In a world where anyone can edit a movie and stick it up on YouTube, can we still trust video evidence of a crime? Research from the University of Warwick suggests maybe not. By altering video footage, Kimberley Wade and colleagues were able to convince people they witnessed an event that never actually occurred.
In a study published today in Applied Cognitive Psychology, Wade’s team asked sixty university students to play a computerised gambling game. Each participant thought they were playing with another student, but they were actually paired with a member of the research team. Betting on the answers to multiple choice questions, they either took money from a shared pool for a correct answer, or returned it following a wrong answer. These were clearly marked with a green tick and a red cross.
After the game, the footage was doctored to turn a correct answers in to an incorrect one, making the research team member appear to be cheating. The participants were split in to three groups; one group were shown this doctored footage, another were told that their partner had been caught cheating on camera, and the third were simply informed about the cheater. All groups were then asked to sign a statement affirming that they had seen cheating take place.
Nearly 40% of those that watched the video agreed to sign, despite the fact they were confirming an incident that had not taken place. Another 10% signed after being asked a second time. This compares to 10% of those who were told about the film, but not shown it, and 5% who were just informed about the cheating.
The researchers conclude their paper with a warning against the potential for edited footage to result in miscarriages of justice, even outside the courtroom. Their research shows that witnesses shown fabricated evidence before a hearing could end up changing their story, and testifying about events that never happened.
Wade, K., Green, S., & Nash, R. (2009). Can fabricated evidence induce false eyewitness testimony? Applied Cognitive Psychology DOI: 10.1002/acp.1607