* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Eyewitness Testimony - a2 Psychology Lesson updates 13-14
Survey
Document related concepts
Transcript
Eye Witness Testimony EWT Eye Witness Testimony -1 AO1 - outline what is meant by the terms EWT and Leading questions A01/2 -Discuss the factors that affect the accuracy of EWT (leading questions, anxiety, age of witness) Evaluate the impact of misleading information on EWT Eyewitness Testimony Reconstructive memory Schema driven errors Effect of leading questions Other factors Weapon focus Effects of anxiety/arousal Age of witness www.psychlotron.org.uk Reconstructive Memory Bartlett (1932) Memory is not a direct record of what was witnessed What is encoded and how it is retrieved depends on: Information already stored in memory How this info is understood, structured and organised www.psychlotron.org.uk Reconstructive Memory Schemas Knowledge structures that relate to commonly encountered objects, situations or people Enable us to predict events, make sense of unfamiliar circumstances, organise our own behaviour Act as filters to perception & recall www.psychlotron.org.uk Computer Information Processing BANG! www.psychlotron.org.uk Can you wreck a nice beach? Schema Driven Processing Yes. I can recognise speech. www.psychlotron.org.uk Can you wreck a nice beach? Bartlett (1932) Input Schema Output ‘Turf cutter’ Bartlett (1932) See also Carmichael et al (32) p 32 Exploring Psychology www.psychlotron.org.uk ‘Pickaxe’ EWT: Schema Driven Errors Witnesses to crimes filter information during acquisition & recall Their schematic understanding may influence how info is both stored & retrieved Distortions may occur without the witness realising www.psychlotron.org.uk Past experiences Assumptions about what usually happens Stereotypes & beliefs about crime & criminals www.psychlotron.org.uk EWT: Schema Driven Errors Look at this picture Write down a description of what is happening in the picture Factors that affect Eye Witness Testimony Stereotypes - Allport and Postman (1947) Participants shown a cartoon of a black and a white man on a subway train. Most recalled that the black man had the razor in his hand. The razor was actually in the white man’s hand. (stereotype – more prone to violence). Conclusion: When an actual perceptual fact doesn’t match our expectations, we trust our expectation more than the real situation. We see what we expect to see and this forms the basis for the memory for an event. EWT: Leading Questions Loftus (1970s onwards) Effect of leading questions on recall Leading questions introduce new information Leading info may activate wrong schemas in witness’ mind Consequently, witness may recall events incorrectly www.psychlotron.org.uk Factors that affect reconstructive memory How witnesses are interviewed – leading questions, facial techniques, tone of voice of interview may unintentionally communicate their expectations (what they want to hear). Eye Witness Testimony Elizabeth Loftus (70’s) Research) Illustrated the reconstructive nature of memory. Star Study: Loftus and Palmer (1974) http://www.youtube.com/watch?v=8hwEUaOeuFQ The role of misleading questions? In her research Loftus showed that memories can be affected by the wording of questions. A leading question is a question about an event that is phrased in such a way as to prompt a particular answer. Information is provided in the question (i.e. after the event) which may distort the accuracy of the memory. Do people believe EWT’s? Loftus (1974) shows that people tend to believe a suspect is guilty if there is an eyewitness. So it is very important that psychologists find out why EWT is inaccurate and how to improve accuracy. Loftus and Palmer (74) Read about this classic research in your text book Draw a graph of the results What conclusion can be drawn from this research? What does is suggest about the accuracy of EWT? Any problems with this piece of research? EWT: Leading Questions Loftus’ studies using film/video/slides road accidents ‘How fast were cars going when they hit…’ or ‘…when they smashed…’? ‘Smashed’ led to higher speed estimates Loftus and Zanni (1975) ‘Did you see a/the broken headlight’? ‘The’ produced more affirmative (incorrect) responses www.psychlotron.org.uk EWT: Leading Questions Loftus’ research usually lab based: Restricted samples (students) Artificial stimuli (slides, videos, not real events) Potential for demand characteristics to influence responses No legal/moral consequences for inaccurate answers. (Foster et al (1994) – witnesses more accurate in recalling memory of a bank robbery when they were led to believe their testimony would influence a real trial.) www.psychlotron.org.uk What other factors affect Eye Witness Testimony? Anxiety If you were a witness to a crime: How would you feel? What other factors affect Eye Witness Testimony? Age of witness Can we rely on the testimony of children and older people? How does anxiety and age of witness affect EWT? Over to you….. You will be given one of the above to research using the text book. Produce a bullet point summary to report your findings back to the other group. When a weapon is used to threaten a victim, their attention is likely to focus on it Consequently, their recall of other information is likely to be poor www.psychlotron.org.uk Anxiety: Weapon Focus performance arousal Graph to show the YerkesDodson Law that says that performance is best in moderately arousing conditions Memory is most effective at moderate arousal levels If the witness was in a state of extremely low or high arousal then recall may be poor www.psychlotron.org.uk EWT: Arousal Effects Yuille and Cutshall (86) Assessed level of arousal and accuracy of testimonies from 13 witnesses to real robberies or murders. Less accurate recall when levels of arousal were high than low, BUT very high arousal led to better recall than moderate. Does not match Yerkes-Dodson Law Could be explained by how close (proximity) witnesses were to the crime Closest are more stressed, but have better view Freud (1894) Repression – motivated forgetting Traumatic memories become inaccessible (in unconscious) to protect us from being upset by them. Conflicting evidence for this theory See p 31 Exploring Psychology Age of Witness and EWT Children Brennan and Brennan (88) 6-15 year olds failed to understand 1/3 of questions asked by lawyers. More correct answers when asked more simple questions (Carter et al 96) ‘Tags’ – ‘didn’t she’ added at end – led to more yes answers than when tag not there (Krackow and Lynn 03) Age of Witness and EWT Children – Children often change answers if question repeated. (Samuel and Bryant, 84. Blades and Krahenbuhl, 06) Memon et al (06) – positive, but not negative stereotypes affect children’s judgements about people. Defendents with more positive stereotype less likely to considered guilty. Age of Witness and EWT Thinking Critically about psychology p 36 How does Memon et al’s research findings help to explain why Ian Huntley was able to get away with the crime for so long? When he was interviewed Ian Huntley (2003) on TV at the time of the Soham murders murder he wasn’t considered a suspect Age of Witness and EWT Older Adults as Witnesses Assumption by police and society that Memory fails with age, so less reliable Eye witnesses. Backed up by: (Holliday, ‘05), Brimacombe et al (‘97), Wright and Holliday (’07) Age of witness made no difference in cognitive interviews (next lesson!!) Plenary 1. 2. 3. Answer the following questions What type of experiments were those carried out by Loftus in the 70’s? What are the strengths and weaknesses of her research? Find examples of ethical issues raised during EWT research. How could they be addressed? Homework Summarise the work you have covered today as bullet points of the main points or a mind map. Include – Definition of leading questions, EWT, weapon focus, Yerkes-Dodson Law - The research of Loftus – (1974), Loftus and Zanni and Yuille and Cutshall (pros and cons, ethics e.t.c) - the affect of leading questions, age and anxiety on EWT Finish the Case of Wrongful Conviction activity What does this task highlight about the impact of misleading info, age and anxiety on EWT? Eye Witness Testimony AO1 - Describe the cognitive interview technique and understand its rationale A01/2 - Describe and evaluate evidence that underpins our understanding of EW AO2 - Discuss the impact of misleading information on EWT The Cognitive Interview In the light of the work of Loftus on the importance of Leading Questions in the 70’s Police needed to change questioning techniques. The Cognitive Interview Also EWT typically takes place in a different context to acquisition (scene of the crime) Lack of retrieval cues (state and context) can inhibit recall Reconstruction of the events (either imagination or simulation) can lead to enhanced recall This is one of the elements of the Cognitive Interview The Cognitive Interview Geiselman et al (1985) identified 4 key principles for the cognitive interview. In pairs use p 37 of Exploring Psychology and p14 of your revision guide to find out what those 4 key principles are, plus the principles of the Enhanced CI (Fisher et a, ’87) Each study 4 and report back to your partner. Fill in the worksheet, use as a revision tool. The Cognitive Interview Try it for yourself…. Work in fours – 2 of you will be the interviewers and the other 2 the witnesses Use the incident from the video Either ask direct ’interrogative’ questions (see sheet) Or Use a Cognitive interview technique (see sheet) Compare the accuracy of the recall. The Cognitive Interview Outline the pros and cons of the CI, using research studies – Fisher et al (87) Geiselman (86) – Geiselman and Fisher (97) The Cognitive Interview Pros – lots of studies (in real and lab situations) have shown that CI produce more forensically rich information . Cons – Can be time consuming – some elements missed out (Thames Valley Police) - Insufficient training (Memon et al 94) Plenary Think LoP Create a poster, leaflet, or mind map of what you have learnt about what factors can affect Eye Witness Testimony and recommendations for how best to make EWT testimonies as accurate as possible. Think about your audience. Select the most important points. Have a balanced view.