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John S. Shaw III, assistant professor of psychology at Lafayette, will speak on his research into “Eyewitness Confidence in the Courtroom” at 4:10 p.m. Monday, Oct. 23, in the auditorium of Kirby Hall of Civil Rights. Free and open to the public, the talk is sponsored by Lafayette’s Academic Research Committee (ARC).
The talk is one of six ARC faculty presentations this school year. Remaining forums will feature Curlee Raven Holton, associate professor of art and director of the Experimental Printmaking Institute; Scott Moor, assistant professor of chemical engineering; William D. Jemison, assistant professor of electrical and computer engineering; and James DeVault, associate professor of economics and business.
Shaw says, “The general public, members of the legal profession, and even the courts all consider eyewitness confidence to be a reliable indicator of eyewitness accuracy. In addition, trial-simulation studies have shown that jurors accord a great deal of weight to eyewitness confidence. Yet, most of the experimental evidence suggests that the relationship between witness confidence and accuracy is generally too small and unreliable to be forensically useful.
“One reason that eyewitness confidence and accuracy are so poorly associated is that some factors may affect eyewitness confidence independently of eyewitness accuracy,” Shaw continues. “Very few studies have tested the malleability of eyewitness confidence directly. My research program examines this issue from a variety of perspectives.”
In Shaw’s dissertation and several follow-up studies, he has found that a common police investigation procedure — repeated questioning of witnesses — can lead to increases in witnesses’ confidence in their testimony without any corresponding changes in witness accuracy. In the past several years, Shaw has published several papers on the effects of post-event misinformation on eyewitness confidence and accuracy. A series of his studies demonstrated that witness questioning in one language after an event can alter later memory reports given in a second language. In another study on eyewitness memory, he and fellow researchers found that exposing a witness to information about what a co-witness has said can change that witness’s later recollection of an event. Shaw also collaborated with a team of researchers in an examination of the biasing effects of the type of suggestive questioning that was used by social workers who interviewed child witnesses in the McMartin Preschool molestation case.
More recently, Shaw has examined lay perceptions of eyewitness accuracy and confidence.
“In a series of surveys, my colleagues and I asked lay people to indicate what factors they thought were most important in determining the accuracy of an eyewitness’s testimony,” he says. “One of our most interesting findings was that lay people place a great deal of importance on a set of factors referred to in the literature as ‘estimator variables’ — meaning those variables over which the legal system has no control. Examples of estimator variables are the age of the witness and whether the witness was wearing glasses at the time of the event. In contrast, most of the psychological research is on system variables, which are variables over which the legal system does have control. System variables include the types of questions that police ask witnesses and the composition of lineups.”
One of Shaw’s current projects involves an examination of the relationships among eyewitness confidence, eyewitness accuracy, and response time. “As expected, I have found response time to be negatively correlated with confidence,” he notes. “Furthermore, the relationship between response time and confidence can be altered by a variety of factors, including instructions given to the participant-witnesses during the final memory test (e.g., emphasize speed vs. emphasize accuracy).”
Shaw holds a Ph.D. from the University of California, Los Angeles, and a J.D. from Stanford Law School. After graduating from law school in 1980, he practiced criminal law as a prosecutor and public defender for nine years. He draws on this experience in both his teaching and research. Shaw is a social psychologist, and his primary research interests include eyewitness memory, eyewitness confidence, and attitudes about genetic testing.
Geared for a broad audience, ARC forum talks are less technical than presentation that would be given at a professional meeting. They last 20 to 30 minutes and are followed by a question-and-answer and discussion session.
“The idea behind the research forum is to allow the college community to learn what research is like in different fields and the interests of various faculty,” says Jeff Bader, associate provost and director of research services. There are three presentations in each semester. The fields rotate so at least one presenter year represents each of the four academic divisions: humanities, social sciences, natural sciences, and engineering.