The problem with eyewitness testimony
By More on the legal process in the killing of Michael Brown.
A host of psychological factors make eyewitness testimony far from reliable. . .The easiest way to sum up those factors is this: People are as a general matter actually quite bad at recalling accurately what they’ve witnessed, and, worse yet, they (we) tend to have great confidence in our ability to recall events accurately. More perversely still, people attempting to judge the credibility of eyewitnesses put great stock in the level of confidence a witness displays in regard to the accuracy of the witness’s recall, even though experimental psychology has demonstrated that there is no correlation between such confidence and accurate recall.
Many other factors conspire to make eyewitness testimony unreliable: confirmation bias leads us to see what we expect to see, even if it isn’t actually there, while misinformation effects produce false memories of things that never happened. A famous example of the latter is a Dutch psychology experiment in which more than half of the subjects recalled seeing film footage of an airliner crashing into a building, after researchers referenced the footage in interviews with the subjects. Although the plane crash was a real event that the subjects all recalled vividly, no footage of the crash ever existed.
In another famous experiment, subjects were asked to count the number of passes made by two basketball teams wearing different colored jerseys. In the midst of the game, a man in a gorilla suit walked slowly across the court. When asked afterward if they had noticed anything unusual during the game, nearly half of the subjects didn’t recall anything noteworthy. Such experiments illustrate our tendency to miss even the most obvious evidence when we are under various kinds of cognitive stress.