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In Doubt: The Psychology of the Criminal Justice Process (Dan Simon)USC Gould School of Law
Harvard University PressUSC Gould School of Law
Harvard University PressHarvard University Press

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Book Review (96 Judicature 45, July-August 2012)

Toward a more people-centered system of justice: a new framework for examining wrongful convictions
by Gary L. Wells
96 Judicature 45 (July-August 2012)

In Doubt: The Psychology of the Criminal Justice Process, by Dan Simon. Harvard University Press, 2012. 416 pp.

Judicature CoverThe other day I cleared my desk of a stack of recent books on convictions of the innocent. The stack had reached the point that I feared even the slightest bump might send the books tumbling down on an innocent visitor. So the books went onto the shelves, joining a trove of such books published in recent years with titles such as Convicting of the Innocent, Wrongful Conviction, False Justice, and others. Yet even among this plethora of titles, one stood out: Dan Simon's In Doubt: The Psychology of the Criminal Justice Process.

Like most of the other books in this genre, In Doubt makes some use of actual cases of exoneration (e.g., DNA-based exonerations of Ronald Cotton, Kirk Bloodsworth, and others) to bring home the reality that innocent people are convicted and to concretely illustrate key points, such as the way that one inculpating piece of evidence can make the entire set of evidence appear inculpating or how investigators prematurely stop looking for more evidence after finding what seems to be support for the leading hypothesis. But Simon's book also stands out from the others in an important way: it comes much closer to articulating a conceptual framework, drawing together what might otherwise be thought of as a series of somewhat unrelated observations about problems that lead to convictions of the innocent. This conceptual framework revolves largely around the idea that "Criminal verdicts can be no better than the combined result of mental operations of the people involved in the process" (p.2). The result is a beautiful yet powerful treatise on how social and cognitive science can explain processes that lead to wrongful conviction-as well as ways to solve this pressing problem.

A professor of Law and Psychology at the University of Southern California, Simon earned his LLB from Tel Aviv University and an MBA from INSEAD in France. He was an attorney for the Association for Civil Rights in Israel, where he worked on civil rights for Palestinians in the West Bank and delivered arguments before the Israeli Supreme Court. He earned his SJD (Doctor of Judicial Science) from Harvard University in 1997 and has been on the law faculty at USC since 1999. In addition to his illustrious legal background, Simon has made substantial contributions to cognitive and experimental social psychology with his theoretical and empirical work on cognitive consistency, decision making, and cognitive coherence: on top of publishing law review articles, he has also managed to publish experimental studies in esteemed peer-reviewed journals, including Psychological Science, the Journal of Personality and Social Psychology, and the Journal of Experimental Psychology: General. It is within his well-honed experimental and theoretical framework (especially his conceptualization of "cognitive coherence") that Simon draws his insights and weaves together a unique and worthy treatment of the problem of errors in the criminal justice system.

In the book's eight relatively short chapters, Simon covers a lot of ground, ranging from the cognitive dynamics of investigation to human memory errors, problems in interrogation, and the manifestation of problems in the courtroom, yet the pages go by quickly due to his insightful and effective prose. From the perspective of scholars, the real meat is in the 161 pages of endnotes that involve extensive citations to back up nearly every observation contained in the text. The vast majority of these citations are to original peer-reviewed articles published on cognitive psychology, social psychology, and decision making. Altogether, there are 1,428 footnotes containing citations and commentary.

Following the introductory chapter, which covers both what will be discussed as well as mentions some of the areas not covered (e.g., the book does not examine plea bargaining), the book is divided roughly into three parts. The first part (chapters 2-5) deals with the investigatory phase. Simon notes that the criminal justice process cannot be any better than the "evidence on which it feeds." Hence, chapter 2 revolves around police investigators and discusses cognitive factors such as abductive reasoning and the confirmation bias, and motivational factors such as group membership and emotion. It is here that he introduces the concept of the coherence effect, in which "facts guide choice of the preferred conclusion, [and then] the emergence of that conclusion radiates backward and reshapes the facts to become more coherent with it" (p. 34). For example, an eyewitness might give an account that agrees with investigators' theory of a case and, in turn, the investigators might then shape other facts (e.g., poor lighting) to cohere (the street lamp must have been burning brightly that night). This chapter, as with all chapters in the book, ends with recommendations for reform, such as that there be full recordings of the investigatory process. Chapter 3 deals with eyewitness identification, chapter 4 with event memory, and chapter 5 with interrogation of suspects. These are timely topics; much has been written in recent years about problems with eyewitness memory and about interrogations leading to false confessions, and these chapters are well crafted to draw parallels to other themes in the book. including the coherence effect as well as the confirmation bias; the inclination to notice and favorably interpret evidence consistent with one's prior beliefs, as well as not notice and negatively interpret evidence inconsistent with those beliefs.

The second part of the book deals with the adjudicatory phase. Simon describes the problem in the adjudicatory phase as being a task in which there are multiple inputs from sources of unknown validity and compromised quality that somehow have to be integrated to reach a binary conclusion (ie., an either/or conclusion). He notes how original evidence is degraded, contaminated, and synthesized before a judge or jury hears it. Personally, I have often noted that eyewitness identification testimony, which I have studied for over 35 years, is a lot like the old saying about making sausage: The product may look and taste just fine, but if you actually knew the process that goes into making it, you would be much less likely to buy it. Chapter 6 parallels the earlier chapters by focusing on how judges and juries process eyewitness testimony evidence, confession evidence and alibi testimony, and how they make judgments on deceitful testimony. Complicating these matters are courtroom persuasion tactics, stereotypes, and yes, once again, the coherence effect. Chapter 7 examines the ability of a number of fact-finding mechanisms that the legal system has created to serve as safeguards. These include cross examination, jury instructions, standard of proof criteria, jury deliberation, and appellate and post-conviction review. While conceding that these safeguards do promote diagnostic accuracy to some extent, an argument could also be made that there are many circumstances in which they have mixed effects, are ineffective, and are even detrimental. Again, recommendations for reform are made that are well reasoned and well grounded. For example, Simon, recommends that jury instructions be provided in writing rather than merely spoken and that when trial judges are asked to clarify jury instructions the jurors should be provided with helpful explanations rather than merely repeating the instructions.

The book's final chapter, titled "Toward Accuracy," is at once a summary of its main points and a major argument in and of itself. Particularly interesting to me is Simon's discussion of what he calls "the marginalization of accuracy." He notes "One of the most bewildering and underappreciated features of the criminal justice process is the low value it assigns to the accuracy of its factual determinations," and goes on to explain:

"It would be naive to suggest that determining facts is the single desideratum of the criminal justice system. The process must fulfill a broader array of objectives, which include promoting the public's acceptance of verdicts, expressing society's values, asserting the authoritative power of the state, bringing closure to victims, and finalizing disputes... [Moreover] Defendants are promised procedural rights, not reliable evidence or accurate verdicts." (page 209)

Simon believes strongly that these other objectives cannot be properly attained when accuracy is marginalized: "Achieving the system's competing objectives-the public's acceptance of the verdict, the assertion of the state's authority, and the expression of society's values-cannot be done conscientiously without... a system that is seriously committed to the accuracy of its verdicts." (pp. 216-217).

As I finished the last chapter of In Doubt, I began to think about the similarities between the design of better machines and the design of a better justice system: there have been great successes in the last 20 years in the design and development of better machines, from airline cockpits to cell phones, that are based on an understanding of how people perceive, think, reason, and remember. Among other things, human-oriented designs serve to mitigate common cognitive errors that occur in human-machine interactions. In Doubt is an outstanding contribution to the core literature on wrongful convictions because it rests on a fundamentally similar premise: The design of a properly-functioning legal system requires an understanding of the mental processes and limitations of the people involved. Coming to grips with mental limitations and cognitive biases can lead to a better justice system, one designed with people in mind.

Gary L. Wells is Distinguished Professor of Psychology and the Wendy and Mark Stavish Chair in Social Sciences at Iowa State University. He also serves as Director of Social Sciences for the American Judicature Society's Center for Forensic Science and Public Policy. (

Reprinted with permission of the American Judicature Society.