’ emphasis focuses on the reduction of racial bias against defendants who are members of racial/ethnic minority groups in jury decisions, which is largely supported by the psychological literature. Increasing the diversity of juries reduces racial bias both by including individual jurors who are less likely to exhibit racial bias and by reducing jurors’ tendency to make racially biased decisions. Decisions made by diverse juries are superior to those made by homogenous juries because they often affect the information processing of jurors deciding the case. Researchers have noted the presence of both past and current structural barriers to jury participation for people of color and individuals with low socioeconomic status. While Batson attempts to address this issue, the psychological literature explains why the Batson safeguard is inadequate as a method to prevent racially biased peremptory challenges. The psychological research demonstrating the benefits of diversity highlights the importance of addressing these inadequacies.
Justice Thurgood Marshall makes an important point in stating: “When any large and identifiable segment of the community is excluded from jury service, the effect is to remove from the jury room qualities of human nature and varieties of human experience the range of which is unknown, and perhaps unknowable.”37
Justice Marshall was likely correct in stating that excluding any cognizable groups from jury service has implications that are hard to predict. Psychological research has attempted to discover some of the “unknown” and “unknowable” consequences of unrepresentative juries, but it certainly has not explored the entire universe of disadvantages nondiverse juries present. The psychological research highlights the importance of reducing structural barriers to participation on juries and improving the degree to which juries demographically resemble the communities they seek to represent.
1. Andrew G. Ferguson, Why the George Zimmerman Trial’s All-Female Jury Is New, The Atlantic (June 21, 2013), https://www.theatlantic.com/national/archive/2013/06/why-the-george-zimmerman-trials-all-female-jury-is-news/277103.
2. David K. Li, Kyle Rittenhouse Conducts Random Draw, Seating 7 Women and 5 Men for His Jury, NBC News (Nov. 16, 2021), https://www.nbcnews.com/news/us-news/jury-7-women-5-men-picked-kyle-rittenhouse-trial-rcna5694.
3. Halford H. Fairchild & Gloria Cowan, The O. J. Simpson Trial: Challenges to Science and Society, 53 J. Soc. Issues 583 (1997).
7. Paula Hannaford-Agor & Nicole L. Waters, Safe Harbors from Fair-Cross-Section Challenges? The Practical Limitations of Measuring Representation in the Jury Pool, 8 J. Empirical Legal Stud. 762 (2011).
8. 476 U.S. 79 (1986).
9. David C. Baldus et al., The Use of Peremptory Challenges in Capital Murder Trials: A Legal and Empirical Analysis, 3 U. Pa. J. Const. L. 3 (2001); Mary R. Rose, The Peremptory Challenge Accused of Race or Gender Discrimination? Some Data from One County, 23 Law & Hum. Behav. 695 (1999).
10. Baldus et al., supra note 9; Rose, supra note 9.
11. Kenneth J. Melilli, Batson in Practice: What We Have Learned About Batson and Peremptory Challenges, 71 Notre Dame L. Rev. 447, 483–84 (1996).
12. 578 U.S. 488 (2016).
13. Flowers v. Mississippi, 139 S. Ct. 2228 (2019).
14. Samuel R. Sommers & Michael I. Norton, Race-Based Judgments, Race-Neutral Justifications: Experimental Examination of Peremptory Use and the Batson Challenge Procedure, 31 Law & Hum. Behav. 261, 266 (2007).
15. Nancy S. Marder, Batson Revisited, 97 Iowa L. Rev. 1585 (2012).
16. Melilli, supra note 11.
17. Douglas L. Colbert, Challenging the Challenge: Thirteenth Amendment as a Prohibition Against the Racial Use of Peremptory Challenges, 76 Cornell L. Rev. 1 (1990).
18. Fairchild & Cowan, supra note 3.
19. Jennifer S. Hunt, Race in the Justice System, in 2 APA Handbook of Forensic Psychology: Criminal Investigation Adjudication, and Sentencing Outcomes 125 (Brian L. Cutler & Patricia A. Zapf eds., 2015).
20. William J. Bowers, Benjamin D. Steiner & Marla Sandys, Death Sentencing in Black and White: An Empirical Analysis of the Role of Jurors’ Race and Jury Racial Composition, 3 U. Pa. J. Const. L. 171 (2001).
21. Harry Kalven Jr. & Hans Zeisel, The American Jury 58–68 (1966).
22. Russ K. K. Espinoza & Cynthia Willis-Esqueda, Defendant and Defense Attorney Characteristics and Their Effects on Juror Decision Making and Prejudice Against Mexican Americans, 14 Cultural Diversity & Ethnic Minority Psych. 364 (2008); Gordon Hodson, Hugh Hooper, John F. Dovidio & Samuel L. Gaertner, Aversive Racism in Britain: The Use of Inadmissible Evidence in Legal Decisions, 35 Eur. J. Soc. Psych. 437 (2005); Samuel Sommers & Phoebe C. Ellsworth, White Juror Bias: An Investigation of Prejudice Against Black Defendants in the American Courtroom, 7 Psych. Pub. Pol’y & L. 201 (2001); Samuel R. Sommers & Phoebe C. Ellsworth, Race in the Courtroom: Perceptions of Guilt and Dispositional Attributions, 26 Personality & Soc. Psych. Bull. 1367 (2000).
23. Andrea DeSantis & Wesley A. Kayson, Defendants’ Characteristics of Attractiveness, Race, and Sex and Sentencing Decisions, 81 Psych. Rep. 679 (1997); Robert ForsterLee, Lynne ForsterLee, Irwin A. Horowitz & Ellen King, The Effects of Defendant Race, Victim Race, and Juror Gender on Evidence Processing in a Murder Trial, 24 Behav. Sci. & L. 179 (2006); Mona Lynch & Craig Haney, Discrimination and Instructional Comprehension: Guided Discretion, Racial Bias, and the Death Penalty, 24 Law & Hum. Behav. 337 (2000).
24. Jessica M. Salerno & Shari S. Diamond, The Promise of a Cognitive Perspective on Jury Deliberation, 17 Psychonomic Bull. & Rev. 174 (2010).
25. James H. Davis, Mark F. Stasson, Kaoru Ono & Suzi Zimmerman, Effects of Straw Polls on Group Decision Making: Sequential Voting Pattern, Timing, and Local Majorities, 55 J. Personality & Soc. Psych. 918 (1988).
26. Solomon E. Asch, Effects of Group Pressure upon the Modification and Distortion of Judgments, in Groups, Leadership and Men: Research in Human Relations 177 (H. Guetzkow ed. 1951).
27. Robert Fitzgerald & Phoebe C. Ellsworth, Due Process vs. Crime Control: Death Qualification and Jury Attitudes, 8 Law & Hum. Behav. 31 (1984).
28. Claudia L. Cowan, William C. Thompson & Phoebe C. Ellsworth, The Effects of Death Qualification on Jurors’ Predisposition to Convict and on the Quality of Deliberation, 8 Law & Hum. Behav. 53 (1984).
29. Mona Lynch & Craig Haney, Mapping the Racial Bias of the White Male Capital Juror: Jury Composition and the “Empathic Divide,” 45 Law & Soc’y Rev. 69 (2011).
30. L. Richard Hoffman & Norman R. F. Maier, Quality and Acceptance of Problem Solutions by Members of Homogeneous and Heterogeneous Groups, 62 J. Abnormal & Soc. Psych. 401 (1961); Karen A. Jehn, Gregory B. Northcraft & Margaret A. Neale, Why Differences Make a Difference: A Field Study of Diversity, Conflict, and Performance in Workgroups, 44 Admin. Sci. Q. 741 (1999); Charlan J. Nemeth, Differential Contributions of Majority and Minority Influence, 93 Psych. Rev. 23 (1986).
31. Samuel R. Sommers, Lindsey S. Warp & Corrine C. Mahoney, Cognitive Effects of Racial Diversity: White Individuals’ Information Processing in Heterogeneous Groups, 44 J. Experimental Soc. Psych. 1129 (2008).
32. Michael I. Norton et al., Color Blindness and Interracial Interaction: Playing the Political Correctness Game, 17 Psych. Sci. 949 (2006); Jennifer A. Richeson & J. Nicole Shelton, When Prejudice Does Not Pay: Effects of Interracial Contact on Executive Function, 14 Psych. Sci. 287 (2003); Sophie Trawalter, Jennifer A. Richeson & J. Nicole Shelton, Predicting Behavior During Interracial Interactions: A Stress and Coping Approach, 13 Personality & Soc. Psych. Rev. 243 (2009).
33. Hoffman & Maier, supra note 30.
34. Margaret C. Stevenson et al., Racially Diverse Juries Promote Self-Monitoring Efforts During Jury Deliberation, 3 Translational Issues in Psych. Sci. 187 (2017).
35. Liana Peter-Hagene, Jurors’ Cognitive Depletion and Performance During Jury Deliberation as a Function of Jury Diversity and Defendant Race, 43 Law & Hum. Behav. 232 (2019).
36. Amanda Bergold & Margaret Kovera, Diversity’s Impact on the Quality of Deliberations, Personality & Soc. Psych. Bull. (2021).
37. Peters v. Kiff, 407 U.S. 493 (1972).