The Misinformation Effect: The Malleability of Human Memory and Investigative Interviewing

Elizabeth Loftus, a preeminent psychologist and memory researcher, fundamentally reshaped how professionals understand human memory. Her work revealed that memory is not a fixed recording of events, but a reconstructive process vulnerable to distortion. One of her most influential contributions is the misinformation effect, a phenomenon with direct and lasting implications for Investigative Interviewing.

The misinformation effect occurs when post-event information alters an individual’s memory of an event, often without their awareness (Loftus, 2005). For investigators, this research underscores a critical reality: how questions are asked, information is disclosed, and opinions are conveyed can permanently shape witness and suspect statements.

Sketch of brain

The Foundational Misinformation Effect Study

The misinformation effect was first formally documented in a landmark 1974 study by Elizabeth Loftus and John Palmer. Participants viewed film clips of traffic accidents and were later asked questions using different verbs to describe the collision, such as “hit,” “collided,” or “smashed” (Loftus & Palmer, 1974).

The results were striking. Participants exposed to more forceful language not only estimated higher vehicle speeds but were also more likely to report seeing broken glass that never existed. This study demonstrated that language alone can alter memory, a finding with profound consequences for investigative interviewing practices.

Later Research and Expansions

Subsequent research confirmed that the misinformation effect is robust and reliable across contexts. In a 1978 study, Loftus, Miller, and Burns showed participants a series of images depicting a car stopping at a stop sign before striking a pedestrian. Later, some participants were exposed to misleading information suggesting the sign was a yield sign. Those participants were significantly more likely to remember the yield sign instead of the stop sign (Loftus et al., 1978).

Perhaps most concerning for investigators was Loftus and Pickrell’s 1995 study demonstrating that entirely false memories could be implanted. Participants were led to believe they had been lost in a shopping mall as children—an event that never occurred. Many later recalled vivid details of the fabricated memory, illustrating how misinformation can go beyond distortion and create new, false recollections.

Why the Misinformation Effect Matters for Investigative Interviewing

These findings fundamentally challenge the assumption that memory operates like a video recording. In Investigative Interviewing, statements are often treated as factual anchors for case development. Loftus’s research makes clear that statements can be unknowingly shaped by investigator behavior, question framing, and post-event exposure.

In legal and investigative settings, this means contamination risks are not theoretical, they are predictable and preventable.

Best Practices in Investigative Interviewing to Prevent Misinformation

Separate Interviewees

Separating witnesses is a cornerstone of sound investigative interviewing. When witnesses discuss events with one another, memory contamination becomes likely, as individuals unconsciously integrate details from others into their own accounts. Separation preserves independent recollections, increasing accuracy and protecting evidentiary value.

Avoid Leading Questions

Leading questions are a primary driver of the misinformation effect. Asking “Did you see the broken window?” instead of “What did you observe?” introduces details that may become embedded in memory. The Cognitive Interview (Fisher & Geiselman, 1992) explicitly warns against such practices, emphasizing open-ended, neutral questioning to protect memory integrity.

Strategic Use of Evidence (SUE)

The Strategic Use of Evidence technique mitigates misinformation risk by delaying evidence disclosure until after a free narrative and funnel questioning is completed. SUE allows investigators to capture an uncontaminated, corroborated account before introducing any evidence, preserving the diagnostic value of statement-evidence inconsistencies without shaping memory or distorting statements.

Maintain Interviewer Neutrality

Investigator opinions—whether spoken directly or implied—act as powerful post-event information. When interviewers reveal assumptions, beliefs, or theories, interviewees may unconsciously alter their accounts to align with perceived expectations. Effective investigative interviewing requires disciplined neutrality to avoid shaping memory.

The Standard: Uncontaminated, Corroborated Statements

High-quality investigative interviewing produces statements that are both uncontaminated and corroborated. Science-Based Interviewing relies on peer-reviewed research to reduce memory distortion, manage bias, and preserve evidentiary integrity in all investigative interviews. These principles protect investigations, improve accuracy, and strengthen cases long before they reach court.

Conclusion

Elizabeth Loftus’s research on the misinformation effect permanently changed how investigators, courts, and researchers understand memory. Her work revealed that memory is vulnerable, malleable, and highly sensitive to suggestion, especially during interviews.

For modern Investigative Interviewing, this research is not optional knowledge. It is foundational. Ethical, effective investigations depend on interviewing methods (like Science-Based Interviewing) that respect memory limitations, avoid contamination, and prioritize reliable information over convenience. When investigators understand how misinformation operates, they are better equipped to protect the truth, and the integrity of justice itself.

Misinformation Effect References

Fisher, R. P., & Geiselman, R. E. (1992). Memory-enhancing techniques for investigative interviewing: The cognitive interview. Charles C. Thomas Publisher.

Loftus, E. F., Miller, D. G., & Burns, H. J. (1978). Semantic integration of verbal information into a visual memory. Journal of Experimental Psychology. Human Learning and Memory, 4(1), 19–31. https://doi.org/10.1037//0278-7393.4.1.19

Loftus, Elizabeth F. (2005). Planting misinformation in the human mind: a 30-year investigation of the malleability of memory. Learning & Memory (Cold Spring Harbor, N.Y.), 12(4), 361–366. https://doi.org/10.1101/lm.94705

Loftus, Elizabeth F., & Palmer, J. C. (1974). Reconstruction of automobile destruction: An example of the interaction between language and memory. Journal of Verbal Learning and Verbal Behavior, 13(5), 585–589. https://doi.org/10.1016/s0022-5371(74)80011-3

Loftus, Elizabeth F., & Pickrell, J. E. (1995). The formation of false memories. Psychiatric Annals, 25(12), 720–725. https://doi.org/10.3928/0048-5713-19951201-07