“Implicit bias” refers to bias which results from the automatic functioning of the brain. It includes attitudes or stereotypes that affect peoples’ understanding, decision-making, and behavior, without the people being conscious of their operation.


Human brains need to make thousands of decisions each day. Brains utilize mental shortcuts for handling many of those decisions. They do this by developing mental maps or schema so that they can process information automatically. Most perceptions are implicit, meaning that our brains process most of the work to be done daily, using schema rather than a full deliberative process. Our brains use schemas for various daily functions, including to classify people.


Brain science has shown that many attitudes and stereotypes can affect the brain’s automatic functioning, which means the brains’ owners are unaware that those attitudes and stereotypes are being used in their decision-making. In other words, as a person interacts with other people, their brains are using attitudes and stereotypes in the processing of those interactions. In this context, an attitude is an association between some concept (in this case a social group) and evaluative feelings that are positive or negative. A stereotype is an association between a concept (here, a social group) and particular traits.


Mind scientists have increasingly developed tools to demonstrate that implicit bias exists in the auto-pilot processing by the brain. Harvard’s Implicit Association Test (IAT) uses reaction time differences between two types of tasks to show what attitudes and stereotypes affect an individual’s brain processing. The IAT is able to compare reaction time between when schema-consistent pairings are used versus when schema-inconsistent pairings are matched. Millions of people have taken various forms of the IAT, and the test may be accessed online at https://implicit.harvard.edu/implicit/takeatest.html by any interested individual.

Implicit bias differs from explicit bias because in explicit bias the person is conscious that they are using biased attitudes and stereotypes in their decision-making, and they endorse their own biases. Explicit biases against certain categories of people have been regulated by the U.S. Constitution, many non-discrimination statutes, and through contracts, particularly collective bargaining agreements. The United States Supreme Court has long “recognized that whether the trial is criminal or civil, potential jurors, as well as litigants, have an equal protection right to jury selection procedures that are free from state-sponsored group stereotypes rooted in, and reflective of, historical prejudice.







3 “Implicit Bias in the Courtroom” [Doc. 240]

4 Jerry Kang, “Implicit Bias a Primer for Courts,” prepared for the National Campaign to Ensure the Racial and Ethnic Fairness of America’s State Courts, August 2009. [Doc. 270]

5 “Implicit Bias in the Courtroom”, at 1129-1130. [Doc. 240] See also Jerry Kang at pps. 1, 7-8. [Doc. 270]

6 More information about the IAT is available at https://implicit.harvard.edu/implicit/iatdetails.html [Doc. 200]

7 “Implicit Bias in the Courtroom”, at 1132. [Doc. 240]

8 J.E.B. v. Alabama ex rel T.B., 511 U.S. 127, 128 (1994) (purposeful racial discrimination in trial proceedings requires new trial) [Doc. 280]; Smithkline Beecham Corporation v. Abbott Laboratories, 740 F.3d 471 (9th Cir., 2014) (purposeful sexual orientation discrimination in trial proceedings requires new trial). [Doc. 290]