factors affecting the accuracy of eyewitness testimony - misleading information Flashcards
eyewitness testimony (EWT)
the ability of people to remember the details of events, such as accidents and crimes, which they themselves have observed.
EWT can be affected by factors such as misleading information and anxiety.
misleading information
incorrect information given to an eyewitness usually after the event (hence called post-event information). it can take many forms, such as leading questions and post-event discussion between co-witnesses and/or other people.
leading questions
a question which, because of the way it is phrased, suggests a certain answer.
e.g. ‘was the knife in his left hand?’ leads a person to think that’s where the knife was.
post-event discussion
occurs when there is more than one witness to an event. witnesses may discuss what they have seen with co-witness or with other people. this may influence the accuracy of each witness’s recall of the event.
research on leading questions
when you are asked a question, the wording of the question may lead (or mislead) you to give a certain answer. this is a particular issue for EWT because police questions may direct a witness to give a particular answer. in the experiment, words such as smashed or bumped were used to suggest the car.
procedure on leading questions
loftus and palmer (1974) arranged 45 participants (students) to watch film clips of car accidents and then asked them questions about the accident
in the critical question (a leading question or also called misleading information) participants were asked to describe how fast the cars were travelling: ‘about how fast were the cars going when they hit each other?’
there were five groups of participants and each group was given a different verb in the critical question. one group had the verb hit, others had contacted, bumped, collided, smashed.
findings on leading questions
the mean estimated speed was calculated for each participant group.
results: verb: mean contacted 31.8 hit 34.0 bumped 38.1 collided 39.3 smashed 40.5
why do leading questions affect EWT?
the response-bias explanation suggests that the wording of the question has no real effect on the participants memories, but just influences how they decide the answer. when a participants gets a leading question using the word smashed, this encourages them to choose a higher speed estimate.
loftus and palmer (1974) conducted a second experiment that supported the substitution explanation, which proposes that the wording of a leading question changes the participants memory of the film clip.
this was shown because participants who originally heard smashed were later more likely to report seeing broken glass (there was none) that those who heard hit. the critical verb altered their memory of the incident.
research on post-event discussion
eyewitness to a crime may sometimes discuss their experiences and memories with each other.
procedure on post-event discussion
fiona gabbert et al. (2003) studied participants in paris. each participant watched a video of the same crime, but filmed from different points of view. this meant that each participant could see elements in the event that the other could not.
e.g. only one of the participants could see the title of a book being carried by a young woman.
both participants then discussed what they had seen before individually completing a test of recall.
findings on post-event discussion
the researchers found that 71% of the participants mistakenly recalled aspects of the event that they did not see in the video but had picked up in the discussion.
the corresponding figure in a control group, where there was no discussion, was 0%. this was evidence of memory conformity.
why does post-event discussion affect EWT?
one explanation is memory contamination. when co-witnesses to a crime discuss it with each other, the EWTs may become altered or distorted. this is because they combine (mis)information from other witnesses with their own memories.
another explanation is memory conformity. gabbert et al. concluded that witnesses often go along with each other, either to win social approval or because they believe the other witnesses are right and they are wrong. unlike memory contamination, the actual memory is unchanged.
