Misinformation effect
Misleading information encountered after an event rewrites the memory of it.
What it means
The misinformation effect is the distortion of memory for an event caused by exposure to misleading information after the event has occurred, such that the post-event information becomes incorporated into, or overwrites, the original recollection. It is powerful evidence that human memory is reconstructive rather than a faithful recording: rather than replaying a fixed trace, the mind rebuilds memories at retrieval and can blend in details supplied later, sometimes from a question's very wording. Loftus's studies showed that even subtle linguistic framing — asking how fast cars were going when they 'smashed' versus 'hit' — inflated estimated speeds and could implant phantom details like nonexistent broken glass. Debate continues over the underlying mechanism: whether misinformation overwrites and erases the original trace, merely blocks access to it, or fills gaps where the original was never well encoded, with source-monitoring failures (confusing where a detail came from) playing a key role. It matters acutely for the reliability of eyewitness testimony and the dangers of leading or suggestive questioning, and more broadly for how rumor, media, and post-event discussion can quietly reshape what people sincerely believe they remember.
Examples
Witnesses asked how fast the cars were going when they 'smashed' into each other recall higher speeds — and a week later are more likely to 'remember' broken glass that was never there.
A colleague mentions the client 'seemed annoyed from the start,' and you recall the meeting as tense throughout — though your own notes show the mood only turned near the end.
A shopper reads a recall notice describing a blue label and later remembers the blue label on the box in her cupboard; the packaging she bought was plain white.
First described in Elizabeth Loftus (1974).
Where this comes up
- Yesterday, Re-written: The Science Behind MemoryEvery time you remember the past, you risk changing it.