Memory - Eyewitness Testimony Flashcards
Define eyewitness testimony
What does it include
Influence?
Eyewitness testimony (EWT) is the evidence supplied to a court by people who have seen a crime, based on their memory of the incident. This evidence can include an identification of the perpetrator or details of the crime (sequence of events, the time of day etc.). Juries are often heavily influenced by eyewitnesses.
Define leading questions
What do different explanations say about it?
Leading questions are questions that are phrased in such a way as to encourage a witness to give a certain answer. The response-bias explanation argues that leading questions do not affect memory, merely the answer a person chooses to give. However, the substitution-bias explanation proposes that leading questions distort memories because they contain misleading information.
Describe the procedure of the study related to leading questions
Procedure - Loftus and Palmer (1974) showed 45 American students a film of a car crash and then asked them to estimate the speed that the cars were travelling when they crashed. However different verbs were used in the question depending on the condition. The verbs were contacted, hit, bumped, collided, or smashed.
Describe the findings of the study related to leading questions
Findings - Participants in the ‘contacted’ condition estimated the speed as 31mph but in the ‘smashed’ condition participants estimated the speed as 41mph.
A week later participants were asked if they saw any broken glass, even though there was no broken glass shown in the film. 32% of the participants in the ‘smashed’ condition reported seeing broken glass compared to only 12% in the control condition.
This shows that leading questions have a significant impact on what people recall and can change a person’s entire memory of an event.
Evaluate leading questions
+ This study is a laboratory experiment and was therefore highly controlled. This reduces the chance of extraneous variables, increasing the validity of the results. Furthermore, it is easy for psychologists to replicate their research study to see if the same results are found, meaning the study is reliable.
- This study has questionable ecological validity. The participants watched a video of a car crash. People who witness a real car accident, who have a stronger emotionally connection to the event, may not be as susceptible to leading questions.
- This study lacks population validity. The study consisted of 45 American students. Students are less experienced drivers = less competent at estimating speeds. Consequently, we are unable to generalise the results of this study to other populations. Older and more experienced drivers may be more accurate in their judgement of speeds and therefore less susceptible to leading questions.
Describe post-event discussion
Can be caused by…
The memory of an event can be contaminated through discussing events with others due to misinformation (memory contamination). Also, a desire for social approval can lead co-witnesses to reach a consensus view of what happened (memory conformity)
Describe the procedure for the study relating to post-event discussion
Procedure - Gabbert et al. (2003) put participants in pairs and got them to watch a different video of the same event so that they each got unique details.
In one condition the pairs were encouraged to discuss the event with one another before individually recalling the event. In the other condition they did not discuss what they had seen with one another.
Describe the findings for the study relating to post-event discussion
Findings - 71% of witnesses who had discussed the event went on to mistakenly recall details that they could not have seen themselves, but that they had learned of during the discussion with their partner.
Evaluate post-event discussion
+ This study has population validity. Two different populations, students and older adults, were compared and there were no significant differences between these two groups. This allows us to conclude that post-event discussion affects younger and older adults in a similar way.
- This study lacks ecological validity. The participants knew they were taking part in an experiment and they therefore are more likely to have paid close attention to the details of the video clip. The results do not reflect real life where witnesses may be exposed to less information.
Describe anxiety and it’s impact regarding eyewitness testimony
Anxiety is a state of apprehension, uncertainty, and fear resulting from a threatening situation. When anxiety is high it can often impair both physical and psychological functioning. Several psychologists have suggested that the anxiety that occurs when witnessing a crime can prevent accurate and detailed recall of that crime.
What can increase anxiety (eyewitness testimony)
What effect is this
The presence of a weapon during a crime increases anxiety and therefore could impair witnesses’ memory of the crime. People who observe a violent crime will often pay attention to the aspect of the situation posing the most threat to them because of the anxiety these weapons cause. This means that witnesses who see a violent crime involving a weapon can often describe a criminal’s weapon in great detail, but they cannot recall much about the criminal themselves. This is called the weapon focus effect.
What are some factors which can impact the accuracy of eyewitness testimony
Anxiety
Weapon focus effect
Leading questions
Post-event discussion
Describe the procedure of the study related to anxiety and eyewitness testimony
Procedure – Loftus (1979) wanted to see whether anxiety affected a person’s ability to recognise the perpetrator of a crime.
- In the experimental condition Loftus arranged for participants to overhear a heated and hostile argument between two people. They also heard the sounds of furniture being overturned and broken glass.
- Then a man emerged carrying a letter opener covered in blood.
- In the control condition participants overheard a conversation between two people about laboratory equipment failure before a man with grease all over hishands emerged carrying a pen.
- Participants were then asked to identify the person they had just seen from 50 photos.
Describe the findings of the study related to anxiety and eyewitness testimony
Findings - Only 33% of the participants in the bloody letter opener condition recognised the photo of the person carrying the letter opener whereas 49% of the participants in the pen condition recognised the photo of the person carrying the pen.
- Loftus (1979) argued that this occurred because people in the former condition had focused on the bloody letter opener rather than the person carrying it, because the letter opener was a weapon that could pose a threat to them.
(Very detailed) evaluate anxiety in eyewitness testimony
+ This study is supported by other research studies. Loftus & Burns (1982) allocated participants into 1/2 conditions. One group watched a violent short film where a boy was shot in the head. The other group watched a non-violent short film of a crime. Participants were less accurate in recall when they saw the short film with a gun than those who watched the non-violent movie.
- lacks ecological validity. Although they were waiting in the reception area outside of the lab, they may have anticipated something was going to happen, which could have affected the accuracy of their judgements and the validity of the study.
- This study violated numerous ethical guidelines. Participants were deceived about the nature of the experiment and were not protected from psychological harm. The participants were exposed to a man who they believed had just killed someone, holding a bloodied knife, which could have caused them extreme distress. Participants may have left the experiment feeling exceptionally stressed, especially if they, or someone they knew, had been involved in knife crime.
- Yuille and Cutshall (1986) investigated the effect of anxiety in a real life shooting, in which one person was killed and another person seriously wounded. 21 witnesses were originally interviewed by investigating police and 13 of these witnesses, aged between 15 and 32, agreed to take part in Yuille and Cutshall’s follow-up interview five months later. The witnesses were accurate in their eyewitness accounts five months later and little change was found in their testimony. Furthermore, the witnesses avoided leading questions and those who had been most distressed at the time of the shooting gave the most accurate account. In real life cases leading questions and anxiety do not affect the accuracy of eyewitness testimony the same way they do in the laboratory.
- There are individual differences in how anxiety affects memory. Some people have better recall when they are anxious. Christianson and Hubinette (1983) conducted a research study using 110 real life eyewitnesses who had witnessed 1 of 22 bank robberies. There were onlookers and bank clerks who had been directly threatened by the robbers. Victims were more accurate than onlookers in their description of the bank robbers