After having a few alcoholic beverages, are you able to comprehend your Miranda rights?

U.S. courts often assume that alcohol-intoxicated suspects are capable of understanding the meaning and implications of their Miranda rights (constitutional rights to silence and counsel). This assumption, however, may be unfounded. For starters, sober individuals typically do not understand their rights and the consequences of waiving their rights. Adding alcohol intoxication into the mix may only exacerbate this lack of comprehension. Considering what is known about how alcohol affects cognitive functioning, it is likely that alcohol-intoxicated suspects are at increased risk of failing to comprehend their rights because of their inability to focus and/or think about the future consequences of their actions. Yet, empirical data refuting (or supporting) the court’s assumption that drunk suspects comprehend their rights are lacking, leading researchers Amelia Mindthoff, Jacqueline R. Evans, Andrea C. F. Wolfs, Karina Polanco, Naomi E. S. Goldstein, and Nadja Schreiber Compo to test this assumption in the lab.

As detailed in their article publishedopens in new window in Law and Human Behavior, Mindthoff and colleagues invited college student participants to a simulated bar. While at the “bar,” each participant drank three servings of one of three possible beverage types as dictated by their randomly assigned experimental group: (a) vodka and orange juice (intoxicated group), (b) highly diluted vodka with orange juice (placebo group; participants believed that they were intoxicated), or (c) orange juice (sober group). An experimenter later tested participants’ Miranda comprehension using the Miranda Rights Comprehension Instruments, which consists of validated psychometric measures used to assess Miranda appreciation (recognizing the implications of one’s rights in interrogation and court settings) and understanding (ability to explain Miranda warnings, recognize the correct meaning of the warnings, and define Miranda-related vocabulary).

The researchers’ data did not fully support the court’s assumption that intoxicated suspects fully comprehend their rights. Although participants in the intoxicated group generally understood and appreciated their rights, they scored lower than participants in both the sober and the placebo groups when it came to explaining the meaning of the Miranda warnings (e.g., “you have the right to remain silent,” “you have the right to an attorney”). Intoxicated participants also scored lower than the sober participants in terms of their ability to explain the meaning of Miranda-related vocabulary. Notably, these findings emerged for intoxicated individuals who demonstrated an average .07 breath alcohol concentration—a breath alcohol concentration much lower than has sometimes been seen in court cases in which defendants were considered able to comprehend their rights (e.g., .291).

Based on their initial findings that alcohol intoxication negatively affects some components of Miranda understanding, Mindthoff and colleagues concluded that law enforcement should consider allowing suspects to “sober up” before reading them their Miranda rights at the start of questioning. By doing so, law enforcement may be protecting not only suspects’ rights, but also the validity of statements that suspects make during questioning and the value legal actors and jurors give those statements. The researchers also call for future studies to test how intoxication affects suspects’ decisions to waive their Miranda rights. As data for the effect of alcohol intoxication on Miranda comprehension and waivers accumulates, researchers will be able to make further evidence-based recommendations to law enforcement, legal actors, and the courts.

This article is in the Forensic Psychology topic area. View more articles in the Forensic Psychology topic area.

Mindthoff, A., Evans, J. R., Wolfs, A. C. F., Polanco, K., Goldstein, N. E. S., & Schreiber Compo, N. (2022). The detrimental impact of alcohol intoxication on facets of Miranda comprehension. Law and Human Behavior, 46(4), 264–276. https://doi.org/10.1037/lhb0000490opens in new window

Amelia Mindthoff, PhD, is a postdoctoral scholar at Iowa State University. Her research primarily focuses on examining the efficacy of evidence-based investigative interviewing methods. She also studies juror perceptions and decision making in relation to various topics (e.g., interrogations, forensic evidence).

Jacqueline R. Evans, PhD, is an associate professor of psychology at Florida International University. Her research focuses on the intersection of psychology and the criminal justice system. She is particularly interested in how alcohol intoxication influences the way people interact with the justice system.

Andrea C. F. Wolfs, PhD, is an assistant instructional professor at Chapman University. Her research interests span the psycholegal field, with particular emphasis on investigative interviewing, police practices, and bias.

Karina Polanco is a PhD student at John Jay College of Criminal Justice. Her research focuses on institutional correctional environments, with a specific focus on human rights violations, and how prisons affect mental health and recidivism outcomes. She also investigates criminal and victim psychology as it relates war crimes, human trafficking, and police interrogations.

Naomi E. S. Goldstein, PhD, is a professor of psychology, codirector of the JD/PhD program in law and psychology, and director of the Juvenile Justice Research and Reform Lab at Drexel University. For more than 20 years, Dr. Goldstein has collaborated with community stakeholders to use social science research to improve juvenile justice policy and practice. She uses research to guide large-scale system change, leads implementation projects to promote high-quality dissemination of juvenile justice reforms, and evaluates the effects of new programs and policies on youth and communities.

Nadja Schreiber Compo, PhD, is a professor of psychology at Florida International University. Her research focuses on witness memory and investigative interviewing, including the interviewing of vulnerable victims and witnesses such as people who are intoxicated and youths. She has also been examining which factors increase and decrease bias in investigations.