Study Shows How Video Can Corrupt Eyewitness Memory

Radley Balko | September 23, 2009

Wired reports on a fascinating new study showing how eyewitness memory can be influenced by video. Participants in the study were paired with a partner (who was actually part of the research team) to play a gambling-based computer game. The participants bet money on their own ability to answer multiple choice questions. The game relied on participants to honestly pay back money they'd earned when they got a question wrong.

After they had finished with the questions, the participants were told that their partner had cheated, even though the partner hadn't. One group of students were then shown a video that had been digitally altered to make the partner look as if he had actually cheated. Though they were told to only report their partner if they were 100 percent sure he had cheated, and that the partner would be punished based on their decision, about half the participants who viewed the video still reported their partner for cheating. The second group wassn't shown the video, but only told of its existence. Just 10 percent of them still reported their partner for cheating.

The article may overstate the study's lessons a bit, at least in their relevance to the criminal justice world. It seems unlikely that many criminal cases are tainted by video digitally manipulated to show obvious guilt—even if you're cynical enough to believe law enforcement officials would try it, I'd think it would be pretty easy for someone with expertise in video editing to detect. But the broader point—that eyewitness memory is highly susceptible to suggestion—is worth heeding, and has been confirmed in numerous other studies.

Comments

Bingo|9.23.09 @ 7:45PM|#

Just 10 percent?? If this is statistically accurate, it's terrifying that 10% of people will report someone on hearsay alone, even after observing the event.

Paul|9.23.09 @ 8:05PM|#

I'm not sure how to take this. I mean, we know eyewitness testimony is questionable without video...so now what?

BakedPenguin|9.23.09 @ 8:35PM|#

I'd think it would be pretty easy for someone with expertise in video editing to detect [alterations].

It depends on what was done and how it was done. Actual changes to the video / digital files will usually leave artifacts unless the people really know what they're doing.

However, if there was more than one camera, video clips from one could be placed prior to or after than clips from the other when they actually happened. This could radically alter the meaning of what is seen. Since we are used to movies & television giving us multiple angles and cutting them together, this kind of manipulation could easily go unnoticed - people would simply follow the narrative.

textual abuse|9.23.09 @ 8:48PM|#

Since we are used to movies & television giving us multiple angles and cutting them together, this kind of manipulation could easily go unnoticed - people would simply follow the narrative.

Yeah, like how those crappy ATM videos will cut to a close up for the money-shot. Sophisticated ATM aficionados know it has to be captured in one continuous shot or it's just a cheap fake.

The Angry Optimist|9.23.09 @ 8:48PM|#

I mean, the lesson here is "video causes self-doubt, and the tape don't lie". Not terribly important, in my mind. For my money, I thought it was common knowledge among legal types that eyewitness testimony is notoriously unreliable.

|9.23.09 @ 8:49PM|#

Most attorneys with trial experience laugh and laugh at the idea that direct testimony is somehow necessarily superior than so-called circumstantial evidence.

|9.23.09 @ 8:53PM|#

Superior to. Dangit.

Michael Ejercito|9.23.09 @ 9:38PM|#

Most attorneys with trial experience laugh and laugh at the idea that direct testimony is somehow necessarily superior than so-called circumstantial evidence.

The right combination of circumstantial evidence can certainly prove a case beyond a reasonable doubt.

But other combinations, not so much...

|9.23.09 @ 9:40PM|#

People believe what they see. If you fake a tape and the participant doesn't know that it's a fake, they'll believe the tape.

Why does anyone consider this controversial? If you put a fake license plate on your car and the traffic camera takes a picture of it, it will send the ticket to the wrong address! Duh!

|9.23.09 @ 9:59PM|#

I thought My Cousin Vinny proved how unreliable direct testimony is years ago.

|9.23.09 @ 10:13PM|#

I said superior, not perfect. And, of course, there are exceptions to the rule.

qwerty|9.23.09 @ 10:18PM|#

People believe what they see. If you fake a tape and the participant doesn't know that it's a fake, they'll believe the tape.

Why does anyone consider this controversial? If you put a fake license plate on your car and the traffic camera takes a picture of it, it will send the ticket to the wrong address! Duh!

I agree. The only thing surprising to me is that half of the participants didn't accuse the partner of cheating despite being shown video evidence.

|9.23.09 @ 11:21PM|#

While I usually agree with Radley, I'm not sure this post tells us much. Unless the eyewitness "sees" on the video something he is absolutely certain he was looking at himself--unless he has to go through the thought process of "that can't be right; I was looking at that VERY thing myself and COULDN'T have missed it," all this shows is that eyewitnesses to video tape find video tape of something they may well have missed convincing. WHY in this context would they even entertain the notion the tape was doctored?

dfd|9.23.09 @ 11:32PM|#

People believe what they see. If you fake a tape and the participant doesn't know that it's a fake, they'll believe the tape.

I think what's being missed here (and maybe wasn't made clear in the post, but is from the article) is that the people were not simply saying they believed the person had cheated because they saw it on tape, they were signing statements that they themselves had actually seen the other person cheating at the time.

When asked to describe what they had seen, some participants even invented memories. "One subject told us that the other person had acted suspiciously and taken money from the bank when there was clearly a cross on the screen," Wade wrote.

. . .

Upon debriefing, participants in the study expressed complete surprise that the video had been fake and that their memory was false.

So after seeing the video many falsely believed that they actually remembered the other person cheating -- not just that they believed the video itself.

BeesInTheBrain|9.23.09 @ 11:33PM|#

A big part of the equation that was missing from the article is if the students who confirmed the cheating were on the winning or losing end of the gambling game. If 50% of the students confirmed the cheating and 90% of those were on the losing end of the game then that says something completely different.

sully|9.24.09 @ 12:08AM|#

You tell people for years that eyewitness testimony can't be trusted. Then you show them sports referee decisions being appealed to and sometimes reversed by the video evidence. All the while they watch magicians prove that their eyes can be consistently fooled.

And then you're shocked, shocked!, that they believe the video more than they do their own former observations.

Going further, you the researcher design an experiment based on the lie that altered video is a true representation of events. And then you're shocked, shocked!, that some portion of 50% of people will misrepresent what they saw in person so as to make it agree with the video.

|9.24.09 @ 1:04AM|#

dfd: Thanks for your VERY helpful clarification. That IS very different. I withdraw my statement above.

J D|9.24.09 @ 2:54AM|#

All this proves the fallibility of the individual; thus, the free market is fallible.

|9.24.09 @ 4:16AM|#

You tell people for years that eyewitness testimony can't be trusted. Then you show them sports referee decisions being appealed to and sometimes reversed by the video evidence. All the while they watch magicians prove that their eyes can be consistently fooled.

I am not sure what you're getting at there sully. In an NFL game the video is taken from multiple angles, often angles that a ref on the field couldn't see. During a review, the refs can watch the video several times and slow it down. I don't think a magician's trick of distraction and quickness would stand up to this scrutiny.

Rich|9.24.09 @ 9:22AM|#

it's terrifying that 10% of people will report someone on hearsay alone, even after observing the event.

Trust me, it's not hearsay if it comes from a person in authority.

|9.24.09 @ 10:16AM|#

All this proves the fallibility of the individual; thus, the free market is fallible.

Silly Utopian, business failure is not a bug, it is a feature.