Encyclopedia of Psychology and Law

map experimentally the differences and similarities

between the judgments of judges and juries before

concluding that judges are better than juries at specific

tasks (e.g., assessing risk) or that deliberations enable

juries to outperform judges on other tasks (e.g., assess-

ing conflicting testimony).

Finally, in addition to the few studies that have

exposed judges and laypersons to the same stimulus,

in several experiments with judges, researchers

conducted conceptual replications of the impact of

heuristics (e.g., anchoring, hindsight, framing) or of

extralegal factors, which had previously been tested

on laypersons. With a few exceptions, these experi-

ments have revealed that judges show a similar sus-

ceptibility to these cognitive illusions.

Shari Seidman Diamond and Pam Mueller

See alsoJuries and Judges’ Instructions; Jury Competence;

Jury Deliberation; Jury Selection; Leniency Bias

Further Readings

Diamond, S. S., & Rose, M. R. (2005). Real juries. In

J. Hagan (Ed.),Annual Review of Law & Social Science

(Vol. 1, pp. 255–284). Palo Alto, CA: Annual Reviews.

Eisenberg, T., Hannaford-Agor, P. L., Hans, V. P., Waters, N. L.,

Munsterman, G. T., Wells, M. T., et al. (2005).

Judge-jury agreement in criminal cases: A partial

replication of Kalven and Zeisel’s The American Jury.

Journal of Empirical Legal Studies, 2,171–207.

Guthrie, C., Rachlinski, J. J., & Wistrich, A. J. (2001). Inside

the judicial mind. Cornell Law Review, 86,777–830.

Kalven, H., Jr., & Zeisel, H. (1966). The American jury.

Boston: Little, Brown.

Robbennolt, J. K. (2005). Jury decision making: Evaluating

juries by comparison to judges: A benchmark for judging?

Florida State University Law Review, 32,469–509.

JURYDELIBERATION

Jury deliberationbegins when a trial ends and the jury

moves to a secluded location to discuss the evidence

and arrive at a decision. Understanding how juries

reach their decisions is a prerequisite for answering the

question of how well they serve their function in a

democratic society. Jury deliberation has been studied

empirically by social science researchers for more than

50 years now, but direct access to the jury room has

been always greatly limited due to a concern that any

“external” presence in the deliberation room could

influence the jury’s decision. As a result, researchers

have relied on two other methodologies to study jury

deliberation: experimental studies with mock juries

and posttrial reconstructions of actual deliberation via

surveys of and/or interviews with former jurors.

This entry summarizes what has been learned about

jury deliberation using these two methodologies. The

picture that emerges is one in which juries take their

task seriously and generally do a good job of reviewing

the evidence, although they often struggle with their

instructions. Influence in juries is a function of infor-

mation exchange and the pressure to conform. An

excellent predictor of the jury’s final verdict turns out to

be the distribution of verdict preferences on the jury’s

first vote; the verdict favored by the initial majority

ends up being the jury’s final verdict about 90% of the

time. However, the initial majority does not always pre-

vail, and these “reversals” represent some of the most

interesting products of jury decision making.

A General Model of Deliberation

A simple stage model provides a reasonable framework

for thinking about jury behavior in many, if not most,

deliberations. In the first stage, jurors get oriented

toward each other and their task. They settle in, intro-

duce themselves, select a foreperson, and discuss how

they will do things. In the second stage, which takes up

the bulk of the time spent in deliberation, jurors discuss

the evidence, take opinion polls (or “votes”), and con-

front disagreement among members. During this stage,

conflict often surfaces, efforts are made to persuade

other jurors to change their minds, and the jury moves

toward a consensus. In the final stage, the jury achieves

sufficient agreement (usually unanimity) to reach a ver-

dict, followed by attempts to smooth ruffled feathers,

reconcile individuals to the group’s decision, and help

everyone feel good about the collective verdict. Jury

deliberations vary considerably in length, but most last

somewhere between 2 and 4 hours.

TThhee FFoorreeppeerrssoonn

Juries typically receive little instruction regarding

how they ought to deliberate, but one thing they are

all told to do is choose a foreperson. Forepersons are

usually selected early, often immediately after mem-

bers assemble in the jury room but occasionally not

until the end of deliberation. Most of the time,

the selection process is brief and even perfunctory,

408 ———Jury Deliberation

J-Cutler (Encyc)-45463.qxd 11/18/2007 12:43 PM Page 408