Eye Witness Testimony Flashcards
Memory in everyday life.
Eyewitness testimony.
What is Eye Witness testimony?
Eye Witness testimony is the evidence collected from people who have witnessed a particular event or crime.
What is EWT?
- it is a legal term - evidence provided in court by a person
3 stages:
- Details of the event are encoded into LTM
- Witness retains info. For a period of time
- Witness retrieves memory from storage
Why is it important that we understand factors that may effect Eye Witness Testimony?
- In the USA around 200 people convicted of crimes have later been proven innocent following DNA evidence.
- More than 75% of them had been originally found guilty based on EWT
AGE and Eye Witness Testimony
- Valentine and Coxon
- Barlett
- Gross and Hayne
Valentine and Coxon - Studied ALL ages
- Children/young adults and elderly. Shown a video of kidnapping.
- The elderly and young children gave more incorrect info. Children were most affected by leading questions (possibly felt the pressure to believe interviewer)
- Lab experiment: children aren’t expecting to be decieved
Valentine and Coxon - BUT
Doubts have been expressed about the value of laboratory findings for eyewitness testimonies in the real world becuase it lacks ecological validity.
- In a Lab people are witnesses rather than victims, SO situations are less stressful
- And participants often only have a few seconds to rememberfaces (results may be less accurate)
- Thirdly, the Consequences of making a mistake are trivial
- Expecting your memory to be tested.
- Doesn’t matter of you make a mistake
Age of witness
- Pozzulo and Lindsay found that children under 5 were less likely than older children and adults to make correct identifications when the culprit was in a line up.
- Children over 5 performed as well as adults when the culprit was present
- BUT children under 12 were more likely to make a choice even when the culprit was not present!
- Suggesting children under 13 are effected by misleading information
Younger children are also more suggestible than older children.
- Bronfeenbrenner compared young children’s memory with older children’s memory and adults. Some were presented with misleading info
- Memory was only slightly affected by age but accuracy of memory was much worse in the younger children who had been given the misleading information.
Young children may produce distorted reports due to?
- Cognitive incompetence
- OR they may yield to social pressure
- They may be overconfident in their ability to make correct memory decisions
Gross and Hayne
argue that we can improve children’s memory by asking them to draw what they can remember (as their memories may be visual rather than in language form.)
Older (60%) Vs Younger Adults
- Older people have also found to be more likely to chose someone from a line-up when the culprit is not present and are strongly influenced by misleading information.
- Worryingly ( Dodson and Kruger) older adults were very confident about the correctness of their false memories
- This may be due to schemas
Bratlett 1932
claimed that our prior knowledge in the form of SCHEMAS influence what we remember and how we remember it
Older Adults
- Older adults may recall more inaccurate information due to the amount of experiences they have had and therefore the number of schemas that they have stored in their memory.
- Old schemas may be used, subconsciously, to fill in any gaps in their memories.
To improve the memory of older adults:
- It is very important that they are not exposed to anything that may distort their memories
- It is essential to engage in detailed questioning (as older adults often remember info that is genuine but applies to prior/previous situations)
More Evaluation
- When studying age, peoples’ memories have been found to be most effective when identifying someone of the same age (own age bias)
- Therefore all ages may perform poorly if the culprit that they have to identify is from a different age group
This is supported by Anatasi & Rhodes (2006)
- 3 groups
18-25 35-45 55-78 - Shown 24 photos representing different age groups which they had to rate for attractiveness
- After filler activity they were shown 48 photos
- 2 younger groups were significantly more accurate than the older group
- All were more accurrate at identifying photos from their own age group
Anxiety and Memory
ANXIETY
- Eyewitnesses (especially when victims) are often anxious when witnessing a crime due to fear.
We need to note that:
- Eyewitnesses remember attended aspects of the crime situation much better than non-attended aspects and some eyewitness may be more anxious by nature than others.
Eyewitnesses attend mainly to aspects if the crime that pose a threat to them:
- Weapon focus research has shown that in violent crimes ANXIETY means that witnesses pay particular attention to the weapon and not as much to the actual culprit.. BUT this may be because the weapon isn’t expected (and not due to anxiety)
LOFTUS provided supporting evidence that anxiety can affect memory:
FIELD EXPERIMENT:
- Independent groups (two conditions). Participants heard an argument then either saw a man emerge from the room holding a pen with greasy hands. OR they saw a man holding a knife covered in blood
- They were then asked to identify him from 50 photos. FOUND 33% accuracy for Bood condition VS 49% - Grease conditions. Showing that people in the weapon condition remembered less due to increased anxiety.
BUT
- Because an independent groups design was employed people in the ‘grease condition’ may have had naturally better memories than those in the ‘blood’ conditions anyway
- IF they did this would lover the internal validity and would make any results inconclusive
Relevance of laboratory findings
- Doubts have been expressed about the value of laboratory findings for eyewitness testimonies in the real world because they cannot be generalised.
1. In a lab most people are witnesses rather than victims
2. Situations are less stressful
3. And participants often only have a few seconds to remember faces.
4. Consequences of making a mistake are tivial
Important of laberatory studies
- However, most factors found to be important in laboratory studied are also important in the real world
- If anything, eyewitness inaccuracies and distortions observed in the laboratory underestimate the memory problems experienced by eyewitnesses in real crimes
Deffenbacher
- However, Deffenbacher also found 54% correct face identification when there are low levels of stress compared to 43% for high anxiety conditions
- S0… anxiety and stress can affect memory for identifying the culprit and for details of the crime
Also, it is important to note that
- Some studies have found that emotional arousal can increase the accuracy of EWT
- Christiansen & Hubinette (1993)
- Questioned 58 real witnesses to bank robberies
- Those who had been threatened were more accurate in recall and remembered more
- 15 Months later this continued to be true
Misleading Information and Eye Witness Testimony
Eyewitness Testimony - Misleading Information
- One of the main reasons that EWT is unreliable is because the events witnessed are typically unexpected and as a result eye witnesses may be caught off guard and may not be paying close attention
Loftus and Palmer (1974)
argued that eyewitness testimony is fragile and can easily be be distorted by what happens after the memory has formed
- so they investigated the accuracy of eyewitnesses to see if leading questions distort the accuracy of immediate recall.
Loftus and Palmer (1974) - Procedure:
- 45 participants shown films of traffic accidents
- After each film they were given a questionnaire to describe the accident using specific questions. I.e; ‘How fast were the cars going when they ‘hit?’ then ‘hit’ was replaced by ‘collided’ ‘smashed’, ‘bumped’ or ‘contacted’
Loftus and Palmer (1974) - Findings:
- The group given the verb ‘smashed’ reported higher speeds than other groups (41 MPH). More people in that group also claimed to have seen broken glass when there wasn’t any.
- The group given the word ‘contacted’ estimated the lowest speed (32 MPH)
Loftus and Palmer (1974) - Speed estimates for the different verbs:
Verb/Mean speed estimate Smashed - 40.8 Collided - 39.3 Bumped - 38.1 Hit - 34.0 Contacted - 31.8
Loftus and Palmer (1974) - Conclusion:
- Leading questions can affect the accuracy of people’s memories
- Leading questions can delete the correct information from memory and replace it with false information
- Provides evidence that juries listening to EWT should be very careful about accepting the validity of the account
Loftus and Palmer (1974) - Criticisms:
- Low ecological validity - People may not have taken it seriously and may not have been emotionally aroused.
- Use of Students is not reflective of whole population (lowers external validity)
- Because participants know that it is an experiment they may look for clues as to what is expected of them and response accordingly - making any conclusions invalid (lowering Internal Validity)
Further supporting evidence - Loftus and Zanni
Loftus and Zanni
- Lab Experiments - Car accident
- Then asked did you see the broken headlight OR did you see a Broke headlight
- 17% reported seeing it in condition 1 compared to 7% in condition 2. Showing that memory is affected by misleading information.
Criticisms - Loftus and Zanni
- Again, low ecological validity as conducted in a lab so doesn’t reflect what could happen in real life situations.
- In real life memory may be more easily distorted as in a lab people know they will be tested so pay more attention to the film clip etc than they would in real life situations when the event is unexpected.
Eakin, Schreiber and Sergent-Marshall
- showed participants slides of a maintenance man repairing a chair and stealing money and a calculator.
- Eyewitness memory was impaired by what they read about the event after watching the slides - EVEN when they were warned about the presence of MISLEADING information and told to disregard it! (but lab experiment - artificial - mistakes unimportant)
Evaluation (Misleading Information)
- The research is important as it shows that people’s memories are easily corrupted so this highlights that people have to be questioned carefully to maintain accuracy.
BUT - EWT can be accurate - Yuille and Cutshall (1986)
- used witnesses in real-life serious crimes and found memories to be accurate, detailed and not easily distorted - so EWT can be ACCURATE
- This is also supported by Foster et al (1994) found that if participants thought that they were watching a real robbery then they gave a more accurate description of the robber.
