How you ask your question can manipulate the response- weaknesses in memory.

Any investigator who is tasked with solving a case must first understand their job is to seek the truth.  This may sound obvious, but it deserves mentioning.  When interviewing a witness, victim or suspect it is important to understand that how you ask a question may have a significant impact on the answer you receive.  Phrasing a question a certain way can strongly influence the response.  By mere suggestion it is possible to alter the memory of a subject.

Memory does not work like a video camera.  It does not record the information in its entirety.  There are different kinds of memory.  Episodic memory is that in which we remember an event.  This is the type of memory in play during most investigations.  When a subject observes an event, the event is encoded into memory.  Not every detail gets encoded.  Those details can be filled in by the creation of the subject’s own narrative.  In other words, he may make up the details or guess.  This is where the suggestion of an interviewer may alter the subject’s recollection of events.

Psychologists Elizabeth Loftus and John Palmer conducted an experiment in 1974 to test the level of influence the way a question is asked can have on the response.  They asked people to estimate the speed of two vehicles involved in a crash.  People are generally not very good at estimating speeds unless they have had specialized training, which is usually reserved for police officers.

The study concluded that the use of harsher descriptions of the accident lead to the witness stating the speeds were higher.  When asked how fast the red car was going when it “contacted” the blue car, the  witnessed stated the speed to be significantly slower than when the term “smashed” was used in the place of “contacted”.  Other terms used were “hit”, “bumped” and “collided”.  Each of these terms brought an increased estimation of the speed.

The chart below outlines the affect the descriptive term had on the respondent’s estimation of the speed at the time of the accident.


As you can see, the more intense the description of the accident was, the higher the speed was estimated to be.  When “contacted” was used, the average estimated speed was 31 mph.  When “smashed” was used, the average response was 41 mph.

Furthermore, those witnesses that were asked the question with the “smashed” term used were far more likely to recall the damage to the vehicles as more severe. In the video the subjects had watched there was no broken glass. In response to the follow up question “Did you see any broken glass?” 16 out of 34 subjects in the “smashed” group stated that they did see broken glass.  The control group (they had not been asked about the speed of the cars at the time of the accident) had 44 state no to the broken glass and 6 said yes there was broken glass (see how reliable eyewitness memory is?).  Those subjects in the “hit” group had 7 yes responses and 43 no responses. (Loftus and Palmer, 1974)


As this study indicates, it is important to keep your line of questioning as neutral as possible (if the truth is what you are after).  Avoid the leading questions. The truth is what the professional investigator is after, and in order to get the truth it is imperative that witness testimony is not tainted with poor or unfair questioning strategies.


4 thoughts on “How you ask your question can manipulate the response- weaknesses in memory.

  1. Andrea

    How the questions are asked can also affect rapport. One reason I dislike polls is because the questions are often asked in such a way that I feel like they don’t really want my opinion, they want to nudge me into giving the opinion they want to hear. If investigators questioned that way, they’d probably get inaccurate answers as well as cause the interviewee to distrust them. I find it interesting that the chosen verb predictably changes the response, though, especially considering that modern marketing overexposes people to exaggerated language.

  2. Bob Pointer

    Another spot on article Ryan.

    As an NLP Practioner I use embedded commands speaking to the unconscious mind I also use reframing techniques to encourage change on an individual. However I only use these in a positive way because I know the power of them. An example being I implanted a message in a clients mind they did not need to be on anti depressants a few days later they called me to say they had decided to come off the drugs. As far as she was concerned it was her decision.

    Taking that into the field of investigations I would never consciously using it as a tactic but know that it can be done mostly by ineffectual or I’ll trained individuals. In the defence of interviewers it is hard to manage all the various parts that make up effective communication and monitor every single word and question for its interpretation by the interviewee. This is why I am an advocate of staged I terviews with a series of short topic specific interviews which together make the whole.

    1. Ryan Mann, CFE Post author

      Bob, thank you for the kind words. Coming from you, they are truly humbling.

      I couldn’t agree with you more. The key to being a professional interviewer is to take all precautions against unfairly influencing the outcome of the interview.
      If we are not mindful of our approach, we may accidentally influence the respondent. Of course, we should never intentionally manipulate the respondent.
      Preparation is key!

      Thanks for commenting!


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