How reasonable is "reasonable"? A study of U.S. jury instructions

Abstract

In the U.S., juries composed of ordinary citizens make decisions that have profound implications for defendants’ assets, liberty, and even their right to live. To aid the decision process, the judge typically reads oral instructions to the jury. Unfortunately, these instructions abound with linguistic complexities that impede jurors’ understanding and can lead to inconsistent decisions (Charrow & Charrow 1979; Tiersma 1999, i.a.). This dissertation specifically addresses problems with the word “reasonable”. Numerous studies have grappled with “reasonable doubt” (Solan 1999; Dhami et al. 2015; i.a.). This study is unique because it analyzes “reasonable” in a broad range of contexts beyond “reasonable doubt”. To understand the importance of “reasonable" and how juries interpret the word, I utilized empirical, experimental, and theoretical approaches. I used Java to calculate the frequency of “reasonable” in eight codes of jury instructions. I searched through 62,000 lines of instructions and found 2,816 instances of “reasonable”. There are 82 different “reasonable” phrases in the civil instructions, and 42 in the criminal instructions -- suggesting that the interpretational problems span well beyond “reasonable doubt”. The high frequency of “reasonable” underscores the need for jurors to be able to evaluate the word more consistently. I also designed a survey using hypothetical cases and excerpts from actual jury instructions. I surveyed 65 Cornell undergraduates and 70 Cornell Law students. The findings indicated that there were demographic, contextual, and educational effects on participants’ interpretations -- evidence that “reasonable” does not lend itself to consistent interpretation. Finally, I offer a theoretical linguistics account, based on Kratzer 1981/2008. Using insights from this theoretical account and from a pilot study I ran prior to the experiment, I argue for the addition of scales for “reasonable” in jury instructions to help jurors evaluate reasonableness in a comparable way. My research recommends that jurors evaluate reasonableness along particular scales depending on the context: for example, “reasonable cost” might be assessed according to how typical the cost is, whereas “reasonable fear” might be assessed according to the plaintiff’s risk of injury.