Eyewitness evidence

[SKIRRID5]

There is an item on the BBC news site today which emphasises how unreliable eywitness evidence is. It relates to that sad event in Crete where two kids fell from a hotel balcony, one being fatally injured. Their father was found not guilty of murder. Today's item concerns two witnesses of the event, a man and wife. The wife says straightforwardly that the father pushed the kids, she being surprised he didn't try to save them. The husband says the father DID try to save them as they fell.
Very many claims of paranormal events or sightings of strange things rely on eyewitness accounts. Here we have a perfect indication of the worth of these accounts as evidence.

[DrS]

There was an advert running on television some years ago, I think it was for the Guardian but might have been another broadsheet, where the same scene was filmed from two very different angles. From memory, in one, a young man was running towards a middle-aged woman to steal her purse; in the other, he was running towards her to push her out of the way of falling masonry (or similar).

There are issues of perspective, as well as immediate (and possibly often inaccurate) assessment of visual evidence.

[bobdezon]

I remember that advert well.

[ZERO]

Don't forget, as well as being mistaken, eyewitnesses can straight out lie.
People and their memories are so unreliable there is a case to be made that witness testimony should not be admissible as evidence in a court. (IMO)

[Admin]

There was an advert running on television some years ago, I think it was for the Guardian but might have been another broadsheet, where the same scene was filmed from two very different angles. From memory, in one, a young man was running towards a middle-aged woman to steal her purse; in the other, he was running towards her to push her out of the way of falling masonry (or similar).

There are issues of perspective, as well as immediate (and possibly often inaccurate) assessment of visual evidence.

Yes, that's quite a famous advert.

It's an example illustrating that what we see (or strictly speaking, perceive) is as much a result of what we expect to see as it is a result of what really happened.

Eye-witness testimony is still allowed in court but only as supporting evidence rather than being primary evidence in itself (IIRC). The reliability of eye-witness testimony is now known to be far poorer then once believed.

[Tomolac]

was studied many years ago, back in the 1930s, the BBC are a bit behind :cheesy:
http://en.wikipedia.org/wiki/Schema_(psychology (http://en.wikipedia.org/wiki/Schema_%28psychology))
there are many many case studies on the subject so I'll just mention the one done by Allport and Postman, in which they showed participants a picture of a black man having a heated discussion with a white man holding a knife. not very surprisingly they found that when asked to recall it later, the white participants would recall the black man holding the knife. on an up note apparently more recent test have begun to show that people recall it more accurately now, probably due to racial acceptance, but it still shows how our memory can be easily affected by our preconceptions.

[Janot]

When I was a student working as a bus conductor in Eastbourne during the summer, this had just happened. A bus arrived at the terminus, and changed direction by a 3-point turn involving reversing. Whilst reversing, the bus ran over an elderly lady who had got off the bus and walked behind it.

There were 12 people waiting for the bus at the bus stop, so they all had a ring-side seat. At the inquest, 6 said the conductor was behind the bus with a whistle (as per rules) and the other 6 said he was sitting inside the bus.

This left a lasting impression on me ....Mind you, it was Eastbourne. ::)

[Fiona]

was studied many years ago, back in the 1930s, the BBC are a bit behind :cheesy:
http://en.wikipedia.org/wiki/Schema_(psychology (http://en.wikipedia.org/wiki/Schema_%28psychology))
there are many many case studies on the subject so I'll just mention the one done by Allport and Postman, in which they showed participants a picture of a black man having a heated discussion with a white man holding a knife. not very surprisingly they found that when asked to recall it later, the white participants would recall the black man holding the knife. on an up note apparently more recent test have begun to show that people recall it more accurately now, probably due to racial acceptance, but it still shows how our memory can be easily affected by our preconceptions.

Off topic, but I am very encouraged by that :smiley:

[tablemonkey]

I remember that advert well.

Yes, I remember it well too. I have used that scenario to explain to my kids why they shouldn''t take everything at face value.

[Croydon Bob]

I remember that advert well.

So do I. And the rest of you are remembering it all wrong.




;)

[bobdezon]

Anyone remember more details of that advert? Im trying to find a copy but I only remember certain details about it and nothing is proving useful in a search. :'(

[Mongrel]

Anyone remember more details of that advert? Im trying to find a copy but I only remember certain details about it and nothing is proving useful in a search. :'(

http://uk.youtube.com/watch?v=E3h-T3KQNxU

[bobdezon]

Egads O0 We should make babies >:D Cheers matey.

[Mongrel]

Egads O0 We should make babies >:D

A hearty handshake and maybe a beer at some point is quite sufficient, thank you ;)

[Graham Lappin]

I remember years ago there was an exhibition at the science museum in London, where they played a short film and then asked questions afterwards. The film however had had some of the sounds and images mixed up. Not all of them and not voices just car doors shutting, some gun shots etc (you played the part of a witness in a robbery). I recall how surprised I was when at the end all was revealed. The brain just seemed to fill in the gaps or unscramble the sounds and images into something that seemed to make sense. Very interesting but a little disturbing.

You must be aware of http://www.youtube.com/watch?v=voAntzB7EwE ?

[Tony Williams]

There's a fascinating experiment which involves a member of the public, picked at random, who is walking along a path. An experimenter stops the subject and asks him/her for some directions. Part-way through the conversation, two men carrying a large board pass between the experimenter and the subject, so that the subject's view of the experimenter is completely blocked. Hidden from the subject, there is another man walking along behind the board, and he switches places with the experimenter and continues the conversation with the subject.

This experiment has been run several times and usually results in about half of the subjects not noticing the switch, despite the fact that the experimenter's appearance and dress are only generally similar to his replacement's.

Another experiment was laid on by the British police some years ago, at a magistrates' conference. As the magistrates left the building at the end of a session, the police staged a near-accident involving some cars, right in front of them. The magistrates were then asked to describe what they had seen, and the results were instructive: their accounts varied greatly in the sequence of the events, the colour of the vehicles and even the number of vehicle involved.

There are many examples from case law when witnesses have been absolutely certain that they have identified the person they clearly saw committing a crime, only to be proved wrong. Very worrying...

[Dr B]

Hi Tony

The experiment you mention first is one carried out by Dan Simons and is on an attentional effect known as change-blindness.

Other researchers that you might want to read about are Ron Rensink and his group.

It's basically nothing new. In the 1960s it was short-term memory failure, in the 1970s it was working memory failure. Now its been given a new name and a lot of people get excited about it.

I find it fascinating - but it is a re-branding of an effect with a long history in cognitive psychology.

Rensink has an interesting detailed model (indeed he is one of the few that actually gets to grips with the psychology and is not just seduced by the striking effect) that you might want to read about.

A related and even more striking phenomena is that of sustained inattentional-blindness where observers can be unaware of salient information that is clearly present in the visual field. Detailed models of this effect are even thinner on the ground - but i know of one British scientist who has proposed an important one (with colleagues ::))

Other reasons for poor eye-witness testimony include false-memory and you should take a look at the work of Loftus, and Johnson for some nice papers on that.

[Tony Williams]

Thanks for that...I find the continuing discoveries about the often bizarre ways in which the human mind works (or doesn't work) really fascinating.

I think that the worst case of faulty eyewitness evidence I ever heard of came from the American woman (intelligent and well-educated) who was raped in broad daylight. She had several minutes in which to study his face at a distance of a few inches. She picked him out of a line-up and was certain she had the right man. She maintained this certainty through his failed appeal. Only when incontrovertible evidence emerged that it could not possibly be him (and a known rapist eventually admitted the deed) did she realise that she had made a terrible mistake.

One factor was probably that she was white and the rapist was black - humans seem to be much more sensitive to facial differences in people of their own race ("they all look the same!"). The other was that, having made the initial error at the line-up, the person she was remembering the rest of the time wasn't the rapist, but the man she saw in the line-up.

A salutary example...

[polomint38]

One factor was probably that she was white and the rapist was black - humans seem to be much more sensitive to facial differences in people of their own race ("they all look the same!").

This is true but I have found that people who are brought up in areas with a very mixed population racially, are better at distinguishing those of races other than their own, than those brought up in primarily single race areas.

This is just by my observation, I no of no studies to back this up sorry, but what are you thoughts. :cheesy:

[Tony Williams]

This is true but I have found that people who are brought up in areas with a very mixed population racially, are better at distinguishing those of races other than their own, than those brought up in primarily single race areas.

This is just by my observation, I no of no studies to back this up sorry, but what are you thoughts. :cheesy:

That seems entirely reasonable to me. Recognition depends to a great extent on familiarity.

[farmersboy]

'tis true - I was brought up in a white community (1 black kid in 11 years of school), and 'they' all look the same to me, pretty much.

[migomigs]

Eyewitnesses in a courtroom may play the role of the storyteller. He is important not because he is telling the truth but because he may lead to the truth by telling the story that doesn't have flaws, when viewed at his perspective. It may look incorrect at other perspective but it should be consistent at least at one perspective. Who else could tell a flawless stroy than the one who has been present at that time. It would be easier to convey a point when presenting evidences in a logical manner, in this case, siting the evidences at specific points of time and space in a sequence of events told by eyewitnesses. ::)

[Mulder]

Eyewitnesses in a courtroom may play the role of the storyteller. He is important not because he is telling the truth but because he may lead to the truth by telling the story that doesn't have flaws, when viewed at his perspective.

The word 'truth' is a tricky one with regard to witnesses. Many witnesses may tell the 'truth' in that they relate what they remember. However, it is frequently not the same as what actually happened. This is easily demonstrated by staging an 'incident' in front of witnesses and then asking them what happened. The tendency to remove 'flaws' in a memory is the cause of this problem. Witnesses will often unconsciously change a memory (confabulate) so that it 'fits' with the view they take of the incident after it is over. I think relying on witness memory alone in a court is dangerous.

[Dr B]

Hi Tony

In some senses though, recognition and Familiarity are not the same thing. You can recognise a teapot as a teapot - but feal no familiarity torwards towards it (even if it is your teapot). Recognising it and feeling it as familiar do appear to be largely separable processes.

This is also indexed by recent research on face processing as well as in autobiographical memory research.

Consider Capgras delusion - where the patient thinks that a relative (often a spouse) has been replaced by an imposter. The patient 'recognises' the individual as their wife / husband - but, due to brain lesions, feels no 'familiarity' towards them. This then is thought to underlie why such patients generate delusory explanations such as 'an imposter' - they are trying to explain why they feel no familiarity for what should be the familiar.

Fregoli delusion is another example but from a slightly different angle. O0 Note - these are delusions of familiarity and not problems with recognition.

[StoneQuarry]

I prove this to myself often.
Sometimes I am lying in bed at night and think I see something moving across the room.
I turn my head only to realize that it was a shadow. This is usually pareidolia due to the fact that I am tired, the fan is spinning, cars are moving outside and other factors. I realized I can never trust my eyes 100% and should pay very close attention if/when I ever see a crime happening. ^-^