Dateline: November, 2010, Issue 4 [rev. 10/21]
Jury instructions are designed to instruct jurors in the law, and the law generally assumes complete or near-complete juror comprehension of instructions.
Considerable social science research has examined how well jurors understand jury instructions.
In a review of this research literature, Elwork and Sales (1985) report that comprehension levels for pattern jury instructions stand at about 50% or less.
Rogers (2021) summarizes studies reporting comprehension rates ranging from 15% on the low end to around 70% in the highest estimates, with most studies reporting accuracy rates nearer to 50%. Reported levels of post-instruction comprehension also often are no better than chance, and jurors possess only modest (if any) improvement in understanding the law as compared to people who have not been instructed.
The average juror has a low level of understanding of jury instructions. Instructions do not increase significantly jurors' understanding of the law.
Source Elwork, A., & Sales, B. D. (1985). Jury instructions. In S. M. Kassin & L.S. Wrightsman (eds.), The psychology of evidence and trial procedure (pp. 280-297). Beverly Hills, CA: Sage.
Source Rogers, M. (2021). Laypeople as learners: Applying educational principles to improve juror comprehension of instructions. Northwestern University Law Review, 115(4), pp.1185-1225.