Factors affecting the accuracy of Eye Witness Testimony Flashcards
Eyewitness Testimony (EWT)
Legal term. Evidence provided in court by a person who was present at the time a crime took place.
What are two factors that affect Eyewitness Testimony.
Misleading information (leading questions and post event discussion) and anxiety.
Misleading information
Incorrect information given to the eyewitness usually after the event has taken place. This can be in the form of leading questions or post event discussion.
What did Loftus and Palmer aim to investigate?
the effects of misleading information (in the form of leading questions) on the accuracy of eyewitness testimony.
What method did Loftus and Palmer use to investigate the effects of leading questions?
Took place in a lab with 45 students. They were each shown 7 films of different car accidents. Participants were given a questionnaire to describe the the accident. This included a CRITICAL question about ‘how fast were the cars going when they ‘HIT’ each other? Other groups ‘hit’ would be replaced by ‘smashed’ ‘collided’ or ‘contacted’. The mean speeds were then calculated for each condition.
What was the mean score for ‘smashed’?
40.8 mph
What was the mean score for ‘collided’?
39.3 mph
What was the mean score for ‘bumped’?
38.1 mph
What was the mean score for ‘hit’?
34 mph
What was the mean score for ‘contacted’?
31.8 mph
What did Loftus and palmer find in their study on leading questions?
REWORD THIS QUESTION
It was concluded that misleading information in the form of leading questions can indeed affect the accuracy of eyewitness testimony and that it may even cause the information to be changed before it was stored so that memory is permanently affected.
Strength of leading question research: high degree of control over variables
This means that the study was conducted in the controlled environment of a laboratory, all potential extraneous variables could be easily controlled. For example, Loftus and palmer could ensure lighting and noise levels whilst viewing the films was the same. This is a strength because it gives the research high internal validity meaning the experiment will have measured what it intended to measure.
Strength of leading question research: Loftus and palmer’s findings have practical applications
This means that the findings may be used to warn the criminal justice system about the potential problems with eyewitness evidence.
For example, juries could be warned against fully trusting evidence given by an eyewitness, however the eyewitness may be, and take into account more of a range of evidence when making decisions. This is positive as it may help to avoid inaccurate judgements being made in court.
Weakness of leading question research: using students as a sample may be unrepresentative.
This means that all of the participants in the research were one the of person who are not generally representative of the population. For example, students may be of above average intelligence.
This is problematic as the results could be said to lack ‘population’ validity as the findings cannot be generalised to everyone in society.
Weakness of leading question research: Research lacked ecological validity
This means that the study is conducted in the controlled setting of a lab and this does not reflect EWT in real life.
For example, the studies do not represent the experience of witnessing a realise car accident in the street and may also lack the fear or emotion present in eyewitness events of this kind.
This is a problem as the findings cannot be generalised to real life settings and real life EWT.
Weakness of leading question research: Yuille and cutshall 1986
It was found that 4 months after a real life robbery in Canada the 13 witnesses were not affected by two leading questions and gave the same respeonces they had given in their initial reports straight after the robbery.
It was concluded that misleading information does not affect real life EWT, possibly due to the level of anxiety and emotion experienced in real life.
This is a problem because it adds further weight to the view that Loftus and Palmer’s findings do not generalise to real-life EWT because the lab conditions lack the emotion of real life EWT.
What did Gabbert et al aim to investigate
Test the effects of post event discussion has on the accuracy of EWT.
What method did Gabbert et al use to investigate the effects of post event discussion?
- 120 participants in pairs
- Shown the same video from different POV meaning each could see different elements of the video
- For example one could see the title and one could see her commit a crime
- Then both discussed what they had seen
How many participants mistakenly reported aspects of the video that didn’t actually take place?
71%
How many participants reported the crime which they didn’t see take place?
60%
What did Gabbert et al conclude?
Witnesses often go along with each other due to MEMORY CONFORMITY - going along with the testimony of others either to win their social approval or because they believe the other witnesses are right and they are wrong.
What percentage of participants in the control group mistakenly recalled information?
0%
Strength of research into post event discussion: easy to replicate
This means that the study was conducted in the controlled environment of of a laboratory, using a video of a crime, it is easy to repeat the study in the same way over and over again.
For example, Gabbert et al could show the same video in the same conditions.
This is positive as it means the findings can easily b tested for reliability (ie consistency)
Strength of research into post event discussion: Bodner et al
They found similarly strong effects of post event discussion on the accuracy of EWT. However they also found that these effects could be reduced if participants could be warned about the negative effects of listening to second hand information from other witnesses.
This is positive because it supports the idea that memory conformity has a strong influence on EWT. accuracy.
Strength of research into post event discussion: it has real world applications.
This means that the findings may be used to warn eyewitnesses about ‘second hand information’ from other witnesses to reduce these problems.
For example, before giving evidence eyewitnesses can be warned about how memory conformity can occur and can unfairly influence the justice process.
This is positive as as it may help to avoid inaccurate judgements being made in court.
Weakness of research into post event discussion: research involving ‘mock crimes’ is that they lack the consequences of real life crime.
This means that participants are aware that the information they give doesn’t have such serious consequences as it would for an eyewitness in real life where the information they give can lead to people being wrongly sent to prison or set free.
For example, participants might be less likely to say that saw the girl in the video commit a crime if they had seen in real life and their testimony could have a real damaging effect on her life.
This is a problem as the findings may not accurately represent real life EWT.
Strengths of research into post event discussion: Positive effect on the economy.
This means that by developing strategies to combat the effects of post-event discussion as well as leading questions, this should help improve efficiency in the legal system.
For example, by allowing police to spend less time and money investigating inaccurate claims.
This is positive as it helps to reduce waste in the legal system.
Anxiety
A state of emotional and physical arousal.
Weapon-focus effect
Presence of a weapon increases anxiety so the victim focuses on central rather than peripheral details. Can struggle to recall key details of what they saw. this makes EWT less accurate.
Who conducted research into anxiety?
Johnson and Scott
What did Johnson and Scott aim to investigate?
Aimed to study the effects of anxiety caused by a weapon being present on the accuracy of EWT.
What did Johnson and Scott do?
- Lab experiment which was split into 2 conditions
- Each were instructed to wait outside a room.
- Both groups heard a discussion in a neighbouring room
- Group 1 a man came out of the room holding a pen with grease covering his hands
- Group 2, the discussion was more hated an the man came out with a letter opener covered in blood (a weapon)
- The participants were then asked to identify the man from 50 photographs
What percentage of people accurately identified the man in condition 1? (pen and grease)
49%
What percentage of people accurately identified the man in condition 2? (knife and blood)
33%
What did Johnson and Scott conclude?
Anxiety caused by the weapon narrowed the focus of attention making their recall less detailed and accurate which may explain why eyewitnesses sometimes have poor recall for certain violent crimes.
Strength of research into the effects of anxiety on EWT: High degree of control variables
This means that because the study was conducted in the controlled environment of a lab, all potential extraneous variables could easily be controlled.
For example, the man who appeared from the room and photos could be standardised for each trial.
This is a strength because it gives the research high internal validity meaning that it measured what it intended to measure.
Weakness of research into the effects of anxiety on EWT: Suffers from ethical issues
This means that Johnson and Scott may have failed to protect their participants from harm. For example, exposing participants to a traumatic event such as seeing a man holding a knife covered in blood might have caused participants lasting harm.
This is a problem as it goes against the ethical code of conduct.
Strength of research into the effects of anxiety on EWT: Loftus et al
It was found that the presence of a weapon caused eye movements to be drawn towards the weapon itself and away from other things such as the persons face.
It was concluded anxiety caused by the weapon can therefore affect the focus of attention.
This is positive as it supports Johnson and scotts finding that anxiety is caused by weapons decreases eyewitness accuracy and helps explain why this is - due to a shift in our visual attention.
Weakness of research into the effects of anxiety on EWT: Anxiety can actually improve EWT
Christian and Hubinette found that out of 58 real witnesses to bank robberies who had been directly threatened in some way during the robbery, were actually more accurate in their recall. Some recalled more details than those that had not been directly threatened. (therefore less emotionally aroused and less anxious).
this is problematic as it suggests that Johnson and Scotts findings were incorrect and the anxiety may actually increase the accuracy.
Strength of research into the effects of anxiety on EWT: Evidence to explain the contradiction between Johnson and Scott and anxiety.
Dodson law states that anxiety can help improve EWT up to an ‘optimal point’ and after this, too much anxiety can reduce the accuracy of EWT. It could be concluded that Johnson and Scott’s weapons focus research where the presence of a weapon reduced the accuracy occurred because anxiety levels were higher than the optimal point in the weapon condition therefore it began to decrease the accuracy of EWT.
This may be seen as supporting Johnson and Scotts research whilst also explaining why other studies into anxiety have not always shown anxiety reduces EWT accuracy.
Cognitive Interview (CI)
A method of interviewing eyewitnesses with aims to help achieve a more accurate eyewitness testimony.
What does a standard police interview entail?
Witnesses are often interrupted and are not allowed to talk freely. They use closed questions and encourage shorter answers.
Who came up with cognitive interview?
Fisher and Geisleman
What does the cognitive interview aim to do?
Encourage the eyewitness to recall more information.
What are the names of the 4 techniques of the CI?
- Context Reinstatement CR
- Report everything RE
- Changing the Perspective CP
- Reverse the order RO
Context reinstatement
Imagine themselves back at the scene of the crime. They could ask how they were feeling at the time to try to recreate the feeling. This provides retrieval cues.
