Fake Video Can Convince Witnesses to Give False Testimony

People believe what they see, and they’re willing to punish each other for it — apparently even when what they’re seeing is a fake video that doesn’t jibe with real-life experience.

Psychologists have long known that our memories of past events can be influenced by misleading information, but now they’ve proven that doctored video evidence can convince people to offer false eyewitness testimony. In a study of 60 college students performing a computerized gambling task, nearly half were willing to testify that they saw their partner cheat in real life after watching fabricated video evidence. Of students who were told that video evidence existed but didn’t watch the footage themselves, only 10 percent gave false testimony. [...]

In the study, each student was paired with a member of the research team disguised as another participant. The pair sat side-by-side and played a computerized gambling game, which involved betting fake money based on the likelihood of answering a multiple choice question correctly. Each person was in charge of keeping track of their own wins; when a subject correctly answered a question, they got to take money from a shared “bank,” and when they incorrectly answered a question, they had to put money back. Participants were told that at the end of the game, the person who made the most money would win a prize.

After the gambling concluded, the researchers used Final Cut Pro to alter a video recording of the game and make it look like the partner had cheated. Five to seven hours after the first task, students were called back to the lab and told that their absent partner was suspected of cheating. One-third of the students were also told that the researchers had video evidence of the cheating, and another one-third got to watch the doctored video themselves.

Before asking participants to sign an eyewitness testimony, the researchers emphasized that no one should testify unless they were 100 percent sure they had seen their partner cheat, and they emphasized that the cheater would be punished. Students who watched the fake video were far more likely to give false testimony than students who heard about the video or were simply told that their partner was suspected of cheating.

Fake Video Can Convince Witnesses to Give False Testimony