Primed to Decide: How Impactful are Opening Statements?

My Cousin Vinny

By Thomas M. O’Toole, Ph.D.

Primacy and recency are, by far, the most popular theories of persuasion that arise in my discussions with attorneys. I have never heard an attorney mention “elaboration likelihood model,” but references to primacy and recency seem to come weekly at times. Primacy refers to the idea that what is presented most remains the most salient and, consequently, impactful for the audience. Recency is the opposite idea that an audience is most impacted by what it heard last.

Applied to a litigation setting, the primacy/recency debate translates to a popular debate about whether opening statements or closing arguments are more important. The traditional belief among lawyers (and in some respects, this author) is that opening statements are the most important part of trial. Many attorneys take primacy to an extreme, embracing a statistic that has been passed down through the ages that 70-90% of jurors make up their minds about the case after opening statements. In other words, these attorneys go as far as arguing that trial is essentially over after opening statements. Hans and Sweigart[1] offer a rich discussion of this belief in their analysis of civil jurors’ perceptions of attorneys, suggesting that this belief originated with a 1940 study[2] where researchers assessed liability judgments at eighteen different points in a mock trial and concluded that the vast majority of final verdicts were consistent with judgments made right after opening statements.

There is a fair amount of disagreement over the importance of opening statements, despite the lack of published research contradicting it. Hans and Sweigart found 63% of jurors self-reported that they remained neutral until the conclusion of trial. This finding should give some pause, but one must question the efficacy of a study that relies upon self-report, since waiting until the end of trial is the socially appropriate response. Another study found that facts from the last third of trial are most likely to be recalled during deliberations[3], but there is no research linking this saliency to opinion formation. Instead, this finding suggests the last part of trial should focus primarily upon arming advocates to be effective persuaders in deliberations. In other words, if facts from the last third of trial are most cited during deliberations, attorneys should focus on the structure and presentation of issues in this portion of trial to help arm their advocates to effectively advocate during deliberations.

There are two common arguments against the statistic that 70-90% of jurors make up their mind after opening statements. The first stems from mock trial research. Many jury consultants cite anecdotal mock trial experience in which they witness shifts in opinions throughout the course of the presentation of the evidence. It is difficult to discern whether this is the product of the methodological limitations of a mock trial or a genuine contradictory finding. Most mock trials are 1 to 2-day projects, or approximately the same timeframe in which the primacy effect would come into play in an actual trial. In other words, the unanswered question with mock trial research is whether or not the trend of opinion shifting would continue if the mock trial began to resemble the length of an actual trial (i.e. 2-3 weeks). A more applicable jury research comparison would be shadow juries, where 4 to 6 jury-eligible from the trial venue watch the actual trial and provide daily feedback to a jury consultant. While not scientifically-valid due to the small sample size, these projects draw data from the actual trial environment. In my own personal experience, it is rare to see dramatic shifts in the shadow jurors’ opinions over the course of trial following opening statements. Instead, I tend to see shifts in the strength of their opinions. For example, following a strong day for the defense, a plaintiff-leaning shadow juror is more likely to indicate a weaker plaintiff leaning rather than change to a defense leaning. Yet, reversal of opinions is not impossible. It can and has happened.

The second argument against the overarching importance of opening statement is a general refusal to believe the remainder of trial is unimportant, which is the natural conclusion to be drawn from these statistics. Yet this argument relies on a false dichotomy. The pivotal role that opening statements play in opinion formation does not mean that the rest of trial is unimportant. Opinion formation is only one piece of the jury decision-making process. The real burden for attorneys is arming the persuaded to work as effective advocates in deliberations in order to sway other members of the jury and create the majority necessary (assuming state court) to achieve a verdict. Much of this happens following opening statements.

The real debate is over the implications of the statistics about opening statements. If the research shows that 70-90% of jurors make up their minds shortly after opening statements, what does that really mean? Let’s look at a hypothetical to examine this. If we have twelve jurors, let’s assume nine of them (75%) made up their minds after opening statements. Five favor the plaintiff and four favor the defense. In this scenario, the remaining three jurors, who are undecided, may be the most important members of the jury depending on the decision rule. How they swing will significantly impact the dynamic of deliberations and/or potentially create the majority necessary to achieve a final verdict. Perhaps their numbers alone are insufficient to achieve the necessary majority, but their shift alone creates momentum for the side they shift to, which is so critical during deliberations.

There are also frequent situations where a juror forms his or her opinion in a case shortly after opening statements, but then changes that opinion during deliberations. At first glance, this would seem to contradict the idea that his or her opinion was formed shortly after opening statements. But in this situation, it was not anything that happened throughout the remainder of trial that led to the change in opinion. Instead, it was a well-armed advocate on the jury who was able to bring him or her over during deliberations. In this sense, while opinion formation occurred shortly after opening statement and was sustained throughout the course of trial, it ultimately proved inconsequential during deliberations.

In short, early opinion formation is critical at trial and opening statement presents the most important opportunity for it. However, achieving juror leanings in favor of your client at this point in the trial does not guarantee a favorable outcome. There is still much work to be done. In my own experience, which seems to be supported by the general research, opening statements are about establishing your case theory, the case-in-chief for each side is about reinforcing and building upon that case theory, and closing is about arming your advocates to effectively control deliberations. Each part is different, but all are essential ingredients for a favorable verdict.


[1] Valerie P. Hans & Krista Sweigart, “Jurors’ Views of Civil Lawyers: Implications for Courtroom Communication” (1993). Cornell Law Faculty Publications. Paper 321.

[2] H.P. Weld & E.R. Danzig, “A study of the way in which a verdict is reached by a jury.” 53, American Journal of Psychology, 518, (1940).

[3] Kaplan, M. F., & Miller, C. E. Judgments and group discussion: Effect of presentation and memory factors onpolarization. Sociometry, 40 , 337-343, (1977).