How do juries deliberate? So last week we heard how individual jurors
arrive at their preferred verdict when hearing the evidence presented at trial. We talked
about the sorts of things that influence them and how they combine information, typically
into a story, about the events that led to the offence. What happens when they have to
discuss their interpretation of the evidence and their preferred verdict with the other
jurors?
Well over the next two videos, we are going to talk about how juries deliberate to reach
a verdict, whether these deliberations influence individual jurors' views, and the different
ways that jury deliberations can unfold, and what sorts of things influence how jurors deliberate.
Now in terms of factors that might influence how a jury deliberates, one of the things
that people often think is important is the foreperson. This is the person chosen by the
jury to lead the group during discussions and also to be the spokesperson in the courtroom,
particularly when the verdict is returned. So, does who the jury selects as the foreperson
make a difference as to how the jury deliberates?
Well, lets start with how the foreperson is selected, and what they are typically like.
Usually the foreperson is elected by the jury. One view, put forward by the Morris Committee
in 1965, is that the foreperson should ideally possess the qualities of a good chairperson
but be no different from the other jurors. Saks and Hastie's 1978 research suggests that
the person chosen as the foreperson tends to be male, from a high socio-economic background,
be older, be the person who sits at the head of the jury table, and is the person who often
speaks first during deliberations.
Curiously though, Ellison and Munro 2010 found in a study with mock jurors, that when the
person who spoke first was a woman, it was still often the case that a male juror was
nominated to be the foreperson — the woman speaking first was often nominating a man
to be the foreperson.
A common view is that the foreperson is very influential. McCabe and Purves' 1974 research
suggests otherwise, however. In that study, the foreperson did not exert a greater influence
on the decision compared to the other jurors. In contrast, Devine and colleagues 2001 review
of 45 years of jury research argued that the foreperson has a big influence on the style
of jury deliberations — whether the jury focusses initially on trying to reach a verdict
or on systematically evaluating the evidence. As such, it's possible that the foreperson
might influence the verdict indirectly through the way in which the jury deliberates.
It's also worth noting that the jury foreperson tends to determine who speaks and when, and
so can shape the discussion in that way. Ellison and Munro's 2010 research and Manzo's 1996
research provide some evidence for this. They are certainly also viewed as being more influential
by the other jurors according to Diamond and Casper's 1992 study. He or she also speaks
more often than the average juror, they speak about 25-31% of the time during deliberations
according to Ellison and Munro. And consistent with this, Diamond and Casper in 1992 found
that the foreperson spoke about 1770 words in comparison to the average juror's 789 words.
Now much of what they said, however, was designed to help organise the jury rather than express
a verdict preference.
Ok, so the foreperson possibly doesn't seem to exert a big direct influence on the jury's
verdict but, as Devine and colleagues found in a review of jury research, the foreperson
is influential in deciding how the jury deliberates.
So lets look at how jury deliberation itself influences or changes jurors' decisions. What
are some of the features aside from the influence of the foreperson that might affect how juries
deliberate?
Let's start with the question of whether deliberation alters jury decisions. Now there has been
a general belief, which came from Kalven and Zeisel's influential study in 1966, that jurors
have already decided a verdict before they retire to deliberate. Thus, the thinking was
that deliberations did not have a big impact on jurors' decisions.
Now this doesn't really fit with what we know about outcomes of deliberations however.
Many juries don't start out with a unanimous agreement before discussing the case. There
will be a majority group of jurors who favour one verdict and a smaller minority group who
think differently.
Given that juries are able to reach agreement in the majority of cases, deliberation must
exert some influence on jurors' decisions.
Hastie and colleagues' 1983 research even showed that the minority of jurors prevailed
and were able to change the minds of the majority in 25% of cases. So deliberation is obviously
important, and one way of making sense of these two different sets of findings — that
jurors decide their verdicts before deliberation and that deliberation changes jurors' minds on the other hand
— is to distinguish between different types of deliberations. This is a point made by
Sandys and Dillehay in 1995.
One of the main distinctions identified by Lieberman and Krauss in 2009 is the difference
between verdict driven deliberations and evidence driven deliberations. And the work of Devine
and colleagues suggests that it is through the foreperson's preference for one of these
styles of deliberation that the foreperson can exert an influence on the outcome of the
deliberations.
Verdict driven deliberations are those types of jury group discussion focussed on reaching
a unanimous decision or a majority decision if the decision rule for the jury requires
only a majority decision. The discussion tends to be less about the evidence and more
about discussing the verdict options. Pressure might be applied to any holdout minority jurors
to get them to agree with the majority position. A characteristic of this type of deliberation
is frequent attempts to take a poll for the verdict, which has a consequence of identifying
any individual jurors who might disagree with the majority.
Now you saw this type of discussion at the start of the jury's deliberation in the Crime101
drama this week.
Evidence driven deliberations on the other hand, focus on a more systematic discussion
of the evidence that was presented at trial. For these types of deliberations, there will
be less of a focus on simply trying to pressure people into reaching a decision. The emphasis
is on evaluating the evidence rather than taking polls in an attempt to reach a verdict.
Now you saw this type of discussion towards the end of the jury's deliberation in the
Crime101 drama this week.
A moment ago, I mentioned different types of jury decision rule. The jury decision rule
is the required number of jurors needed for agreement for a verdict. In some jurisdictions, all jurors are required
to agree to the verdict before it is accepted by the court. This is called a unanimous decision
rule.
In other jurisdictions, a majority decision will be accepted by the court. The size of
the majority that will be accepted depends on the size of the jury. For a twelve-person
jury, this might be a majority of 10 or 11 out of 12. It can be a little more complicated
than this, however. The type of decision rule used can also depend on the offence that the
defendant is being tried for.
For the more serious offences, a unanimous rule might be required. In addition, in some
jurisdictions, even for the most serious offences, a majority decision will be accepted if the
jury is not able to reach aunanimous decision after a certain period of time has elapsed.
So the decision rule can vary by jurisdiction, by the nature of the offence, and also by
the time that the jury has been deliberating for. Now majority decision rules are often
favoured because of concerns about hung juries — these are juries that can't agree on a
verdict. Now this actually only happens in a tiny minority of cases. There have also
been some concerns expressed about the time taken by juries to deliberate.
So does jury decision rule have any effect on how the jury makes their decision?
Nemeth's 1981 research suggests that the majority decision rule is associated with: less participation
by minority jurors; the majority jurors paying less attention to the minority jurors; fewer
hung juries; deliberations taking a shorter time; and, perhaps problematically, a greater
likelihood of conviction and more errors in recalling the evidence.
Now why is this? Well, because the jurors in the majority are not required to convince
the dissenting minority about the correctness of the majority position, they can generally
ignore the minority jurors. Therefore, they can avoid discussing the evidence in any great
detail, and just apply social pressure in an attempt to reach a majority of the required
size.
Ok, so it seems that juries operating under a majority decision rule are prone to making
poorer decisions than those working under a unanimous decision rule. When discussing
the nature of the majority that will be accepted, I mentioned that juries can come in different
sizes.
In Australia, New Zealand and some other jurisdictions, criminal cases are heard by juries of twelve.
In the United States of America, following the Supreme Court decision in Williams and
Florida in 1970, as few as six jurors can hear a criminal case.
Thomas and Pollack (1992) used probability theory in 1992 to argue that six and twelve
person juries are equivalent in terms of how they make decisions. Researchers also often
use six person juries in their studies because logistically it is a lot easier to conduct
studies on juries of six compared to twelve (you need half as many people for a start).
Unfortunately the research suggests that juries of six and twelve do not function in the same
way. Six-person juries communicate less; are less likely to recall the evidence accurately
or examine the evidence thoroughly, and according to Saks's 1977 research are more likely to
reach agreement that is, they are less likely to hang. They are also less representative
of the community; and they often return different verdicts; and are more likely to convict.
These issues were identified by Hans and Vidmar's 1986 research.
Now, why is this? Well one of the main reasons for these differences between juries of six
compared to twelve is conformity.
Conformity occurs when people yield to real or imagined social pressure. Asch's 1955 study
was important in highlighting how groups bring about conformity, and illuminating the conditions
that enhance conformity and those that diminish conformity.
So let’s look at Asch’s paradigm. Asch gave a group of participants, who took part
in the study as part of a group, a picture of a vertical line followed by a second picture
of three vertical lines. Participants were asked in turn which of the three lines matched
the length of the original line.
In this example, the answer is clearly B. Now, in this study, all of the participants
except one, were working with the experimenter. So they weren't actually real participants,
they were what we call confederates. All of the confederates responded before the real
participant. On some trials the confederates all gave the correct answer, while on others
they gave an obviously incorrect answer — for example line A in our example.
Asch was interested in whether the real participant would go along with the group, and why. Asch
found that the vast majority of participants, 76% in fact, went along with the group and
conformed on at least one trial when the group was giving an obviously incorrect answer.
Asch argued that there were two reasons why conformity occurs like this. The first is
called normative influence. Here the real participant maintains his or her private view
about what the correct answer is, but conforms in public to avoid ridicule or social censure
from the rest of the group. The second is called informational influence — if a person
is not sure about what the correct answer is the group's response helps the real participant
to identify what the "correct" answer might be.
Interestingly, in some studies, Asch varied whether the group gave an unanimous but incorrect
answer, or whether there was non-unanimity in the views of the rest of the group. We've
seen in our example so far what an unanimous but incorrect answer would look like — the
rest of the group chooses the same but incorrect response. What happens however if the some
of the group chooses one incorrect response and the remaining group members choose another
incorrect response? What will the real participant do in this situation when there is non-unanimity?
Well Asch's studies show us that when there is non-unanimity in the views of other group
members, then the rate of conformity dramatically reduces. It is sufficient if only a single
other member of the group disagrees with the majority. That single dissenter doesn't even
have to agree with the real participants' response for conformity to be reduced, the
dissenter simply just has to give a different response to the majority.
So how does this relate to how juries deliberate, and jury size?
Well, let's try a thought experiment to illustrate this. Imagine a jury of six and a jury of
twelve. Let's imagine that the rate of dissent in the general population about a particular
issue is one in six. If we select people from the general population to form two juries,
one made of six people, and one made of twelve people, then we would expect the rate of dissent
to be represented in each jury like this.
The six-person jury will statistically have one person who dissents on this issue. The
twelve-person jury will have two people who dissent.
Asch's studies tell us that the pressures for conformity will be much greater in the
six-person jury compared to the twelve-person jury because it is much more likely that a
dissenter in a six-person jury will be on their own.
So the evidence suggests jury deliberation does influence individual jurors, and that
twelve-person juries working under a unanimous decision rule tend to be more systematic and
thorough in their decision-making.
As such, we've heard that juries with certain characteristics make better decisions. In
the next video, we will talk about whether juries as groups make better decisions compared
to individual jurors.