Presentation on theme: "EWT YoMvyrDsJo. What it is? Eyewitness testimony is the memory of an incident or event from someone who was actually."— Presentation transcript:
What it is? Eyewitness testimony is the memory of an incident or event from someone who was actually there at the time. Last lesson Friday pupils to wear mufti.
Exam board Eyewitness testimony (EWT). Factors affecting the accuracy of EWT, including misleading information, anxiety, age of witness.
Loftus Watch the video of Loftus in Scotland. What did she find: That we can influence the memory of EW by the language we use. Watch second Video. So we can see that misleading questioning can lead inaccurate recall (memory).
Study of misleading Information Loftus and Palmer (1974) Participants watch a video of a car accident. The they are asked the question to estimate the speed. One group is asked “ How fast were the cars going when they connected” Guess: 31.8 The other “How fast were they going when they smashed into each other” Guess: 41.8
These results showed that dependent on how the question was asked effected the answer. It was a lab experiment and so not real life and a traumatic event may give better memory.
The effect of leading questions Loftus & Palmer (1974) The aim of this study was to investigate the effect of leading verbs on eye witness accounts of a car crash. All participants watched a film in which two cars crashed in to each other. They were then randomly allocated to one of five groups and asked to answer some questions about the film. Each group had one question that differed slightly over the five conditions of the experiment, “About how fast were the cars going when they collided with each other?” (The important verb in the question was changed to either contacted, collided, smashed, hit or bumped.) In the ‘smashed’ condition participants gave a significantly higher speed estimate (40.8 mph) compared with the contacted, collided, hit and bumped conditions (31.8, 34.2, 38.1 and 39.3 mph respectively). This showed that the type of question an eyewitness is asked can have a distorting effect on their memory of an incident. In this case the verb used in the question led participants into making a different type of speed estimate.
Loftus & Palmer followed also wanted to investigate just how widely the type of questioning asked could affect participants’ memories of an incident. They followed their initial study with a second one in which participants were asked the same leading questions again (this time only hit and smashed were used, and there was also a control condition with no speed related question) but were also asked whether or not they had seen any broken glass. “Was there any broken glass at the scene?” 47% of participants in the ‘smashed’ condition reported seeing broken glass compared with 16% in the ‘hit’ condition and 13.5% in the control condition. There had in fact been no broken glass in the film scene, but participants’ memories were again led into incorrect recall by the simple verb they were asked. This shows that an eyewitness can be led into providing incorrect recall of events by the type of questions asked related to the event. As this was a laboratory experiment Loftus & Palmer were able to establish an extremely strong causal link between their independent variable (the verb used) and their dependent variable (the answers participants gave to the questions), and could be relatively certain that most if not all extraneous variables were controlled for. However laboratory experiments lack ecological validity, and this particular study does not fairly represent events in real life as a real life incident would probably be witnessed directly and without warning, and not on a film clip in a comfortable laboratory. The participants used in the study were all American university students which means that the results lack population validity outside that of American university students, in other words they cannot be generalised to the majority of people in the world.
The effect of misleading information Misleading information, also known as after the fact information, can change the memory of an eyewitness by providing information that becomes incorporated in to the memory of the event even though it was not present at the time of the event. Loftus (1975) Loftus demonstrated the power of misleading information in a laboratory experiment in which participants were shown a film clip of a car accident. After watching the film participants were asked either, “How fast was the white sports car going when it passed the barn while traveling along the country road?” (the barn condition) or “How fast was the white sports car going while traveling along the country road?” (the control condition). “Did you see a barn?” Even though there was no barn in the film clip, over 17% of participants in the barn condition claimed one week later that they had seen a barn compared with only 3% in the control condition. The simple question about how far the car was travelling when it passed the barn was enough to add a barn to memories of 17% of the participants in the study. It is not hard therefore to see how a question that adds new information may change the memory of a witness to a crime! As with all laboratory experiments, there was good control of extraneous variables which allows a causal link to be established between the question type and the answers participants gave to the questions. The study was however low in ecological validity as the task was unrepresentative of everyday events (i.e. a film rather than a real life incident), and it was low in population validity as the participants were all American college students.
“Did you see a barn?” Even though there was no barn in the film clip, over 17% of participants in the barn condition claimed one week later that they had seen a barn compared with only 3% in the control condition. The simple question about how far the car was travelling when it passed the barn was enough to add a barn to memories of 17% of the participants in the study. It is not hard therefore to see how a question that adds new information may change the memory of a witness to a crime! As with all laboratory experiments, there was good control of extraneous variables which allows a causal link to be established between the question type and the answers participants gave to the questions. The study was however low in ecological validity as the task was unrepresentative of everyday events (i.e. a film rather than a real life incident), and it was low in population validity as the participants were all American college students. Part 2 of video
What about blatantly incorrect information? When misleading information is provided that is blatantly incorrect, witnesses are generally more resistant to being misled and tend to stick to the events they remember witnessing. Loftus (1975) showed participants a set of slides of a handbag robbery. Immediately after seeing the slides participants were asked what the colour of the handbag was, with the result that 98% correctly answered that it was a red handbag. Participants then read an account given by a professor of psychology who witnessed the incident - one version of the witness account had many minor incorrect facts and the another version stated that a brown handbag had been stolen. Almost all of the participants who read the brown handbag account resisted the incorrect information and stuck to their memories of a red handbag.
A Level exam tips Answering a 12 mark question (PSYA1 AQA A specification) Outline and evaluate research into the effects of misleading information on eyewitness testimony. 6 AO1 marks - describe the research. This page details a study by Loftus & Palmer (1974) into leading questions, a study by Loftus (1975) into misleading after the fact information, and a study by Loftus 91975) into blatantly incorrect information. 6AO2 marks come from evaluating the research. Discuss the studies in terms of them being laboratory experiments that have the strengths of control of extraneous variables and good causal inference, but the weaknesses of low ecological validity and low population validity. Explain why these are strengths or weaknesses for the studies.
Essay Describe One study of the effects of misleading information on eyewitness testimony. (6) Explain one problem with the validity of the study described in the above question (3)
The effect of anxiety on eyewitness testimony How does a stressful situation, such as the presence of a weapon, affect the accuracy of eyewitness memory? Is there a difference between laboratory and real life studies of anxiety in EWT? What do you think! Discussion
Anxiety and cognitive performance Inverted U theory (Deffenbacher, 1983) Inverted U theory states that at low levels of anxiety cognitive performance (in this case memory accuracy) will be at a relatively low level, but as anxiety increases then so does cognitive performance until it reaches an optimal level after which any further increase in anxiety level leads to a rapid drop in cognitive performance. You may recognise this from sports as it is the theory for arousal at an event. That is your performance dips if over anxious.
If we apply this theory to eyewitness testimony we can predict that stressful incidents, such as being a victim or witness to a crime, will lead to witnesses having relatively inaccurate memories of the event as their anxiety levels at the time would have been above the optimal level.
Peters (1988) Peters (1988) found that participants who received an inoculation showed impaired eyewitness identification and recollection of the appearance of the nurse who gave the injection, in comparison to a researcher with whom they interacted for a similar length of time a few minutes after the receiving the injection. The effect was stronger for participants who showed greater physiological activation whilst waiting for their inoculation.
Weapon focus Participants in this study were left in a waiting area outside a laboratory whilst waiting for the “real” study to start. While they were waiting one of two situations occurred. In the first situation they overheard a discussion in the laboratory about equipment failure, followed by a man leaving the laboratory holding a pen and with grease on his hands. In the second situation participants overheard a heated discussion in the laboratory with the sound of breaking glass and crashing chairs, followed by a man leaving the laboratory carrying a paper knife covered in blood. The participants were later asked to identify the man from a set of 50 photographs with the result that 49% correctly identified the man holding the pen, but only 33% could identify the man with the blood stained knife. Loftus argued that participants were less able to correctly recall the man with the knife because they had their attention absorbed by the knife (presumably because it was potentially a source of danger to them), and so were distracted from the appearance of the man holding it. This has become known as weapon focus and explains how witnesses to violent crimes may accurately recall central details (e.g. the type of weapon and what was done with it), but may be less accurate at recalling periphery details such as the appearance or clothing of a criminal.
Yuille & Cutshall (1986) Yuille & Cutshall interviewed 13 witnesses to a real life shooting in which a storeowner in America was injured and the thief was shot dead. Some of the witnesses had been very close to the incident whist others had viewed it from a distance away. The researchers found that the witnesses closest to the event gave the most detail, that all of the witnesses were able to give accurate accounts several months later, that they were seemingly unaffected by misleading questions, and that the witnesses that had been the most distressed at the time of the incident actually gave the most accurate testimony several months later.
Christianson & Hubinette (1993) 110 witnesses of 22 real life bank robberies were interviewed some time after the robberies. Some of the witnesses had been onlookers or customers in the bank, and others were bank employees who had been directly threatened or subjected to violence during the robberies. The findings were that the victims were surprisingly accurate in their recall of the robbers’ clothing and behaviour, and that the accuracy was still evident 15 months later. The results of these studies are surprising as they are completely opposite to those that inverted U theory and weapon focus would predict. The witnesses were neither so distressed that their cognitive performance was very low, nor was their attention overly absorbed by the presence of a weapon. But as it was an uncontrolled study then it could be that the witnesses had discussed the shooting so often, been interviewed so many times, and even read about the event in the newspapers that their memories may not be entirely their own. Which one do you think is correct?
The difference between laboratory and real world research into anxiety and eyewitness testimony READ Real world research into eyewitness testimony has a valuable advantage over laboratory research as it has very high ecological validity. In laboratory studies, participants are exposed to often unrealistic scenarios presented in an unrealistic way, and to a certain extent there are demand characteristics as they are expecting to be asked about the event they are shown. Real world events are sudden, unexpected, have high levels of emotion and stress involved, and provide the only real way to test how accurately witnesses recall events; however they are also uncontrolled and it is impossible to account for how witnesses may discuss the event with one another, are interviewed by authorities, and what they read before the researchers get the chance to interview them. Both laboratory and real life studies are therefore important, but it is very interesting how the methods provide contrasting results.
A Level exam tips Answering a 12 mark question (PSYA1 AQA A specification) Outline and evaluate research into the effect of anxiety on EWT AO1 marks would come from a description of relevant research studies. Choosing 3 studies, perhaps 1 lab study and 2 real life ones, and describing them in simple paragraphs would be sufficient. AO2 marks would then come from evaluating the studies and explaining what the evaluation means for the validity of the research. Focus on control of extraneous variables, cause and effect, ecological validity, and population validity or generalisabilty.
Question Describe one study of the effects of misleading information on Eyewitness testimony? (6) Outline and evaluate research on the effect of misleading information on eyewitness testimony (12) / /
The effect of age on eyewitness testimony Children are rubbish –they want to please. They want to answer the authority figure. A little more scientific: Kent & Yuille (1987) Kent & Yuille asked children to identify from a set of photographs a person they had seen earlier. They found that 9 year old children were far more likely than 14 year olds to identify someone from the photo set even when the target person was not present - in other words younger children were less likely to say that the person they had seen earlier was not present in the photo set. This followed earlier research that showed children as young as 5 were as able to correctly identify people they had seen earlier, and so it is not a problem with children’s memories that causes them to identify wrong people, but it is more likely that they feel less able to admit to an adult that they cannot do the task and so they just pick any photo when the target one is not there. Research into the accuracy of children as eyewitnesses by Geiselman & Padilla (1988) found that children were far less accurate when reporting events of a filmed bank robbery than adults, however other research has failed to find much of a difference between adults and children, especially when free recall rather than structured interview is used (e.g. Cassel et al, 1996).
Factors affecting the accuracy of children’s memories 1.Encoding: semantic for LT – not enough experience. 2.Storage: Children susceptible to decline 3.Retrieval: Children more susceptible to leading questions.
Research Roberts and Lamb - they analysed 161 police interviews with children regarding allegations of abuse. In 68 / 161 of the interviews the interviewer misinterpreted “in private” as “in the privates” and in 2/3 of these cases this remained uncorrected by the children. Therefore, this research would suggest that people of a young age do not have accurate eye witness testimony. Davies - found that differences between child and adult interviews were overstated and that children can provide very valuable eye witness testimony as long as care is taken during the interviewing procedure. Therefore, this research would suggest that people of a young age do have accurate eye witness testimony.
Old Age Cohen and Faulkner - they showed 70 year olds and 35 year olds a film of a kidnapping then presented them with misleading details before asking them to recall what happened in the film. They found that the 70 years olds were more likely to be mislead than the 35 years olds. Therefore, this research would suggest that people of an old age do not have accurate eye witness testimony. Coxon and Valentine - they asked children (aged 8 ), young adults (aged 17) and older adults (aged 70) questions containing misleading information after they had watched a video. They then asked a further 20 specific questions to assess whether they had accepted the misleading information or not. They found that the older adults were less suggestible and were the only age group not to show a statistically significant misinformation effect. Therefore, this research would suggest that people of an old age do have accurate eye witness testimony.
So. Strength / Weakness - most of the research is lab based meaning it is replicable and scientific but is lacking in ecological validity. Strength / Weakness - research that is in the form of naturally occurring phenomena (Roberts and Lamb) has good ecological validity but is not scientific or replicable as variables were not highly controlled and because it is not artificial. It would also be unethical to test eye witness testimony when a real sensitive subject is being discussed. Strength / Weakness - the results could be due to a number of factors such as: young people may be more used to memory tests or older adults have poorer health leading to memory impairment. Weakness - the research findings are inconclusive. Weakness - the factors given by researchers, such as the ones stated, are only assumptions with no scientific evidence. Weakness - the research over exaggerates how bad memory is. This could be due to the fact that it is being studied in lab conditions and only the short term effects of memory and eye witness testimony are being taken into account.
Questions The graph shows the relationship between anxiety and recall. What can you conclude from the graph? (4) Describe what research has shown about the effect of the age of a witness on the accuracy of eyewitness testimony. (6)
Cognitive Interview Rationale behind the cognitive interview As we have seen from research into the effects of misleading information, leading questions and age on eyewitness testimony, the memories eyewitnesses have for a crucial event can be extremely inaccurate. This seems to be because selecting information to store in long term memory is driven by schemas, encoding is based on meaning and is organised into schemas, and recall is reconstructive based on schemas that guide the eyewitness to recreating the event based on what they would expect to happen rather than what actually happened. The cognitive interview provides authorities with an interview technique that is less likely to activate schemas than a standard interview. Link Link
Gieselman et al (1985) The cognitive interview has four main techniques: 1. Report everything. Witnesses may omit details they feel are irrelevant, especially if they do not fit into their existing schemas for that type of event. Encouraging them to report every detail, no matter how small, can increase witness accuracy. 2. Reinstate the context at the time of the event. Encouraging witnesses to recall how they felt, the weather, smells, time of day etc helps put the person back in time to the incident and may improve recall accuracy. 3. Change the order in which the event is recalled. Recalling events in reverse order, or from the middle and working backwards and forwards in time, can interrupt schema activation, make it harder for the witness to reconstruct a story that makes sense, and improve eyewitness accuracy. 4. Change perspective. Trying to adopt the viewpoint of a different witness, e.g. a prominent character in the incident, can encourage recall of events that may otherwise be omitted.
Research Geiselman et al (1985) Geiselman et al compared their cognitive interview with a standard interview technique on 51 volunteer participants from a wide demographic background. Participants watched two films of violent crimes and 48 hours later were interviewed by trained police officers using either a standard interview or a cognitive interview. The results showed a significant increase in the number of correct items recalled using the cognitive interview, and a small decrease in the number of confabulated items (items of descriptions made up by participants to fit the story). This research was, of course, lacking in ecological validity as participants watched filmed incidents.
Research 2 Fisher et al (1989) This was a study of real life cognitive interview performance. The researchers trained police detectives in Florida in the use of the cognitive interview, and compared their interview performable before and after training. After training, the detectives gained as much as 47% more useful information from witnesses to real crimes compared to when they had been using standard interview techniques.
Other research Bekerian & Dennet (1993) reviewed 27 studies into the effectiveness of the cognitive interview schedule and found that the cognitive interview provided more accurate information than other interview techniques. Holliday (2003) showed children aged 5 to 9 a video of a child’s birthday party and interviewed them the next day using both cognitive and standard interview methods. They found that the cognitive interview yielded more correct details about the video than the standard interview, and so showed that it can also be very useful when interviewing children.
A Level exam tips Answering a 12 mark question (PSYA1 AQA A specification) Outline and evaluate the cognitive interview. 6 AO1 marks can be gained by introducing the cognitive interview as a tool to reduce schema activation and improve eyewitness accuracy, followed by an explanation of the 4 main techniques and examples of one or two of them. Some questions will be based on a scenario and so it is important to give examples that relate to that scenario. 6 AO2 marks will come from evaluating the effectiveness of the cognitive interview in comparison to a standard interview technique. Summarising and evaluating the research by Geiselman et al (1985), Fisher et al (1989), Bekerian & Dennet (1993), and Holliday (2003) will usually gain full marks.