reliability of eye-witness accounts

Hey Schraf,A couple of us had a half-decent discussion on eye-witness accounts in the thread Evidence and testimonial: A fundamental split.Charles posted some studies that demonstrated how easily eye-witness accounts can become skewed.Definitely an important topic; I think many non-scientists operate under the misunderstanding that scientists act sort of like eye-witnesses to their own conclusions, rather than communicating with data (hence arguments from authority rather than evidence).

Actually, most of that sort of testimony is not admissable in the US court system, when it qualifies as "hearsay". I don't think it is a matter of "trust", as in ethical trust; but rather a matter of reliability. Many studies have shown that peoples testimony can easily be manipulated.That is, they do not know that they are giving false testimony, because they themselves are convinced by their own false memories.In one study, people were given a series of bizarre tasks to do, none of which involved kissing or a frog. The next day the same people were asked a series of questions, including "what was it like kissing the frog?" Fifteen-percent of people described details of "kissing the frog" even though they had never done so...In a separate study, people were asked to list the characters they had seen on a visit to Disneyland. If they had previously been exposed to a fake Disney advertisement with Bugs Bunny on it, they would describe an interaction with Bugs Bunny, even though Bugs is not owned by Disney and has never set foot inside of Disneyland.One-third of people "remembered" interaction with Bugs Bunny that did not occur.From this study: You state that the justice system as we know it could not have arose without eye-witness testimony. You are likely quite correct; though you must also realize that countless people have been sent to prison or their deaths based on incorrect testimony, whether delivered innocently or with malice.The view that eye-witness testimony is unreliable is not untrustworthy, cynical, or strange - it is simply the truth.

I think your asking the wrong questions - it's not so much about trusting your eyes, as it is about trusting your brain to accurately replay what your eyes saw some time ago...As an example, the study I mention above in the thread: I'm sure if people were staring at Mickey Mouse, and you asked them if they were staring at Bugs Bunny, everyone would answer correctly (given they knew who Bugs Bunny was...)However, ask the people after they have left the park, and a third of them will say they had seen Bugs Bunny under certain conditions.

Why is that?It doesn't matter whether or not you trust your memory of what your eyes have seen, the simple fact is that your memory is falliable. Studies have shown that memory is quite manipulatable; a false memory can be implanted in someone just by asking them a leading question.As an exercise to prove this point: accurately describe to me everything that your eyes saw while you were eating lunch three days ago. How about three weeks? years?You may be able to describe something outstanding that happened to you during lunch three days ago, but you've probably already forgotten, half-forgotten, or never stored many of the mundane details. Many eye-witness accounts are based upon what seemed like "mundane details" before a spotlight was shown on them as a key piece of evidence. The man that passed you on the street two months ago - what color sweatshirt was he wearing?I guess "I'm afraid you're missing the point". Just because you want your memory to be accurate doesn't make it so. The inaccuracy of your memory is not based on your personal preference. It's a fact of life.Do you honestly feel that every single memory you have is 100% accurate?

Funny, I thought you were arguing that we should trust our eyes, otherwise our lives would be adversely effected.People have false memories. It doesn't matter if "you do remember" something, because you could be remembering wrong, however real the memory seems to you. If you consider something a "landmark" in your life, it is quite likely that you may amplify the details of that memory since you've accepted it as life-altering.You do realize this is a thread on the accuracy of eye-witness testimony?

The same thing as?: "We should trust our eyes" is quite a different argument than "the stuff you do remember is what matters". Not 100% secure, no. Having that kind of attitude could send the wrong person to the electric chair. All memory is falliable, yours included. What you believe to have genuinely occurred may not have occurred at all. You are not immune to this phenomenon just because you want to be.I'll ask again, since you didn't answer the first time:

Then what did you mean by: It sure seems like you are stating that my decision to not trust my own viewpoint 100% was the wrong one, and that it would lead to me having a "bad existence". Now it's "alright" and you're fine living your life that way? This is the crux of the problem I have with your argument. You seem to be saying that if something is important, you will remember it correctly. That is simply not the case. Repeated reexamination of memories, which tends to happen with important ones, will likely amplify or distort those memories. The meaning of dreams and God to life decisions is not the subject of this thread. However, in a way, you've refuted your own argument:You've stated that dreams can be "real" enough that they can lead to life-changing events, and that is doesn't matter whether these dream "memories" are real or not. Kind of refutes your position that important life-shaping memories are correct, doesn't it? A dream memory is a false memory, but to you it is real enough to "turn your life around" - you are basing the course of your life upon the "memory" of something that didn't happen. Actually, I went back and checked. This is the first time you answered the question.Whether knowingly or not you've changed your argument and the details of that argument several times in the past several messages (while claiming you haven't)... it's getting a bit silly.

To add to contra's comments-Much of false memory doesn't simply involve "missing" details, it involves the brain interpolating information that isn't really there. In the baseball cap scenario, imagine you look away for a moment or leave the room briefly, and someone quickly and secretly changes your baseball cap with something generally similar in shape and color - say an upside down yellow cereal bowl. You may return your focus to your monitor and not notice the exchange for some time, until you actually choose to focus on the object - throughout that time your awareness will be that the hat is still there, because that is how your brain will fill in those details based on previous experience.Your brain interpreting/interpolating the baseball cap for the cereal bowl is a similar phenomenon to failing to notice the addition or substraction of a word in a sentence - one often reads the sentence with their brain adjusting for the error based on the expected pattern. (This is one reason it is always good to have someone else review your writing, since you may miss errors since your brain reads past mistakes based on your intended form of the sentence).Unfortunately similar interpolation can occur in eye-witness accounts of crimes as well, where the brain of someone who witnesses a crime committed in someone in a golden baseball cap "fills in" the face of an innocent person they passed on the street the day before that was also wearing a golden baseball cap.Compensation for such exchanges has been demonstrated in quite drastic scenarios, including the exchange of an entire person. Research has shown that you can actually exchange people during a conversation and not have the subject notice the change. You can see video of these experiments at the University of Illinois Visual Cognition Lab, as well as other experiments that are relevant.This message has been edited by pink sasquatch, 03-16-2005 01:32 PM