top of page

The Advantage Blog

  • Theodore O. Prosise Ph.D.

FOUR OUT OF FIVE DENTISTS PREFER BRAND X, BUT THERE IS ONLY A 20% CHANCE OF THAT: JUROR DECISION-MAK


Statistics are everywhere—used, over-used, misunderstood, misused. Data, in the form of descriptive or inferential statistics, can be useful in developing understanding of conditions and events, and potentially informing or predicting outcomes. But there is considerable mistrust of statistics, as well as a high degree of skepticism regarding how advocates may use them. Here are a few important principles about how jurors use statistics in deliberations, based on our trial consulting observations from post-trial juror interviews, mock trials, jury focus groups, and shadow juries.

Confirmation Bias Statistics reveal patterns and put events into context, but their persuasiveness can be limited. Often in a trial setting, statistics are employed to confirm what someone already believes. So, as Vin Scully said, “Statistics are used much like a drunk uses a lamppost: for support, not illumination.” Instead of proving whether a claim should be accepted or not, statistics can be used to bolster the claim a juror wants to believe. The conclusion drives the use of the statistics, rather than data leading to a conclusion.

Manipulation Jurors often distrust the way numbers can be manipulated. They have an understanding that the “inputs,” and how one “cuts” the data shapes the result. If the statistics don’t confirm what a juror wishes to believe, they may be discounted. In the end, jurors do what they want with the numbers. If the numbers support their impressions of what is right, they will use them to support their views. If the numbers are inconsistent with their beliefs, jurors may dismiss them. Two popular quotes sum up this position – expressions that show not just a distrust of statistics, but also of those who rely on them. Benjamin Disraeli said, “There are three types of lies – lies, damn lies, and statistics.” Mark Twain wrote, “Figures lie, and liars figure.”

Statistics Versus Events A critical problem with simply regurgitating percentages and numbers is that the data are divorced from their context, and thus jurors can’t incorporate them into their narrative as they build it. If numbers can be part of a complex set of facts, characters, attitudes and values/principles, they can be meaningful elements of a jury trial. In many cases, the narrative elements of human reasoning trump the numbers.

“Facts” and events, incidents and anecdotes, are prominent in human beliefs. Ronald Reagan, the “great communicator,” was a master of what Michael Kochin called “the anecdotal style” (Five Chapters on Rhetoric: Character, Action, Things, Nothing, and Art, 2009, p. 84). The way he linked values, principles, morals, and anecdote, created an exceptionally powerful and persuasive story illustrating the principle he wished people to understand. It made Reagan’s rhetorical style powerful. Statistics are abstract, whereas anecdote is perceived as real—concrete, relatable, understandable, and repeatable.

In one mock trial involving a trademark, the jurors debated the merit of the defense’s confusion study, which was expensive and carefully-conducted research, revealing a low likelihood of confusion. The jurors, however, seized on two customer emails asking, “Is A the same product as B?” The emails won the day. Anecdotes, which are argument by example, are seen as grounded, material, and concrete. Mark Twain wrote, “Facts are stubborn things, but statistics are pliable.” Although an anecdote may be atypical, it is likely to have more presence in a juror’s mind because so much of our daily lives are experienced as a series of event-based episodes.

In terms of juror expressions, a single tragic event is highly meaningful. It is concrete and human. Joseph Stalin famously said that, “A single death is a tragedy; a million deaths are a statistic.” If tragic events are dismissed in too cavalier a fashion by counsel, the cultural concern of corporations “running the numbers” in their effort to callously determine if a recall is more expensive than settlements or the jury verdicts they may pay, such a line of deliberation can motivate jurors to make an award intended to “send a message” that a corporation can’t ignore. This conclusion is preceded by a juror saying, “Does someone need to die before they pay attention?” The question is rhetorical, the implication clear.

For many jurors, hindsight bias plays a significant role in their determinations. The event in question becomes critical in their assessment of negligence. As such, the claim becomes part of the support for the event, what argument theorists would label as circular argument. This can be a powerful, albeit misused, logic.

In many civil jury trials, negligence and causation are commonly centered on the jurors’ judgment of the case. Jurors may put more stress on the concrete event, rather than an assessment of probabilities of an injury or accident. Jury deliberations and verdicts are expressions of judgment. The “numbers,” if contrasted with what is seen as just, may (in the jury’s mind) become inconveniences to be swept or rationalized away. There is often a battle between the qualitative support and quantitative support for contrasting claims in trial. As Henry Clay put it, “Statistics are no substitute for judgment.”

Conclusion None of this is to say that statistics are poor forms of support. But there are potential limitations to their effectiveness, and that makes it more important to frame the numbers in the right way. Rather than depending on statistics or presenting them as the starting point of the defense, present the issues within an overall story-model defense. Use statistics to bolster your narrative argument, not as the central load- bearing structure of the case theory. Second, if presenting statistical findings from a study, visually outline the methodological steps taken to arrive at the data so that jurors understand that the process was thoughtful, reasonable, and careful. A simple “Step-up” of the “Step-forward” process/flow chart can make a big difference in orientating a jury to understand the sound thought that went into the study. Help the jurors see the how and the why that led to the findings, not just the expert’s credentials, a rush through the method, and a quick arrival to the what of their findings. Third, avoid using statistics as an excuse for inaction; instead help jurors understand why certain actions were taken, or not taken, based on proactive assessment and understanding of the individuals involved in any decision-making in the underlying events at issue. Fourth, use trial graphics to visually depict statistical probabilities. Help jurors see the odds in relatable, visual and tangible terms, not just in decimal points and percentages.

bottom of page