Case File 251 · Investigation Psychology

What Is the Misinformation Effect?

By Murder Book Editorial TeamPublished by Gungrounds, the studio making Murder BookPublished 3 October 2026Updated 3 October 2026

The misinformation effect is a change in how someone remembers an event after they are exposed to misleading information about it afterwards. If a witness sees something, and then reads, hears or is asked a question that contains a wrong detail, that detail can work its way into their later account. They may end up reporting the misleading version with genuine confidence, not realising that part of the memory came from the later information rather than the event itself. The effect is one of the most studied findings in memory research. It shows that memory is not a fixed recording that is simply played back, but a reconstruction that can be reshaped by what happens after the fact. It does not mean a witness is lying or unreliable by nature; it means memory is open to influence.

Key takeaways

The misinformation effect is the impairment of memory that arises after exposure to misleading post-event information.
It was first demonstrated in the 1970s by Elizabeth Loftus and colleagues, whose work showed that the wording of a question could shift what people later reported.
A witness can report a misleading detail with real confidence and no sense that it came from outside the original event.
The effect appears across many settings, and some groups, such as young children and older adults, can be more susceptible.
It is a reason to gather accounts early and cleanly, not a sign that a particular witness is dishonest.

Where does the term come from?

The misinformation effect grew out of a programme of research begun by the psychologist Elizabeth Loftus in the 1970s. In a 1974 study with John Palmer, "Reconstruction of an automobile destruction", participants watched films of car accidents and were then asked about the speed of the vehicles. The question was worded differently for different groups. When the verb was "smashed", people gave higher speed estimates than when it was "hit". A week later, those asked the "smashed" question were also more likely to report having seen broken glass, although there had been none. The wording of a single question had nudged what people remembered.

In a 2005 review, "Planting misinformation in the human mind", Loftus summarised roughly 30 years of research and defined the effect as the impairment in memory for the past that arises after exposure to misleading information. She described it as one of the most influential findings in psychology, precisely because it showed how easily people could be led to report things they had not actually seen.

What does the research actually show?

The basic finding has been reproduced many times and in many forms. A witness encounters an event, is later exposed to some misleading detail, and then is tested on what they remember. Compared with people who received no misleading information, those exposed to it are more likely to report the false detail as part of their original memory.

Loftus's 2005 review drew several broader conclusions from the decades of work:

Misinformation can come from many channels: leading questions, conversations with other witnesses, media coverage, or a careless remark during an interview.
The effect is not limited to trivial details. Later research by Loftus and others explored how people could come to believe in whole events that never happened.
Warnings sometimes help. Telling people in advance that they may encounter misleading information can reduce, but does not eliminate, the effect.
Susceptibility varies. The review notes that some groups are more open to misinformation than others.

The point is not that everyone's memory collapses at the first wrong word. It is that memory is reconstructive, and reconstruction can incorporate material that was never part of the original experience.

Does the effect mean the original memory is gone?

This is a long-running debate in the research, and the honest answer is that it is not fully settled. Some accounts suggest the misleading information overwrites or impairs access to the original memory. Others argue that both versions can coexist and that the person simply reports the more recent or more accessible one, or cannot tell which source a detail came from. This last idea connects closely to source-monitoring error, where a memory is real but its origin is misattributed.

For an investigator, the practical consequence is the same either way. Once an account has been exposed to outside information, it is difficult to be sure which parts came from the event and which came from afterwards. That is why the condition of a witness's memory before any contamination matters so much. See memory contamination for how outside information gets in.

Why does it matter for investigations?

Eyewitness accounts are often central to a case, and the misinformation effect is one reason they must be handled carefully. A confident, detailed, sincere account can still contain elements that were introduced after the event. Because the witness genuinely believes the memory, their confidence is not a reliable guard against the error. The relationship between confidence and accuracy is explored in does eyewitness confidence mean the memory is accurate?.

Good practice is built around protecting a memory before it can be reshaped:

Interview witnesses early, before rumour, news or discussion can seep in.
Keep witnesses apart so they do not blend accounts, a problem covered in why should witnesses be interviewed separately?.
Use open questions that invite free recall rather than questions that embed a particular answer.
Record what a witness said at each stage, so that changes can be traced.

None of this treats the witness as suspect. It treats memory as fragile.

Is a witness who shows the effect lying?

No. The central and most important point is that the misinformation effect happens without any intention to deceive. The witness is not inventing a story to mislead anyone. They are reporting, in good faith, a memory that has quietly absorbed later information. Treating the presence of a mistaken detail as proof of dishonesty misreads the evidence. A mistaken memory and a lie are different things, and the research on the misinformation effect is, more than anything, a caution against confusing them.

How does Murder Book use this idea?

Murder Book: The Art of Interrogation is an upcoming narrative interrogation game from Gungrounds, an independent studio in Zagreb, Croatia. Its cases are built around unreliable stories, narrative gaps and accounts that do not quite line up, which is exactly the territory the misinformation effect occupies. A detail that shifts between tellings is not automatically a lie; it may be a memory that has been reshaped by something the person heard or was asked afterwards.

The game is designed so that behaviour and inconsistency are prompts to look closer rather than verdicts. That framing fits the research: a changed or contaminated detail is a reason to ask where it came from, not proof of guilt. Cases are built for focused 5–10-minute sessions, and Murder Book is in development for PC (Steam) and mobile, with release currently planned for the end of Q2 2027. For a related idea about why accounts drift honestly, see why can two honest witnesses remember the same event differently?.