Misinformation effect
Information heard after an event, such as the wording of a question, can change what people remember about the event itself.
Memory is not a recording. Each time we recall something, the brain rebuilds it from fragments, and anything we learn afterwards can slip into the rebuilt version. This is the misinformation effect.
The classic demonstration came in 1974. Elizabeth Loftus and John Palmer showed students a film of a car crash and asked how fast the cars were going when they 'smashed' into each other, or 'hit', 'bumped', 'collided' or 'contacted'. 'Smashed' gave an average of about 41 miles per hour, 'contacted' about 32. A week later, 32% of the 'smashed' group said they had seen broken glass, against 14% of the 'hit' group. There was no broken glass in the film.
That is why police and courts now try to avoid leading questions: a witness who is honestly trying to remember can still report something they never saw.
A common misconception is that confident memories are accurate ones. Confidence and accuracy are only loosely linked, especially when a memory has been retold many times.
See it in action
Coming up in future stories
- Did the Dogon Know Sirius Had a Hidden Twin? 1931–1991 · Bandiagara, Mali