which case “guilty,” “not guilty,” and “hung” verdicts
were all relatively common.The Dynamics of Consensus
In most deliberations, it becomes obvious at some
point that all members do not favor the same verdict
and some jurors will have to change their minds if the
jury is to accomplish its task. A number of studies have
examined how juries go from an initial nonunanimous
distribution of preferences to a consensus verdict, and
two general sources of influence have been identified:
informational and normative. Informational influence
is associated with the content of the jury’s discussion;
it stems from the articulation of case “facts,” interpre-
tations, and arguments supporting a particular verdict.
Normative influencecomes about from a desire by
individuals to fit in with others and not be seen as
deviant, incorrect, or even disagreeable. In essence,
normative influence represents a pressure to conform
that is rooted in the desire to avoid the social costs
associated with standing apart from the collective.
Research on the dynamics of deliberation has
shown that majority factions exert both informational
and normative influence on minority (i.e., dissenting)
jurors. In particular, several different theoretical
models of majority influence converge on the conclu-
sion that the degree of influence exerted is propor-
tional to the size of the majority faction. In addition
to exerting normative influence in direct proportion
to their size, majority factions exert informational
influence as well. In this regard, majority factions
have a “sampling advantage” over minority factions
during deliberation in that they have more members
to draw on for evidence-related recollections, obser-
vations, and views consistent with their preferred ver-
dict. Conversely, in keeping with their smaller size,
minority factions are forced to rely primarily on
informational influence. Research has also shown
that juries tend to move away from their initial distri-
bution slowly at first but with increasing speed as the
majority faction grows and its influence increases in
a snowball-like fashion. In essence, as the majority
is given time to deploy its normative and informa-
tional advantages, it becomes harder and harder for
the minority to prevail. Interestingly, though, a few
studies have observed a momentum effect as well:
Once the jury begins moving in either direction
toward a verdict (whichever it happens to be), it
rarely stops and changes direction. This suggests thata key event underlying a “reversal” of the early
majority is when the first juror to change votes joins
the minority faction.
Opinion polling is one procedural variable that
may influence the dynamics of deliberation. Polling
during deliberation can vary on several dimensions,
including timing (e.g., early vs. late) and secrecy with
regard to individual votes. In particular, early opinion
polls conducted in a “public” fashion (where members
can observe how other jurors vote) may bring consid-
erable normative pressure to bear on members of the
minority faction to change their vote. In one clever
series of studies using mock juries with known verdict
preference distributions (i.e., an even 3:3 split or a 4:2
weak majority), polling was structured so that all
members of one faction voted first in sequence.
Consistent with the research on conformity, the first
member of the second faction was much more likely
than chance to switch his or her vote and join the fac-
tion that voted first. This was particularly so when the
vote was taken early and when the first faction voted
“not guilty.” Of note, some research suggests that
minority factions may have more influence if sub-
groups emerge (or are specifically formed) before a
general collective discussion and the minority faction
finds itself having a “local majority” in one or more of
the subgroups. Taken together, these findings support
the notion that the orderin which things are done may
distort the influence of faction size by affecting how
obvious the factions are.
Another stream of research on the dynamics of
deliberation has identified two general deliberation
“styles” that juries may adopt as they go about their
task: evidence driven and verdict driven. Evidence-
drivenjuries work toward the goal of establishing the
“facts” of the case as they see them before any dis-
cussion of the appropriate verdict. They spend a great
deal of time in reviewing the evidence and take their
first (and sometimes final) vote relatively late in the
process. On the other hand,verdict-drivenjuries take
an early first vote to get a sense of their members’
standing and then organize their discussion around the
verdict options and which one seems more appropri-
ate given what seems to be generally accepted by the
group. Research suggests that a substantial number of
juries (perhaps 33–50%) adopt a verdict-driven style,
and studies in which deliberation style was manipu-
lated suggest that its influence on the final verdict may
depend on other variables, such as the required legal
elements for the available verdicts.410 ———Jury DeliberationJ-Cutler (Encyc)-45463.qxd 11/18/2007 12:43 PM Page 410