By Dr. Ken Broda-Bahm:
It should have been big victory for social science in the courtroom: Noting that lay jurors tend to give eyewitness testimony in criminal cases far more weight than it deserves, psychological researchers weighed in with recommendations, and remarkably, judges actually listened. In July of 2012, New Jersey's judiciary adopted new jury instructions that sought to educate jurors on the problems of human memory in the context of eyewitness identification. The new instructions were designed to function as a kind of tutorial on how to use and to value the testimony without exaggerating its veracity. Specifically, the expanded instructions aimed at disabusing jurors of the notion that memory is "like a video recording," emphasizing that police identification procedures can be intentionally or unintentionally misleading, and spelling out a variety of factors that affect the ability to see and to remember that should be factored in. In addition, the instructions stressed that "a witness's level of confidence, standing alone, may not indicate the reliability of the identification."
This, of course, was applauded by those who have studied the problem of eyewitness identification and false convictions, with Innocence Project Director Barry Scheck predicting that "these instructions will revolutionize the way that juries scrutinize identification evidence." The problem is, according to one of the first investigations to test whether it works, it doesn't. Or, at least, not quite. A team of University of Arizona researchers (Papailiou, Yokum, & Robertson, 2015) exposed mock jurors to a video-recorded reconstruction of a murder trial involving what the instructions would consider either strong or weak eyewitness testimony, and then participants heard either the standard instructions in common use throughout the states or the new and improved New Jersey instructions. Mock jurors were less likely to convict on the basis of eyewitness testimony after receiving the instruction, but were not more sensitive to quality. "The New Jersey instruction," the researchers concluded, "did not improve jurors' ability to discern quality; rather, jurors receiving those instructions indiscriminately discounted 'weak' and 'strong' testimony in equal measure." So the instructions seemed to be effective in highlighting the issue, but not entirely effective in correcting the problem. In this post, I will take a look at the research, noting some implications for all instructions, not just the eyewitness instructions.