factors affecting the accuracy of eyewitness testimony - misleading information Flashcards
what is eyewitness testimony?
the ability of people to remember the details of events, such as accident and crimes, which they themselves have observed.
accuracy of EWT can be affected by factors such as misleading information, post event discussion and anxiety.
what is misleading information?
incorrect information given to a witness usually after the event. it can take many forms, such as leading questions and post-event discussion between other witnesses.
what is leading questions?
a question which, due to the way it is phrased, suggests a certain answer. for example, ‘was the knife in his left hand?’ - leads a person to think that’s where the knife was.
what is post-event discussion?
occurs when there is more than one witness to an event. witnesses may discuss what they have seen with co witnesses or with other people. this may influence the accuracy of each witness’ recall of the event.
who conducted research into leading questions?
Loftus and Palmer (1974).
what was the aim of the research by Loftus and Palmer (1974)?
to investigate the effect of leading questions on memory of an event.
describe the research conducted by Loftus and Palmer (1974) into leading questions.
arranged for 45 students to watch film clips of car accidents and then asked them questions about the accident.
in the leading question ptps 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 ptps and each group was given a different verb in the critical question - one group had the verb hit, the others had contacted, bumped, collided and smashed.
the mean estimated speed was calculated for each ptp group. the verb contacted resulted in a mean speed of 31.8mph. for the verb smashed, the mean was 40.5 mph. the leading question biased the eyewitnesses recall of an event.
discuss why leading questions effect EWT.
(response-bias explanation)
(substitution explanation)
the response-bias explanation suggests that the wording of the question has no real effect on the ptps memories, but just influences how they decide to answer. when a ptps 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 ptps memory of the film clip. this was shown because the ptps who originally heard smashed were later more likely to report seeing broken glass (there was none) than those who heard hit. the critical verb altered their memory of the incident.
what are some limitations of the research by Loftus and Palmer (1974)?
low ecological - lab experiment. artificial.
demand characteristics - ptps could’ve guessed the aim, and answered as they thought the researcher wanted.
who conducted research into post event discussion?
Gabbert et al (2003).
describe the research by Gabbert et al (2003).
studied ptps in pairs. each ptp watched a video of the same crime, but filmed from different points of view. this meant that each ptp could see elements in the event that the other could not. for example, only one of the ptps could see the title of a book being carried by a woman.
both ptps then discussed what they had seen before individually completing a test of recall.
the researchers found that 71% of the ptps 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, with no discussion, was 0%.
this was evidence of memory conformity.
discuss why post event discussion affects EWT.
memory contamination - when co-witnesses to a crime discuss it with each other, their EWT may become altered or distorted. this is because they combine information from other witnesses with their own.
memory conformity - witnesses often go along with each other, either to win social approval or they believe the other witnesses are right and they are wrong. unlike with memory contamination, the actual memory is unchanged. (supported by Gabbert et al).
discuss real world application as a strength of research into misleading info as a factor affecting EWT.
one strength is real world application to the criminal justice system.
inaccurate EWT can have serious consequences. leading questions can have a distorting effect on memory, so police officers need to be very careful about phrasing their questions when interviewing eyewitnesses. psychologists are sometimes asked to act as expert witnesses in court trials and explain the limits of EWT to juries.
this shows that psychologists can help to improve the way the legal system works, especially by protecting innocent people from faulty convictions based on unreliable EWT.
however, the practical applications of EWT may be affected by issues with the research. Loftus and Palmers ptps watched film clips in a lab, which is a very different experience from witnessing a real event (e.g. less stressful).
also, what eyewitnesses remember has important consequences in the real world, but ptps responses in research do not matter in the same way, so ptps feel less motivated to be accurate.
this suggests that researchers such as Loftus and Palmer are too pessimistic about the effects of misleading information - EWT may be more dependable than the studies suggest.
