Most people enjoy a good magic trick, but these sleights of hand may prove to be more than just entertainment. Consider the results of a recent study.
In one experiment, 420 people were shown three short video clips, none of which had sound. In the first video, a young man performs a simple trick where he breaks a crayon in half, squeezes it in one hand and appears to make the crayon whole again. A second video shows him performing silly tricks – with either a crayon or a coin – that have no element of magic to them. It is the third trick that shows how faulty our perception can truly be.
In the third video, the magician goes through the motions of a disappearing object trick, but is not actually holding an object to begin with. After viewing, participants were asked to describe what was shown in the video. Of the 420 participants who watched the video, nearly one-third (32 percent) claimed that they saw “something” disappear.
If you watch the videos, which can be seen here, it is fairly easy to see that the third “trick” never involved a physical object. Yet a significant portion of viewers remembered seeing something; probably because they had expected to see something.
Human perception is far from perfect, and human memory is even less reliable. This isn’t problematic in and of itself. But when we treat memory and perception as though they are infallible, that is a problem.
Until recently, eyewitness testimony was highly influential in criminal cases. It could even result in convictions when there was no other evidence to corroborate what the witness said they saw. Now, criminal justice reform advocates are pushing for measures that would reduce the use of eyewitness testimony, or at least inform jurors that it may not be as accurate as once thought.
If we want our criminal justice system to truly be just, we must continue to be guided by science and reason in the courtroom. And to that end, we must be willing to understand and accept the limits of human perception and memory.
