narina nuñez & sean m. mccrea department of criminal ......juvenile defendant, varying in age,...

Running head: JURY DECISION MAKING RESEARCH 1

Jury Decision Making Research:

Are Researchers Focusing on the Mouse and Not the Elephant in the Room?

Narina Nuñez & Sean M. McCrea

Department of Psychology, University of Wyoming

Scott E. Culhane

Department of Criminal Justice, University of Wyoming

Preprint of Nuñez, N., McCrea, S. M. and Culhane, S. E. (2011), Jury decision making research: Are researchers

focusing on the mouse and not the elephant in the room?. Behav. Sci. Law, 29: 439–451. doi: 10.1002/bsl.967

Full version

http://onlinelibrary.wiley.com/doi/10.1002/bsl.967/full

JURY DECISION MAKING RESEARCH 2

Abstract

The concerns of jury research have extensively focused on subject selection, yet larger issues loom. We

argue that observed differences between students vs. non-students in mock juror studies are

inconsistent at best, and that researchers are ignoring the more important issue of jury deliberation.

We contend that the lack of information on deliberating jurors and/or juries is a much greater threat to

ecological validity and that some of our basic findings and conclusions in the literature today might be

different if we had used juries, not non-deliberating jurors, as the unit of measure. Finally, we come full

circle in our review and explore whether the debate about college and community samples might be

more relevant to deliberating versus non-deliberating jurors.


Jury Decision Making Research:

Are Researchers Focusing on the Mouse and Not the Elephant in the Room?

The tension between experimental control and ecological validity is present in many applied

psychological research endeavors but is probably crucial in jury decision making studies. There has

always been a question about whether scientists can adequately study jury decision making in the lab

(e.g., Bornstein, 1999; Bray & Kerr, 1979; Diamond, 1997), and researchers typically attempt to add

features to their studies (e.g., provide videotaped or audio-taped testimony) to enhance ecological

validity. Diamond (1997) noted that there were several methodological considerations which could

potentially threaten the validity of any study, such as the use of inadequate sampling, simulations of

trials that were inferior in quality, a lack of deliberation by jurors in the true jury form, dependent

variables that were inappropriate, missing data from the field that corroborated research findings, and

the lack of real consequences because of the role-playing nature of decisions. Recently, sample selection

has been seen as an area of growing concern.

Reviewers of grants and manuscripts have become increasingly critical of the use of college

student populations as mock jurors in jury decision making studies. In our experience, we have had to

add increasing justifications in our manuscripts when we use college student samples, and have added

community samples to grant proposals after receiving feedback from reviewers encouraging such

inclusion. The fact that researchers who have used college samples in their work typically describe their

sample as a research limitation in their published work (e.g., Golding, Bradshaw, Dunlap & Hodell, 2007;

McCoy, Nuñez, & Dammeyer, 1999) suggests that psycholegal researchers, in general, are being

encouraged to move from college to community samples in their work. The concern about sample

selection has some face validity because it is typically community members, not college students, who

make up the jury panels. Indeed, in most jurisdictions, college students comprise a very small

percentage of the jury pool. Further, college students differ from community samples in a number of


ways. They are younger, more educated, less likely to be married, less likely to have served on a jury, etc

(Nunez et al., 2007). Thus, at first blush it appears that criticisms of college student samples are

defensible.

We argue in the present paper that, while these criticisms have some face validity, there is often

no theoretical reason to suspect such a difference, and only inconsistent empirical support for such

claims. Further, we argue that the debate about college versus community samples has obscured a more

important weakness of the jury decision research that Diamond (1997) noted: the fact that the vast

majority of the published research concerns non-deliberating mock jurors. We contend that the lack of

information on deliberating jurors and/or juries is a much greater threat to ecological validity. In

addition, we argue that some of our basic findings and conclusions in the literature today might be

different if we had included juries, not non-deliberating jurors, as the unit of measure. Finally, we come

full circle in our review and explore whether the debate about college and community samples might

actually be more relevant to deliberating versus non-deliberating jurors.

College versus Community Samples in Non-deliberating Juror Studies

In order to examine the importance of utilizing college versus community samples in juror

studies, it might be helpful to conceptualize the juror decision making literature into two different types:

process studies and content studies (see Stroebe & Kruglanski, 1989, for a similar distinction). Process

research attempts to define the underlying processes and mechanisms that impact juror decisions. For

example, several researchers have attempted to examine how jurors reason about a case and make

decisions about guilt or innocence (e.g., Bourgeois, Nuñez, Perkins, & Franz, 2002; Pennington & Hastie,

1986). Others have examined how modifying judicial procedures, such as allowing jurors to take notes

during trial or altering jury instructions to reduce racial bias, can help people remember information and

make better decisions (e.g., Nuñez, Bourgeois, Adams, & Binder, 2004; Shaked-Schroer, Costanzo, &

Marcus-Newhall, 2008). Content research attempts to examine how different case contents might


result in different decisions. Examples of this type of research include studies that look at how race of

the defendant, type of case, age of the victim, etc. impact verdicts (e.g., Bottoms, Golding, Stevenson,

Wiley & Yozwiak, 2007; Nunez, McCoy & Shaw, 1999). The importance of a college or community

sample might differ depending on whether one is conducting process or content research.

Process research by its very nature attempts to identify universal human cognitive, social, or

social-cognitive processes that underlie decision making. Moreover, because such work is focused on

theory testing, there can be less concern about possible sample differences. For example, in a recent

paper, Ruva and McEvoy (2008) explored how pre-trial publicity affected later decisions and memory for

information that was presented at trial. College student participants read a packet of news stories about

crimes taken from an on-line news source. Some of the stories contained information about a case that,

five days later, would be presented in a videotaped trial. The researchers found that, not only did the

pre-trial information affect verdicts, but mock jurors also misattributed some of the information they

read in the news stories to evidence presented at trial. That is, mock jurors used the pre-trial evidence in

their decisions, but then falsely attributed the source of the information to the trial. The findings fit

nicely with psychological theory regarding source monitoring (Johnson & Raye, 1981) and research that

demonstrates that information presented in one context can be inaccurately attributed to another

context (e.g., Durso, Franci, Reardon, & Jolly, 1985; Poole & Lindsay, 1995).

In another example of process research, Wiener, et al. (1994) examined how counterfactual

thinking affected judgments of negligence in a civil suit. After reading about a case that involved a

workplace injury, participants were asked to come up with examples of events that could have avoided

the workplace injury, prior to rendering their verdict. The researchers found that engaging in

counterfactual thinking (i.e., engaging in an exercise that listed events that would have avoided the

injury) altered mock juror’s perceptions of the defendant’s behavior which in turn affected their verdict.

Specifically, the counterfactual thinking altered participants’ views about whether the company’s


behavior was normal and whether they had provided adequate care for the worker, which then led to

fewer pro-defendant verdicts.

The question that arises is whether Ruva and McEvoy (2008) or Wiener et al. (1994) would have

observed qualitatively different results had they used community rather than a college samples. There is

little theoretical reason to suspect that memory and source monitoring errors or counterfactual thinking

operates differently in a college or community sample as a result of differences in education, marital

status, and so on. Empirical evidence suggests that these processes are even unrelated to general

intelligence (Henkel, Johnson, & De Leonardis, 1998). Unless there is a reason to suspect that differences

exist, we argue that the college versus community sample debate is of little relevance to research that

examines how underlying psychological processes affect decision making. In the case of source

monitoring, the only theoretical reason to suspect such differences would be the higher average age of

community samples. As past work has shown, accurate source monitoring is significantly worse among

older adults (specifically, age 64 and higher; Henkel et al., 1998; Mitchell, Johnson, & Mather, 2002). As

a result, one might suspect that source errors would be stronger among community samples. However,

even here the differences that might be observed in an older sample are one of degree rather than of

qualitatively different processing of information. Moreover, because a community sample would be

relatively heterogeneous, the more interesting question in our view would be to what extent a jury as a

whole would be influenced by the incorrect recollections of individual jurors. We return to this issue

below. Although we have focused on the examples of source monitoring and counterfactual thinking,

we argue that process research should be less susceptible to criticism of sampling for the reason that

these processes are likely to be relatively universal (see also Stroebe & Kruglanski, 1989). In sum, jury

studies that test psychological theory may not need to sensitive to sampling issues, however, the same

may not be said for content research.


Content research might yield different results in college versus community samples. Moreover,

the goal of content research is more frequently centered around predicting real-world outcomes, and so

issues of sampling are of greater concern. For example, because community samples tend to be older,

with more life experiences, they might view people and cases differently. If one studied the impact of

elderly witnesses on juror decision making it would be reasonable to expect that young college students

might react differently than an older community sample. Because there is reason to suspect that some

cases might yield different results among college and community samples, it is important to test this by

comparing both types of samples on a variety of court cases. This has certainly been done, and by and

large data has yielded surprisingly few community-college sample differences (see for example,

Bornstein, 1999). In one study that examined perceptions of witnesses, researchers varied the

characteristics of an elderly witness (Nuñez, McCoy, Clark, & Shaw, 1999). Participants were presented

with one of three elderly stereotypes: frail senior citizen, grandfather, or elder statesman. The authors

collected data from community and college samples, reasoning that perceptions of the elderly would

likely differ in the two samples. What they found, however, was that both samples returned more guilty

verdicts when the witness was an elder statesman than when the witness belonged to one of the other

two elderly categories. There were no community-college sample differences on the dependent

variables of interest despite the fact that the college sample was considerable younger (Mcollege = 21.51

years; Mcommunity = 39.15).

In another study, researchers examined perceptions of juveniles who had committed murder

(Nuñez, Dahl, Tang, & Jensen, 2007). They presented participants with a short case history vignette of a

juvenile defendant, varying in age, gender, relationship to the victim, and abuse history. Participants

were asked to recommend either adult or juvenile court for the defendant. Reasoning that a younger

college sample might differ from an older sample, Nuñez et al. (2007) obtained data from three sources:

1) a college student sample (Mage = 22.58), 2) a community sample of residents living in the same


community as the students (Mage = 41.90), and 3) an internet sample of adults living throughout the

country (Mage = 33.45). Despite expecting differences, the authors found that sample type did not predict

any of their dependent variables. Nor were there any interactions between sample type and the

independent variables. In fairness, though no sample differences were found, the study did not actually

ask mock jurors to make verdict decisions in the case. Instead it tapped attitudes about the proper

jurisdiction for juvenile offenders. If the study asked participants to render verdicts, it is possible that

community-college differences might have emerged.

Though we described only two content studies that have failed to find college-community

sample differences, there are many others. For example, Bornstein, Kaplan, and Perry (1999) examined

perception of child abuse in a college and community sample. Cutler, Dexter, and Penrod (1989)

examined how expert testimony affected decisions and compared a college and community sample.

Roberts and Golding (1991) examined perceptions of criminal responsibility in a case that raised the

insanity defense with a college and community sample. In none of these studies were sample

differences found. In fact, in a review of 26 studies that compared college and community mock juror

samples, most of which were content studies, Bornstein (1999) found that few studies had any sample

differences. More importantly, when college-community differences were found, there was no

interaction between sample type and other independent variables. For example, Cutler, Dexter, and

Penrod (1989) found that their community sample returned more guilty verdicts than did their college

sample. However, both samples were influenced by the primary independent variable; expert testimony

on problems with eyewitness memory. Both college and community samples were more skeptical about

eyewitness testimony and returned fewer guilty verdicts when they were exposed to expert testimony.

However, there remain reasonable situations in which students and community members could

differ. Imagine a case of child sexual abuse. It is reasonable to expect the defense attorney to utilize

peremptory challenges on potential jurors who are parents in the venire. At the same time, prosecutors


might seek to retain as many as parents as possible. Here, we have differences in the two possible

samples (i.e. community members are more likely to be parents) which may translate into verdict or

sentencing differences. Individual characteristics, such as age and education, have an impact on decision

making (Mills & Bohannon, 1980). The restricted range of both age and education in college samples

would likely prevent researchers from identifying these individual difference variables. Indeed, many

possible legal situations have not been tested with both samples. Until empirical research comparisons

flesh out various scenarios, we will not know for certain whether the two types of samples differ.

Although we acknowledge that there remain legitimate research questions to be addressed in

this area, we suggest that other issues of ecological validity may be of graver concern than the issue of

sampling. As the title of our paper implies, jury decision making researchers may have paid too much

attention to the mouse in the room and ignored the bigger problem in jury research: the elephant in the

room. We argue that sample issues are the mouse and that the bigger problem facing the jury decision

making literature, the elephant if you will, is the lack of emphasis on deliberating jurors and juries.

However, we also suggest that once researchers start conducting deliberation studies, the college versus

community sample issue may be much more critical.

Deliberating Jurors and Juries

Despite the fact that our judicial system requires group rather than individual decisions, the

majority of the jury research has been done on the juror level and then extrapolated to the jury.

Certainly one of the main reasons for this practice is the enormous difficulty and time required for group

research. Each group made up of multiple participants represents only one data point. A juror research

project that requires 60 participants would require 360 for a jury study (using 6 person juries). However,

the social psychological literature is replete with examples of how group decisions differ from individual

decisions. For example, group judgments tend to be more extreme than are individual judgments, an

effect labeled group polarization (Teger & Pruitt, 1967; Isenberg, 1986). Polarization can be caused by


the consideration of persuasive arguments or information, particularly when the judgment is inherently

ambiguous (Isenberg, 1986; Sherif, 1935). For example, Kaplan (1977) provided mock jurors with trial

evidence designed to lead them to the conclusion that the defendant was either guilty or innocent.

Participants were then given a list of evidence from the case that supposedly had served as the basis of

judgment for other jurors. This information was manipulated to be either consistent or inconsistent with

the participant’s initial judgment. Ratings of both guilt and recommended punishment became more

extreme when the information provided by “other jurors” was supportive of the participant’s initial

recommendation, and became less extreme when the other jurors provided information that was

contrary to the participant’s initial recommendation.

Polarization can also occur when individuals seek approval from the group (Asch, 1951;

Isenberg, 1986). Individuals may abandon their own opinion simply to avoid conflict with others. Such

conformity was demonstrated in a series of classic studies conducted by Asch (1951). Individuals were

asked to make a series of easy perceptual judgments after hearing the (incorrect) judgments of a

number of confederates. Participants reported agreement with the majority on over a third of the trials,

despite the fact that the group’s judgment was obviously wrong. In extreme cases, dissent may be met

with explicit disapproval or social sanction (Janis, 1982).

In many jury situations, conformity and polarization are likely to occur because of the

requirement of a unanimous verdict. Indeed, instructions to reexamine one’s views in order to come to

a unanimous verdict increases conformity pressure on minority dissenters (Kassin, Smith, & Tulloch,

1990). It is perhaps not surprising then that past research has typically found a “majority-rules” principle

at work among juries, in which verdicts tend to reflect the majority of predeliberation recommendations

(e.g., Davis, 1973; Devine, Clayton, Dunford, Seying, & Pryce, 2001; Kalven & Zeisel, 1966). Although one

might be tempted to argue that the majority-rules finding indicates that deliberation is uninteresting or

unimportant, we hold this view to be misguided. If jurors never changed their vote as a result of


deliberation, the majority of cases would end in a hung jury. Devine et al. (2001) reported that first

ballots were unanimous in only 35% of the cases examined in their review of the literature. Nonetheless,

only 34% of cases with initial disagreements ended in a hung jury. In other words, deliberation played a

role in deciding more than 42% of all cases. Moreover, it does not seem to be the case that one can

straightforwardly extrapolate jury verdicts from the distribution of juror recommendations. A meta-

analysis of jury studies conducted by MacCoun and Kerr (1988) and subsequently replicated by Devine

et al. (2001) shows that there is an asymmetry in eventual verdicts in favor of acquittal, such that

majorities favoring conviction are overcome in a nontrivial number of cases. A further complicating

factor is that, despite any strong recommendations for a unanimous verdict, juries have the possibility of

being hung, which is not an option afforded individuals (Davis, 1973). Thus, an interesting question for

future research is to document how influence takes place (i.e., either due to normative social pressure

or the sharing of information) and to determine which factors may lead to increased minority influence

or stalemate within juries.

In addition to these considerations of social influence within groups, group decisions also differ

from individual judgments in terms of process and, as a result, accuracy. For example, group discussions

are subject to process loss (Steiner, 1972). That is, important pieces of information may not be shared

with the group for various reasons, including failure to communicate effectively (e.g., talking over one

another, forgetting what one was going to say, etc.), or social loafing. Increased group size reduces the

perceived responsibility any one individual feels for contributing to the discussion, and so vital

information may not enter into the discussion (Latané, Williams, & Harkins, 1979, Stasser & Titus, 1985).

Along similar lines, groups may fail to appropriately weight the views of more competent

members (Sorkin, Hays, & West, 2001). Applying signal-detection theory to the case of group decision-

making, Sorkin et al. (2001) could show mathematically that the performance of a group that fails to

deliberate will be considerably lower than ideal, particularly when a unanimous verdict is required.


These so-called “Condorcet” groups fail in large part because equal weight is given to both incompetent

and competent members. When Sorkin et al. (2001) allowed group interaction in completing a

perceptual task, participants gave weight to member’s judgments in accordance with their actual

expertise at the task, and group performance improved. Thus, to the extent that groups are able to

adequately share information and identify more competent members, they can come to decisions that

are qualitatively better than those of individuals (see also Davis & Harless, 1996). Important for the

current discussion, these findings suggest that the judgment of a jury may differ substantially from those

of any one juror. Indeed, there are several studies in the psycholegal area that directly demonstrate

differences between juror and jury decisions.

In one study, London and Nuñez (2000) examined jurors’ ability to ignore inadmissible evidence

in their decision making. At the time the study was done, the conventional thinking was that jurors could

not ignore inadmissible but powerful evidence. There were many studies that demonstrated that jurors

allowed inadmissible evidence to creep into their judgments (e.g., Kassin & Summers, 1997). However,

most of the research had been done without deliberation. A meta-analysis of studies of inadmissible

evidence, examining nearly 50 studies and over 8000 participants found very few instances of

deliberation (Steblay, Hosch, Culhane, & McWethy, 2006). As evidence presented should be the sole

consideration for determining guilt or awarding civil judgment, it seems strange that so many different

laboratories would ignore this crucial process when determining the impact of inadmissible evidence on

decision making.

The question asked by London and Nuñez (2000) was whether group deliberation would

enhance or suppress pre-deliberation biases. In two studies, mock jurors were assigned to either an

admissible, inadmissible, or control condition. The defendant was charged with taking nude pictures of a

neighborhood child, and during trial it was revealed that pictures had been found (Study 1) or that the

defendant had been accused previously of committing the same crime (Study 2). Prior to deliberation,


jurors in the inadmissible conditions yielded almost as many guilty verdicts as did mock jurors who were

exposed to the same information but who were told that they could use the information (i.e., the

admissible condition). After deliberations, however, the number of guilty verdicts in the inadmissible

condition dropped significantly. In both studies, the decisions of deliberating juries in the inadmissible

conditions were not significantly different from those of juries in the control condition who did not

receive the damning evidence. Deliberations of the mock jurors eliminated the influence of inadmissible

evidence on judgments, in direct contrast to the effects found at the individual level.

In another study, researchers examined whether deliberations led to superior reasoning about a

case (McCoy, Nuñez, & Dammeyer, 1999). Participants watched a video of a murder trial and were later

asked to reason about the case using the types of questions that Kuhn and her colleagues (Kuhn,

Weinstock, & Flaton, 1994) have used to study reasoning ability. According to Kuhn et al. (1994), ability

to consider alternatives, reflect on evidence, and provide examples of evidence that runs counter to our

own judgments are signs of higher level reasoning. Thus participants watched a murder trial and were

asked to decide a verdict of 1st degree or 2nd degree murder, voluntary manslaughter or not guilty/self-

defense. They were asked to determine their verdict and give reasons for choosing the verdict and then

to generate the evidence for and against the other verdict options. Jurors were randomly assigned to: 1)

answer reasoning questions after viewing the trial, 2) answer reasoning questions after deliberating with

a group of people, or 3) answer the reasoning questions after ruminating about the details of the trial

and taping the ruminations. The researchers found that jurors who answered the questions after

deliberations had significantly higher reasoning skills than either the pre-deliberation or rumination

group. The researchers suggested that talking with others, defending one’s views, and hearing other

views helped individuals to reason better about the case. The results of the study suggest that we would

underestimate case reasoning skills if we only examined non-deliberating jurors.


In a derivation of a study described earlier, Ruva, McEvoy, and Bryant (2006) examined how pre-

trial publicity impacted juror and jury decisions. Participants read a series of news articles about crimes

(half of whom were exposed to the details of a murder that they would later be asked to judge). Four

days after being exposed to the news articles, participants watched a videotaped murder trial. The

authors predicted that the impact of pre-trial publicity that they found in their juror study (Ruva &

McEvoy, 2008) would be magnified following deliberations. In other words, the authors predicted that

prior biases would be magnified in the individuals who deliberated. What they found instead was that,

although pre-trial publicity had the predicted effect on individuals prior to deliberations, deliberations

led to fewer guilty verdicts in those conditions. In addition, deliberating jurors in the pre-trial publicity

condition answered more items correctly on the source monitoring test than non-deliberating jurors.

That is, they were less likely to claim that information, presented in the pre-trial news articles was

actually presented at trial. Similar results were obtained by Kerwin and Shaffer (1994) in a study of the

impact of inadmissible evidence. Whereas individual jurors tended to ignore a judge’s instruction not to

consider certain evidence, deliberating juries tended to obey this instruction. As a result, although

individual jurors and predeliberation juries made equivalent verdict recommendations, postdeliberation

juries made more lenient verdict recommendations. Kewin and Shaffer (1994) also found that the

correlation between personal sentiment and verdict was significantly higher for the individual jurors

than for the deliberating juries, suggesting that deliberation led individuals to put aside their biased

personal feelings and follow the instructions of the judge.

We have reviewed several studies that explicitly compared deliberating and non-deliberating

jurors. All found important differences in the deliberating jurors. Extant data suggests that the quality of

the decision can be enhanced through deliberations. After deliberating, jurors are less biased by

inadmissible evidence, reason at a higher level about case material, and may be less influenced by pre-

trial publicity. Likewise, Devine et al.’s (2001) review of juries found improvements in studies involving


deliberating jurors. Specifically, jurors in deliberating conditions had a better understanding of the legal

instructions provided. Though we have only reviewed a few studies, all suggest that deliberations can

serve to correct initial individual biases. We do not mean to suggest that deliberation always results in

superior decisions. As an example of a study that did not find a significant improvement in jurors after

deliberation, Wiener and his colleagues examined understanding of judicial instructions at a sentencing

phase of a capital trial for pre- and post-deliberation jurors (Wiener et al., 2004). They found that prior

to deliberations jurors’ accuracy of legal definitions was better than chance but still quite low. After

receiving state approved pattern instructions and having the chance to deliberate with others,

comprehension did not significantly increase. Thus, deliberations may improve final decision making in

some cases, it is not a panacea for bad decision making. Importantly, though, the research appears to

show that deliberating jurors are not the same as non-deliberating jurors.

The Possible Importance of College and Community Samples in Deliberating Juries

In this final section, we come full circle in our arguments and suggest that once researchers

begin to include deliberations as part of their methods, the college-community sample debate may

become more important. In fact, it may be that college versus community sampling becomes crucial

once deliberating jurors become the norm. Specifically, there is a body of literature in the social and

industrial psychological literature that examines heterogeneity of group composition and group decision

making. This literature is relevant because samples of juries drawn from a college population are likely

to be more homogeneous than samples drawn from the community at large and differences in

homogeneity of mock jury groups may lead to different decision outcomes. If so, this would argue

strongly for engaging community samples in the jury research.

Two meta-analyses highlight some of the major findings from the homogeneity/heterogeneity

literature. Horowitz and Horowitz (2007) examined the literature on team diversity and team outcomes,

specifically testing whether bio-demographic diversity (e.g., age, race, gender) or task diversity (e.g.,


expertise, cognitive ability) impacted group decisions. The researchers identified 35 peer reviewed

articles that included 78 different correlations that could be tested. The researchers found that bio-

demographic diversity (i.e., variation in demographic traits) was not a significant predictor of quality or

quantity of group decisions, but that higher task diversity predicted better decisions. That is, groups that

were heterogeneous in terms of expertise and experience typically performed better than less diverse

teams. In a somewhat similar meta-analysis, Devine and Philips (2001) examined whether the cognitive

ability of individual group members predicted quality of group decision making. They tested whether

cognitive ability (mean group member score, highest member score, lowest member score, and

standard deviation of scores) predicted team performance. They found that mean group score had the

strongest positive relationship with team performance. Low and high member scores also predicted

team scores but not as strongly. Interestingly, standard deviation of scores (which would have indicated

a more heterogeneous group) was unrelated to team performance.

The burgeoning literature on group homogeneity/heterogeneity recently led van Knippenberg,

De Dreu, and Homan (2004) to develop the Categorization Elaboration Model, outlining the

circumstances under which heterogeneity is likely to improve or undermine group performance. The

model holds that heterogeneity can improve group decision making by bringing a greater range of

information and expertise to the task, fostering greater elaboration of relevant information. In a jury

setting, heterogeneity could involve a range of relevant experiences, such as prior service as a juror,

similarity of experience to the defendant or the victim, or expertise with regard to aspects of the case.

On the other hand, diversity can also create intragroup divisions which undermine these same

processes. For example, diversity in gender, age, race, or socioeconomic status may segregate juries in

such a way that they refrain from information-sharing and fail to elaborate on task-relevant information.

Research examining the effects of heterogeneity in the area of jury decision making is less common, but


recent findings suggest there may indeed be important effects of jury diversity on the deliberation

process.

In one study, Golding, Bradshaw, Dunlap, and Hodell (2007) investigated how gender

composition of a jury impacted decisions. The literature has consistently found that, in child sexual

abuse cases, women mock jurors are consistently more pro-victim (e.g., render more guilty verdicts,

believe the victim) than are men (for a review see Bottoms, et al., 2007). Golding and his colleagues

(2007) tested whether majority men (1 woman and 5 men) and majority women (5 women and 1 man)

juries would arrive at different decisions. Specifically, they predicted that majority women juries would

render more guilty verdicts than would majority men juries, and that people in majority women juries

would be more likely to change a pre-deliberation not guilty vote to a guilty vote after deliberation,

relative to people in majority men juries. As expected, they found that women were more pro-defense

than were men prior to deliberations. Consistent with their prediction, they also found that, after

deliberation, majority women juries returned guilty verdicts more often than majority men juries.

Golding and his colleagues (2007) were quick to mention, however, that the women majority juries had

an asymmetric pre-deliberation bias towards guilt (i.e., the majority were already leaning towards guilt).

As discussed above, if a majority of group members have a pre-deliberation bias towards one outcome,

the group decision often reflects that majority (MacCoun & Kerr, 1988). Thus, it may not have been

gender of the majority, per se, that determined the number of guilty verdicts in the study. Rather, the

distribution of pre-deliberation views may have biased the ensuing deliberation process.

In a similar vein, Sommers (2006) explored racial diversity of the jury and how it impacted

decisions and deliberations in the trial of a Black defendant. Though no differences were found in group

verdict, compared to all White juries, mixed race juries discussed more case facts during deliberations,

and this was true for both the Black and White mock jurors. Also, inaccuracies that were brought up

during deliberation were less likely to be corrected in the all White juries than in the mixed race juries.


Thus, the results suggest that heterogeneity (at least with regard to racial diversity in a trial of a Black

defendant) could lead to greater information sharing and superior deliberations.

Finally, Gastil, Burkhalter, and Black (2007) conducted a jury study that more directly addressed

the issue of group homogeneity/heterogeneity. A sample of 267 community members, who were to

serve on deliberating juries were recruited to complete a survey both before and after their jury service.

Pre-deliberation questionnaires assessed such things as educational attainment, political affiliation and

partisanship, political knowledge, and political self-confidence. Post-deliberation questions assessed the

quality of the deliberations (e.g., “Jurors thoroughly discussed the relevant facts of the case.” “All of the

jurors listened respectfully to each other during deliberations.”). They also assessed juror satisfaction

with the deliberations and final verdict. Though the researchers predicted that diversity (either partisan,

educational, etc.) would lead to poorer deliberation evaluations, because such diversity would impair

the ability of the jury to reach common ground in their deliberations, the results did not support their

predictions. The ideological diversity of the jury was not related to deliberation experience and diversity

did not prevent careful deliberation.

The body of work described in this section suggests that heterogeneous groups might deliberate

and make decisions differently from homogeneous groups. In some instances homogeneity has been

found to lead to superior decisions (e.g., leading to less interpersonal conflict; Devine, 1999) and in

others heterogeneity has been found to lead to superior decisions (e.g., leading to a greater exchange

of information; Sommers, 2006). What is clear, however, is that heterogeneity/homogeneity is relevant

to college versus community sampling, regardless of whether one is defining homogeneity by race,

cognitive ability, life experience, etc. In general, we would expect that college samples would be more

homogeneous and less heterogeneous than community samples. To the extent that a particular case

might favor homogeneity, one might expect that decisions by a group of college students would be

superior to a group of community residents. To the extent that a particular case might favor


heterogeneity, one might expect decisions by a group of community residents to be superior to a group

of college students. The important point here is that there is reason to suspect that group decisions by

community and college samples would differ.

The good news, however, is that research that has shown homogeneity/heterogeneity

differences typically find that group composition effects are small (e.g., Devine & Philips, 2001). But

since most of the research has been done on topics that are relevant to group decisions in the business

world (e.g., create a strategic business plan for a fictional regional airline; Devine; 1999) there is a dearth

of information about jury decision making. Clearly, more research needs to be done, and research from

the management field as well as recent theoretical models such as CEM may provide a guide to

researchers interested in these important questions.

Conclusion

In this paper, we argue that differences between college and community samples in juror

decision research are inconsistent at best. Data supporting community-college differences is not

compelling in either the process or content juror research. We argue that a more glaring problem with

our body of work is the dearth of research that includes deliberating mock jurors.

We congratulate those researchers who have dedicated their work to the strenuous task of

investigating variables at the group level. However, such research comprises a minority portion of legal

decision making research. Devine and colleagues (2001) summarized 45 years of jury decision making

research and found 206 published articles that included deliberation. Though that is encouraging, it is

still an average of only 4.6 articles a year. They recommended that researchers use randomly selected

members of the local jury pool as participants in future studies. Yet, their review noted that most

studies did not find a difference in the two types of samples.

Once we start employing deliberating jurors in our study, the importance of sampling (college

versus community) may indeed become salient. If so, researchers will need to incorporate deliberating


community members in their work. We have no doubt that this possibility causes a collective groan

among jury researchers. It is difficult enough to recruit community members without also having them

deliberate. Though this would make jury research even more difficult to conduct, we may need to do so

in order to truly test how process and content variables are likely to impact decision making in real

juries.


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