EvidenceProf Blog

Editor: Colin Miller
Univ. of South Carolina School of Law

Thursday, July 14, 2016

Interesting Study on the Illusion of Truth Effect and Eyewitness Suggestibility

For those of you interested by the discussion of the illusion of truth effect in Episode 1 of Season 2 of Undisclosed, here's an interesting study about the illusion of truth effect and eyewitness suggestibility: (Download Illusion of Truth Study). Here is the abstract:

The purpose of the present study was to extend research on repetition and illusory truth to the domain of eyewitness suggestibility. Specifically, we assessed whether repeated exposure to suggestion, relative to a single exposure, facilitates the creation of false memory for suggested events. After viewing a video of a burglary, subjects were asked questions containing misleading suggestions, some of which were repeated. Their memory for the source of the suggestions was tested. The results show that following repeated (relative to a single) exposure to suggestion, subjects were more likely to (a) claim with high confidence that they remembered the suggested events from the video (Experiment 1) and (b) claim that they consciously recollected witnessing the suggested events (Experiment 2). The effects of repeated exposure were highly reliable and were observed over retention intervals as long as 1 week.



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I had to appear as a witness to recount what a client told me (i wrote her will, privilege was waived) in a courtroom. Made me nervous! As a trial attorney, I relied on many a witness to win a case. As a citizen observing negligent driving, several times, I really found it helpful to write what I saw immediately. It isn't easy.

Posted by: Linnette Garber | Jul 15, 2016 7:03:27 AM

Yes, contemporaneous notes are great.

Posted by: Colin Miller | Jul 15, 2016 1:26:36 PM

I saw this illusion of truth effect play out in front of me when I was in highschool, with devestating consequences too. I was 15 at the time and a rumour started spreading around the school that one of my best friends was pregnant to a guy in our class. This was in the early 90s, and at 15 neither myself or my girlfriends were sexually active, let alone pregnant. Me and all my mates defended our friend (of course) and denied the stories wherever possible but it was a futile effort. To cut a long story short, we eventually discovered that my friend had started the rumour about herself in the hopes that it would bring her and the boy she liked (the alleged “daddy” of this non-existant baby) closer together. Shared persecution or something like that. This is where the illusion of truth effect comes in. My friend was never pregnant, and once the truth about the rumour's origin came out, the Principal, the guidance counseller and her parents had a meeting where it was decided that she should either leave school or transfer to a different school. She'd totally screwed up the boy's life, he was being bullied and actually got beaten up at one point and she was being bullied and ostracised as well. She decided to drop out rather than transfer, and the Principal actually took the extra step of informing an entire school assembly that “recent rumours about certain students” were untrue. But to this day (and I know because I tested it recently) if you ask people who went to that school with us “do you remember [my friend's name]?” the standard response you will get is “Yeah, she's the one who had to drop out because she was preggers.”

Posted by: Sakura | Jul 20, 2016 2:27:37 PM

Illusion of truth can work both ways. Seems to me that you guys on the podcast hold a consensus view that Amanda Knox was wrongfully convicted. Would you not consider that you could be under an illusion of truth perpetrated by the American media? We in Europe generally do not hold the same view of her innocence (it could be our own illusion of truth of course, or it could be a better understanding of Italy’s (ancient) judicial process and the evidence put before the courts). Either way, I was disappointed to hear an assumption of a ‘truth’ without evidence being presented, especially in that particular episode. And also I didn’t like to hear an assumption of ‘European attitude’ towards her lifestyle. If it is in any way possible for millions of people to think the same way, I would say in general Europeans have a more relaxed attitude to whichever way someone wants to live than what we are told of America and most people would not assume lifestyle choices would make someone murder their flatmate in any case. The reason we do not necessarily believe in her innocence is about the evidence, not assumptions. Anyway… generally love the podcast and am full of admiration for you guys and what you have achieved for Adnan.

Posted by: Charlotte | Jul 22, 2016 5:01:56 AM

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