Doctored Videos Easily Manipulate Eyewitnesses

By Brett Israel | September 16, 2009 3:21 pm

gavel_webA person can witness an event in real life, see a doctored video of the same event, and then convince themselves that what they saw on the video is what actually happened, according to a recent study that casts doubt on the reliability of eyewitness testimony.

Psychologists set up an experiment where they filmed two people sitting side by side–one experimental subject and one researcher pretending to be a participant–playing a gambling game where they bet phony money on whether or not they could answer multiple choice questions correctly. They were told that the person with the most money at the end would win a prize.

After the game, the researchers edited the video of the experiment so it appeared that the under-cover researcher was cheating by not giving money back after making a losing bet. The results showed that almost half of the people who watched a doctored video of an event believed the video rather than their actual experience, and some were even convinced to testify as an eyewitness to the fictitious happenings [LiveScience]. They were told to sign the eyewitness statement only if they were 100 percent sure that their partner cheated. Nearly 40 percent of those that watched the fake video decided their partner was cheating and signed the statement. The researchers published their results in a recent edition of the journal Applied Cognitive Psychology.

In an era of easily manipulated photo and video evidence, the researchers say their findings have major implications for law enforcement officials and policy-makers, adding yet more evidence that eyewitness testimony cannot always be accepted as fact []. The U.S. Supreme Court recently ruled that prison inmates do not have a right to DNA testing, so for some criminal cases, law enforcement agencies may never know just how reliable eyewitnesses are.

Related Content:
80beats: In a Sensory Hack, What You Touch Affects What You See
80beats: Think DNA Evidence Can’t Be Faked? Think Again.
80beats: Even “Impartial” Jurors Use Emotion and Self-Bias in Decisions

Image: flickr/ steakpinball

MORE ABOUT: decisions, memory, senses, vision
  • Tor Hershman

    Now here is a doc.TORed video with many 80 beats per min. & is awfully 😀 in an
    atheistic sort-a way.

  • Christina Viering

    It figures.

  • Brian

    I was once in a hotel; we had just arrived, never been there before, new city, new country, etc. Anyhow I was travelling with my Mom.

    I go up to the room because Mom has some minor but urgent task on her mind and doesn’t need me for it. After washing up I wait, and wait, and wait, but no Mom. Finally, like an hour later, I see her heading across the road, away from the hotel. I think “that’s strange”, but she’s an adult and maybe she wants to get on with the sightseeing. So I go too (there was a beach across the road), and eventually we meet there.

    When we get back, we go up to the room, but Mom’s luggage isn’t there, and yet she says she was in the room and deposited the luggage there. I explain that’s impossible and tell her why; I was in the room the whole time she would have needed to be there. She can’t find her keys either, and eventually I wear her down. She was never in the room. If she did she would have keys. Besides, why would a B&E luggage thief take her stuff and not touch mine?

    Next we go down to the desk and explain our problem. Our tour guide is there (thank goodness) and overhears (foreign languages and all that). The mystery is finally solved (mostly) when we explain that we each had separate keys to the room. This hotel had an old-fashioned keying system (I don’t merely mean keys versus cards. The keys and locks themselves were sturdy but clearly from another era completely).

    So our guide says, “That’s impossible. This hotel only has 1 set of keys per room for guests. The front desk has another set but they never give those out.” We insist, we both saw that each of us got a set of keys. We always do that and we did it here too. I think we even saw the front desk keys to our room right there, so they hadn’t given us their set. Finally our guide says “if you each got keys it was to 2 different rooms. It’s the only way.”

    And he was right! It took us another 20 minutes to figure out which other room Mom had gone to, but eventually we found it and her luggage. Oh, and her missing room keys? She had a purse with a LOT of pockets. The missing keys were buried in a particularly obscure pocket.

    The point of this tale is that for a while I had talked my mother into thinking that she hadn’t gone to her room (the incorrect one as it turned out, but still). I arrived at the wrong conclusion and talked her into believing me!

  • pavlovs peanut butter

    thank goodness politicians and newscasters are honorable people! Imagine what they could pull over on us…;ll

  • Fred

    “thank goodness politicians and newscasters are honorable people”

    My thinking exactly.


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