The misinformation effect occurs when misleading information received after an event distorts a person's memory of that event, showing that memory is reconstructive rather than a perfect recording. In AP Psychology it appears under retrieval and memory distortion, tied to Elizabeth Loftus's eyewitness research.
The misinformation effect is what happens when information you encounter after an event gets blended into your memory of the event. You don't notice it happening. Your brain doesn't store memories like video files; it rebuilds them every time you retrieve them, and during that rebuild, post-event information (PEI) can slip in and overwrite the original details. The result feels like a genuine memory, but parts of it are false.
The classic demonstration comes from Elizabeth Loftus's car-crash studies. Participants watched the same collision, but those asked how fast the cars were going when they "smashed" into each other later remembered broken glass that was never there, while those asked about cars that "hit" each other did not. One leading verb rewrote the memory. That's the core idea you need for the exam: the misinformation effect is evidence that memory is constructive (built at encoding) and reconstructive (rebuilt, and possibly distorted, at retrieval). It's covered in the Retrieving and Forgetting and Memory Distortion study guides.
This term lives in the memory topics of the course (Introduction to Memory, Retrieving, and Forgetting and Memory Distortion). It's the single best piece of evidence for the big claim those topics make, which is that memory is an active reconstruction, not a playback. It also connects forward to treatment. The CED (under 5.5.E) states flatly that research does not support using hypnosis to retrieve accurate memories, and the misinformation effect is the reason why: a suggestible state plus leading questions is a recipe for false memories. Beyond the test, this concept has real stakes. Eyewitness testimony has sent innocent people to prison, and Loftus's research is why courts now treat eyewitness confidence with skepticism. The College Board clearly cares, since the 2025 AAQ built an entire research-analysis question around a misinformation study.
Keep studying AP Psychology Unit 5
Post-Event Information (PEI) (Unit 5)
PEI is the cause; the misinformation effect is the result. Anything you encounter after an event (a leading question, a news report, another witness's account) counts as PEI, and when it changes what you remember, that change is the misinformation effect. On an MCQ, if the stem describes someone's recall getting less accurate after exposure to new information, PEI is the mechanism to name.
Implanted Memories (Unit 5)
The misinformation effect distorts details of a real event. Implanted memories go further and create an entire memory of something that never happened, like Loftus's famous "lost in the mall" study. Think of them as two points on the same spectrum of false memory, with implantation as the extreme end.
Confabulation (Unit 5)
Both produce false memories that feel real, but the source differs. Confabulation is your brain filling memory gaps on its own, with no outside input needed. The misinformation effect requires an external source of misleading information. If the question mentions where the false detail came from, that's your tiebreaker.
Hypnosis and Memory Retrieval (Unit 5)
The CED states that hypnosis works for pain and anxiety but not for recovering accurate memories or age regression. The misinformation effect explains why. A hypnotized person is highly suggestible, so a therapist's questions can become post-event information that gets woven into "recovered" memories. This is a great cross-topic link for an FRQ on memory or treatment ethics.
On multiple choice, the misinformation effect shows up two ways. First, conceptually: "What does the misinformation effect illustrate about memory?" The answer is always some version of memory being reconstructive and vulnerable to distortion. Second, in scenarios: a witness recalls an event differently after hearing misleading details, and you have to name the phenomenon or identify post-event information as the cause. Watch for distractors like retroactive interference and confabulation, because the test loves putting them in the same answer set.
It also appears in research-based free response. The 2025 AAQ Q1 presented a study on how varying amounts of misinformation about an event affected 127 students' memory of it. For that format, you need to do more than define the term. Be ready to identify the independent variable (amount of misinformation) and dependent variable (memory accuracy), evaluate the method and generalizability, and use the data to support a claim. Knowing Loftus's findings gives you the framework to interpret results like that quickly.
These look similar because both involve new information messing with old memories, but they do different things. Retroactive interference makes you forget old material because new learning blocks access to it, like your new locker combination crowding out last year's. The misinformation effect doesn't block the memory; it rewrites it, so you confidently recall details that are wrong. Quick test for the exam: if the person can't remember, think interference. If the person remembers incorrectly, think misinformation effect.
The misinformation effect occurs when misleading post-event information distorts a person's memory of the original event.
It is the strongest evidence that memory is reconstructive, meaning the brain rebuilds memories at retrieval rather than replaying a recording.
Elizabeth Loftus's car-crash studies showed that changing one word in a question ("smashed" vs. "hit") changed what participants remembered seeing.
The misinformation effect rewrites a memory, while retroactive interference blocks access to one; remembering wrong is misinformation, forgetting is interference.
It explains why the CED says hypnosis should not be used to retrieve memories, since suggestible states make false memories easy to create.
The 2025 AAQ featured a study on misinformation and memory, so be ready to identify variables and evaluate methods in a study using this concept.
It's the distortion of a memory caused by misleading information received after the event, such as a leading question or another witness's account. It demonstrates that memory is reconstructive, and it falls under the Retrieving and Forgetting and Memory Distortion topics.
No. Retroactive interference means new learning blocks your ability to recall older information, so you forget. The misinformation effect means post-event information alters the memory itself, so you remember confidently but incorrectly.
Confabulation is the brain filling memory gaps internally, with no outside source needed. The misinformation effect requires an external source of misleading information, like a suggestive question, that gets absorbed into the memory.
No. It proved eyewitness memory is malleable, not worthless. In her studies, swapping "smashed" for "hit" led people to falsely remember broken glass, which shows confidence doesn't equal accuracy and testimony can be contaminated by how questions are asked.
Yes. It appears in multiple-choice scenario questions, and the 2025 AAQ Q1 was built around a study testing how varying amounts of misinformation affected 127 students' memory of an event.