Encyclopedia of Psychology and Law

proceedings on citizens who fail to respond to the jury

summons. Nearly two thirds of courts report some

form of follow-up on nonresponders, most often in the

form of a follow-up letter or second summons that

informs jurors that they have failed to report for jury

service and assigns them a new reporting date. Courts

that have formally evaluated this approach find that

the response rate to a second summons ranges from

35% to 50% and that individuals responding to a sec-

ond summons qualify for jury service in roughly the

same proportion as those responding to the first sum-

mons. If a juror fails to appear a second time, sanc-

tions can increase in severity from civil contempt

proceedings and fines to arrest and incarceration.

Practically, serious juror scofflaws constitute a rela-

tively small proportion of the population in most com-

munities. Thus, these more aggressive enforcement

measures often are conducted sporadically, but with a

great deal of publicity, as a deterrent to future jurors

who might ignore the summons.

The result of these efforts has been a remarkable

improvement in the diversity of jury pools over the

past three decades. Although some disparity in racial

and ethnic representation still occurs in most commu-

nities, typically the difference between the proportion

of a given minority in the community and the propor-

tion of that minority in the jury pool ranges from

2 to 4 percentage points. These changes, especially

expanding the inclusiveness of the master jury list and

reducing the term of service, have also dramatically

increased the proportion of the American population

that has experienced jury service—from 6% in 1977

to 29% in 2004. It may be this direct and personal

experience with jury service that has continued to bol-

ster popular support for the institution even in light of

the precipitous decline in the proportion of cases tried

by jury over the past 30 years.

Paula Hannaford-Agor

See alsoJury Deliberation; Jury Reforms; Jury Selection;

Story Model for Jury Decision Making; Voir Dire

Further Readings

American Bar Association. (2005). Principles for juries and

jury trials. Chicago: American Bar Association.

Hannaford-Agor, P. L., Waters, N. L., Mize, G. E., & Wait,

M. (2007). The state-of-the-states survey of jury

improvement efforts: A compendium report. Williamsburg,

VA: National Center for State Courts.

Hastie, R., Penrod, S. D., & Pennington, N. (1983). Inside

the jury. Cambridge, MA: Harvard University Press.

Munsterman, G. T., Hannaford-Agor, P. L., & Whitehead, G. M.

(Eds.). (2006). Jury trial innovations. Williamsburg, VA:

National Center for State Courts.

JURYCOMPETENCE

Many observers praise the abilities of juries in making

decisions in both criminal and civil cases. Others,

however, criticize the competence of juries, arguing

that juries are not effective legal decision makers.

Psychologists have conducted a variety of studies to

evaluate how juries make decisions, using simulation

and field experiments, archival data, and interviews of

jurors and judges. Overall, juries show a relatively

high degree of competence—jurors take their

decision-making tasks seriously, understand the

nature of the adversary process, attempt to make deci-

sions that achieve many (sometimes conflicting) goals

simultaneously, and perform at a level that is similar

to that of judges. However, there are clear areas in

which jury performance could be improved, and a

variety of procedural mechanisms have been devel-

oped to assist juries in their decision-making tasks.

Models of Juror Decision Making

Research has shown that jurors attend to the trial evi-

dence presented and show relatively high levels of com-

prehension and recall of the facts at issue. Mathematical

models of juror decision making—i.e., Bayesian mod-

els, algebraic models, and stochastic process models—

posit that jurors begin with a preliminary judgment and

update that judgment as evidence is introduced through-

out the trial. In contrast, the “story model” of juror deci-

sion making is an explanation-based model of juror

decision making that contends that jurors construct a

narrative story that best accounts for the (often conflict-

ing) trial evidence and then select the verdict option that

best fits that narrative.

Jurors’ Use of Evidence

In reaching their verdicts, jurors endeavor to make

decisions that account for the evidence and that follow

the law. Research has shown that in doing so, jurors

do tend to make use of the evidence that the law

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