Cognitive Psychology and Law (Dan Reisberg, ch. 1)

Research in cognitive psychology can help us understand deep theoretical issues, such as what it means to be rational, or what the function of consciousness might be. But our research also has pragmatic implications, with our studies often providing important lessons for how we should live our day-to-day lives. Some of those pragmatic lessons are obvious. For example, students can use what we know about learning and memory to choose effective study strategies. Some implications of our work, though, are less obvious-for example, the implications of cognitive psychology for the criminal-justice system.

How is our science relevant to police work or the courts? To answer this question, think about what happens in a criminal investigation: Eyewitnesses provide evidence, based on what they paid attention to during a crime and what they remember. Police officers question the witnesses, trying to maximize what each witness recalls, but without leading the witness in any way. Then the police try to deduce, from the evidence, who the culprit was. During the trial, jurors must listen to evidence and make a judgment about the defendant's innocence or guilt.

Cast in these terms, it should be obvious that our understanding of attention, memory, reasoning, and judgment (to name just a few processes) are directly relevant to what happens in the legal system. Indeed, we can plausibly hope to use what we know about these processes to improve the courts' procedures-for example, to design more effective ways to question witnesses (memory), to help jurors do their job (judgment), and so on.

Drawing on these points, we will provide a supplemental essay for every chapter of the textbook, describing how the materials in that chapter can help us understand a specific aspect of the criminal justice system. These essays will illustrate how cognitive psychology can be brought to bear on issues of enormous importance, issues that are in obvious ways rather distant from the laboratory. At the same time, these essays are designed to deepen the students' understanding of cognitive psychology through an examination of some of our field's practical applications.

Let's add, though, that other essays could highlight cognitive psychology's contributions to other real-world concerns. Why, therefore, should we focus on the criminal-justice system? There are several reasons, but one prominent motivation is my own involvement with these issues: As a psychologist specializing in memory, I often consult with the police and the courts on questions about eyewitness evidence. This work allows me, as a scientist, to play a small part in improving the criminal-justice system in the state of Oregon. The work also provides a frequent reminder for me that our science does know things that really are important, useful, and sometimes surprising. I therefore find this work with the courts to be intellectually, politically, and personally exciting, and hope you, as a reader, can share some of that excitement.