By Dr. Ken Broda-Bahm:
Lawyers like to be efficient in communication, particularly in the setting of litigation, bound as it is by time and relevance. Perspicuity when persuading is considered a virtue in that setting and “Don’t do what isn’t necessary” is generally a good rule to follow. But on the subject of graphics, don’t carry that rule too far. Take, for example, the idea of using a chart or a graph in order to illustrate some kind of numerical relationship. If the question is, “Do I really need this?” the answer could be, “No – these jurors are literate and can understand the idea of a ‘15 percent increase’ without me showing it to them.” But don’t forsake the graphics too quickly. A recent study confirms the intuition that “seeing is believing,” even where what is seen carries only a trivial difference from what is described. Just using a chart substantially increases persuasive effect, according to a recent study by two Cornell researchers, (Wansink & Tal, 2014). Comparing the effectiveness of a simple text to the effectiveness of that same text with a basic chart, the study found that adding the simple graph increased beliefs about a medicine’s effectiveness from 68 percent to 97 percent. “But here’s the kicker,” the New York Times reported, “That chart contained no new information; it simply repeated the information in the orginal vignette.”
According to the study, the improved persuasiveness came not from additional data or reasons, or from improved compehension, but instead simply came from a positive association with science. “Even trivial elements can increase public persuasion despite their not truly indicating scientific expertise or objective support,” the study authors concluded. Adding a chart doesn’t make the claim any more scientific, but the visual data primes the audience toward that mode of thinking. As a result, they’re more persuaded by the data. The implication of this for courtroom persuasion is clear: Litigators should always lean toward visualizing any data that they talk about – not just the complex data, but all data. The question should never be, “Can they understand the point without the graphics?” but should instead be, “Can we simply show it as well as tell it?” This post takes a look at the research, and suggests a few less common ways that graphics can be used to consistently illustrate arguments in court.