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Friday, September 29, 2023

The meaning of ‘reasonable’: Evidence from a corpus-linguistic study

Lucien Baumgartner & Markus Kneer
In Kevin P. Tobia (ed.), The Cambridge 
Handbook of Experimental Jurisprudence. 
Cambridge University Press (forthcoming)


The reasonable person standard is key to both Criminal Law and Torts. What does and does not count as reasonable behavior and decision-making is frequently determined by lay jurors. Hence, laypeople’s understanding of the term must be considered, especially whether they use it predominately in an evaluative fashion. In this corpus study based on supervised machine learning models, we investigate whether laypeople use the expression ‘reasonable’ mainly as a descriptive, an evaluative, or merely a value-associated term. We find that ‘reasonable’ is predicted to be an evaluative term in the majority of cases. This supports prescriptive accounts, and challenges descriptive and hybrid accounts of the term—at least given the way we operationalize the latter. Interestingly, other expressions often used interchangeably in jury instructions (e.g. ‘careful,’ ‘ordinary,’ ‘prudent,’ etc), however, are predicted to be descriptive. This indicates a discrepancy between the intended use of the term ‘reasonable’ and the understanding lay jurors might bring into the court room.

From the Discussion section

Our research reports an intriguing discovery: the expression ‘reasonable’ is most often not just a straightforward descriptive term. In fact, only 17.18% of uses in our sample fall into this category.  Interestingly, other words that are commonly used to elucidate ‘reasonable’ in jury instructions, like ‘average,’ ‘ordinary,’ ‘rational,’ and ‘prudent’ are primarily descriptive. In terms of multidimensional proximity, ‘reasonable’ inhabits a very different part of the space. Considering that these terms are used somewhat interchangeably in jury instructions, our data suggests that jurors enter the courtroom with a different concept than the one intended or expected by legislators. However, it is important to keep in mind that we are not directly comparing the language of laypeople and experts and therefore cannot make direct inferences about possible differences between the two. And yet, judging from the fact that laypeople use ‘reasonable’ in a completely different way than other terms used to characterize ‘reasonable’ in the jury instructions, this suggests, at least indirectly, a certain discrepancy in language use. Furthermore, our results align with the findings by Willemsen et al. (2023) that laypeople tend to use certain terms in a more evaluative manner, compared to legal professionals—at least if the jury instructions are used as a proxy thereof. This disparity in understanding can have significant ramifications during trial, as jurors and legal professionals may not be on the same page. For a more comprehensive investigation of this discrepancy, further comparative studies are required.

My quick summary:

The authors argue that beliefs surrounding reasonableness has implications for the law. They suggest that the reasonable person standard should be interpreted as an evaluative standard, rather than a descriptive one. This would mean that jurors would be more likely to consider the social and cultural context when making their judgments about what is reasonable.

The authors also found that other terms that are often used interchangeably with "reasonable" in jury instructions, such as "careful" and "prudent," are more likely to be used in a descriptive sense. This suggests that there is a discrepancy between the way the law intends these terms to be used and the way lay jurors might understand them.

The article concludes by calling for more research on the meaning of "reasonable" in the context of the law. The authors argue that this research could help to improve the fairness and accuracy of the legal system.