Amicus Curiae Briefs

Amicus curiae literally means “friend of the court,” and the author of an amicus curiae brief is an entity who wishes to provide legal, scientific, or technical information to a court to aid its decision. An amicus is not a party to the case entitled to be heard as a matter of right but an individual or an organization granted discretionary leave to file a written brief to provide insight into an issue that the parties to the case may not be able to have because of lack of time, space, or expertise. Amicus curiae briefs have influenced the outcomes of many landmark legal cases. The American Psychological Association (APA) regularly seeks leave to file amicus briefs, as do a host of other individuals and organizations.

Amicus Curiae Briefs Overview

The U.S. adversarial legal system looks to the parties to present the information necessary for the judge or jury to decide the questions presented by a case. The amicus curiae brief is a vehicle for people or organizations, not joined as parties or otherwise entitled to be heard in the case, to provide the judiciary with insights or analysis that would otherwise be lacking in decisions of significant import.

Academic Writing, Editing, Proofreading, And Problem Solving Services

Get 10% OFF with 24START discount code

Amici lack important rights that parties enjoy. For example, amici have no right to settle or refuse to settle claims, to raise a claim or a defense that the parties did not, or even to join a person that the parties did not. There is no constitutional right to file an amicus brief. The opportunity to be heard as an amicus rests with the discretion of the court before whom the case is pending or, in federal court, the consent of the parties or permission of the court. Typically, amicus briefs are thought to address transcendent questions of law decided at the appellate stage of a case. But it is within the discretion of the court to accept an amicus brief at trial as well as on appeal, whether labeled a pure or a mixed question of law or fact.

A Brief History of Amicus Curiae Briefs

Authors such as Simpson and Vasaly have traced the roots of the amicus curiae brief to ancient Rome, where briefs were submitted to provide legal expertise directly to the judiciary at their discretion. Seventeenth-century England provides the first known occurrence of what is now understood as an amicus brief to aid judges in avoiding legal errors and maintaining judicial honor. The first known instance in the United States was when an amicus curiae brief was requested of House Speaker Henry Clay in 1812 by the Supreme Court to aid the Court in the application of law to a land dispute between two states. It was not long after this use of an amicus curiae brief that the practice of filing amicus briefs in appellate courts began in earnest. Although the core purpose of the amicus curiae brief has always been a non-partisan effort to educate the court and not to advance the interests of a specific party, there has always been a tension between these motivations.

The amicus curiae brief may seek to serve numerous functions categorized by Simpson, include the following: (a) to address issues of policy; (b) to provide a more appealing advocate; (c) to support the granting of a Supreme Court review; (d) to supplement the brief of a party; (e) to give a historical perspective; (f) to provide technical or scientific aid; (g) to endorse a particular party in the case; and (h) to try and correct, limit, publish, or “depublish” an issued judicial opinion. These functions are not mutually exclusive; thus an amicus curiae brief may serve multiple purposes.

Prevalence and influence of the Amicus Curiae Brief

The prevalence of amicus curiae briefs submitted to the courts, and the Supreme Court in particular, has increased over time. During the first few decades of the 20th century, Kearney and Merrill found that amicus curiae briefs were only filed in approximately 10% of the Supreme Court’s cases. This practice has increased dramatically. For example, in the most recent decades, at least one amicus curiae brief has been filed in at least 85% of the Court’s cases that incorporated oral arguments. Thus, today, cases with no amicus curiae filings have become the anomaly.

As the number of amicus curiae briefs filed has increased over time, so has the ability of the amicus curiae brief to influence the outcome of court cases, especially where there are many amicus curiae briefs that aid the parties in strong calls for change in the areas of social policy. Amicus curiae briefs that focus on social policy instead of pure legal argument have come to be known as “Brandeis briefs,” named for the first filing by Louis Brandeis, later appointed a Supreme Court justice. Brandeis’s use of a nonlegally oriented brief to highlight social science data has become a model for presenting such information.

Perceptions of the Amicus Curiae Brief

Perceptions of the use and utility of amicus curiae briefs vary widely within the legal profession. From one point of view, the amicus curiae brief is a beneficial vehicle, providing arguments, technical information, or authorities not included by the parties. Those agreeing with this view point to the numerous references to amicus curiae briefs in many court opinions to suggest that courts find amicus curiae briefs helpful.

Some members of the legal community hold an opposite view. Many judges report that amicus curiae briefs replay the arguments put forth by the parties and provide the court little or no assistance. Those who subscribe to this view contend that amicus curiae briefs are a nuisance, burdening judges and their staffs yet providing few, if any, benefits. For those who view the amicus curiae brief in this way, either prohibiting or limiting the submission of amicus curiae briefs would improve the judicial system.

Finally, a middle ground regarding the amicus curiae brief acknowledges its prevalence and its potential utility but cautions that amicus curiae briefs are most often filed by large, resourceful organizations. While amicus curiae briefs may prove helpful, researchers including Kearney and Merrill caution that inequality in organizational power, interest, and influence should be considered when contemplating an amicus curiae brief.

The APA as a Friend of the Court

The APA has been a prolific author of amicus curiae briefs. It has submitted amicus curiae briefs in cases presenting issues that can potentially affect the internal practices of the APA or its membership as well as external issues of social import that may affect the welfare of populations served by the APA. The topics of APA amicus briefs cover a wide gamut, ranging from scientific research and testing, psychological practice, and treatment of the mentally ill to abortion, sexual orientation, affirmative action, and the death penalty. While the wide range of amicus curiae brief topics are as diverse as the United States itself, in each specific case, the APA perceived either an important social value or an internal necessity in speaking as a “friend of the court.”

The APA offers full-text copies of numerous amicus curiae briefs on its Web site, including briefs submitted in “landmark” cases. As an example, in Planned Parenthood of Southeastern Pennsylvania v. Casey (1992), the APA presented amicus briefs containing extensive psychological research to assist the Supreme Court’s scrutiny of a Pennsylvania law requiring married women to obtain consent from their husbands before obtaining an abortion. The APA’s amicus brief presented research that such a restriction supplants a woman’s rational choice and places an unfair and potentially harmful burden on women who have compelling reasons not to inform their husbands of their choice. The Supreme Court found that the Pennsylvania law placed an unacceptable burden on women and declared the law unconstitutional.

In the Court’s 2005 decision in Roper v. Simmons, which presented the constitutionality of imposing the death penalty on someone who was under 18 when the murder was committed, the APA presented research on juvenile behavior, maturity, decision-making ability, and criminology. In a 5:4 decision, in which the research presented by APA was central, the Supreme Court held that the Eighth Amendment of the Constitution prohibits the imposition of the death penalty on juveniles under the age of 18 when the crime was committed.


  1. Barrett, G. V., & Morris, S. B. (1993). The American Psychological Association’s amicus curiae brief in Price Waterhouse v. Hopkins: The values of science versus the values of the law. Law and Human Behavior, 17, 201-215.
  2. Ennis, B. J. (1984). Symposium on Supreme Court advocacy: Effective amicus briefs. Catholic University Law Review, 33,
  3. Fiske, S. T., Bersoff, D. N., Borgida, E., Deaux, K., & Heilman, M. E. (1991). Social science research on trial: Use of sex stereotyping research in Price Waterhouse v. Hopkins. American Psychologist, 46, 1049-1060.
  4. Kearney, J. D., & Merrill, T. W. (2000). The influence of amicus curiae briefs on the Supreme Court. University of Pennsylvania Law Review, 148,
  5. Krislov, S. (1963). The amicus curiae brief: From friendship to advocacy. Yale Law Journal, 72,
  6. Planned Parenthood of Southeastern Pennsylvania. v. Casey, 505 U.S. 833 (1992).
  7. PsycLAW: APA’s amicus briefs. (n.d.). Retrieved June 24, 2015, from
  8. Roper v. Simmons, 543 U.S. 551 (2005).
  9. Simpson, R. W., & Vasaly, M. R. (2004). The amicus brief: How to be a good friend of the court (2nd ed.). Chicago: American Bar Association.
  10. Walbot, S. H., & Lang, J. H. (2003). Amicus briefs: Friend or foe of Florida courts? Stetson Law Review, 32.

Return to the overview of Trial Consulting in Forensic Psychology.