Eyewitnesses Flashcards
Stages of Memory
- Preparation/ Attention Stage: See features or individual
- Encoding Stage: Take note of certain features
- Short-term Memory: Less detail from original encoding
- Long-term memory: similar information but not all able to be retrieved
- Retrieval Stage: Able to recall aspects of memory
What factors can affect how much is encoded in an eyewitness
Inattention and Unexpectedness
- Did they expect something to happen
How can memories change in recall
- Order of events may change
- may embellish certain details
- Fill in gaps that were forgotten
What differences in interviewing techniques can affect the retrieval stage of memory
- Wording of questions
- Another witness recalling memories that you then believe as your own
- Time elapsed since witnessing crime
Types of retrieval
- Recall Memory: Reporting details of a witnessed event (free recall or questions)
- Recognition Memory: Reporting whether what is currently being viewed/heard is the same as the previously seen person/item of interest (is this something you have seen or heard before)
Eyewitness Research: Independent Variables
ESTIMATOR VARIABLES: Present at the time of the crime
- Cannot be changed in field, can be controlled in lab studies
- Eg: Age of witness, lighting, presence of a weapon, intoxication
SYSTEM VARIABLES: Can be manipulated to increase or decrease eyewitness accuracy
- Can be changed, under the control of the justice system to change
- Ex: Structure of interview, type of lineup procedure
Eyewitness Research: Dependent Variables
OPEN-ENDED RECALL AND/OR DIRECT QUESTION RECALL
- Recall of crime/event or Recall of perpetrator
- Can be verbal or written
- Analyzed by amount of info, type of info and accuracy of info
RECOGNITION OF PERPETRATOR
Issues with current Interview Techniques
- Officers commonly interrupt witnesses (switches line of thinking)
- Officers ask short, specific questions (Focuses on one piece instead of full picture, easier to remember whole picture)
- Asks questions in a random order (lack of temporality impacts ability to recall)
- Contamination of co-witnesses can occur
- Ask leading or suggestive questions
Memory Conformity
What one witness reports influences what the other witness reports
Loftus & Palmer: Car accident study
- Participants watched a video of a car accident
- Asked “How fast were the cars going when they _____ each other” filling in the blank with smashed, bumped, collided, contacted
- Faster speeds were reported when smashed was used
- Slower speeds reported when bumped or contacted was used
- Brought back to ask if glass was broken and those who had the word smashed were more likely to say yes
Loftus: Demonstrators disrupting class
- 3 minute video of 8 demonstrators disrupting a class
- Half of the participants were asked “was the leader of the 12 demonstrators male”
- other half: “was the leader of the 4 demonstrators male”
- One week later: “how many demonstrators were there?”
- First half: average 8.85, second half: avg 6.4
What is the Misinformation Effect
Witness presented with inaccurate information after an event will incorporate that misinformation into subsequent recall
What are the hypothesis for the misinformation effect
- Misinformation Acceptance Hypothesis: Witnesses guess at the answer they think the experimenter wants
- Source Misattribution Hypothesis: Accurate and inaccurate memories both recall - however, witnesses do not remember where each came form
- Memory Impairment Hypothesis: Original memory is replaced or altered, original memory is no longer accessible
Standard Cognitive Interview
- Only conducted on witnesses, they must be willing
REINSTATING THE CONTEXT - Put back in situation, what senses are present
REPORTING EVERYTHING - Free recall from beginning to end
- Can add questions if in temporal order and context
REVERSING ORDER - End-beginning
- Allows catching of additional details
CHANGING PERSPECITVE - What might someone else in the room have witnessed
Enhanced Cognitive Interview
Same steps with focus on;
- Rapport Building
- Supportive interviewer behaviour ( don’t interrupt, accept pauses, express attention)
- Transfer of control (let witness lead conversation)
- Focused Retrieval (open-ended questions)
- Witness-Compatibility Questioning (match thinking of witness, same subject)
Why is the enhanced cognitive interview not always used?
Takes time and a specific space
- Ideal but not necessary
What have studies found on describing perpetrators?
- Hair and clothing are most common descriptors
- In staged crimes (know its going to happen) avg 7.35 descriptors
- In real crimes (physiological arousal causes decrease in attention) avg 3.94
- Writing out worse than verbal description
What type of descriptors are accurate vs inaccurate?
Gender and race most accurate
ACCURATE
- Hair color
- Hair length
- Age
- Height
- Complexion
- Type of top
INACCURATE
- Weight
- Eye color
- Color of Footwear
Featural vs configural recognition
- Featural for object
- Configural for faces
Line ups
- Provide evidence that the suspect is the perpetrator
- Made up of foils and suspect
- If suspect is selected it provides evidence against person
- Default values: sex, race, maybe hair color
Similarity-to-suspect strategy
Matches lineup members to suspect’s appearance
- Hair color, eye color, height, weight
- Too similar makes it hard to pick out
Match-to-description Strategy
Distractors have features that were described in initial description
Fair Lineup
Suspect does not stand out from distractors
Assessing Lineup Accuracy
- Correct identification: identify target when present
- False Rejection: Identify no target when target is present
- Foil identification: Identify a foil
- Correct rejection: Identify no target when perpetrator isn’t present
- False Identification: identify target when perpetrator isn’t present
Foil Identification
- Can happen with either target-present or target-absent
- Known to police - the incorrect person will not be prosecuted
- Raises questions about the credible
False Rejection
- May result in guilty suspect going free
- Decreases evidence and likelihood of prosecution
False Identification
Innocent suspect could be prosecuted
- most serious type of identification error
- Increases chance of innocent being prosecuted
Simultaneous Lineup
All lineup members presented at the same time resulting in relative judgement
- One who looks MOST like perpetrator picked
- Mostly issue for target absent
Relative Judgement
Members are compared to one another
Sequential Lineup
Lineup members presented serially to witness resulting in absolute judgement
- Witness decides to move on
- Can’t move backwards
- Don’t know how many options
Absolute Judgement
Members are compared to the witness’ memory of the perpetrator
Lindsay & wells: Lineup identification
- University students watched video-taped theft
- Asked to identify perpetrator from 6 photos
INDEPENDENT VARIABLES - Target: absent or present
- Procedure: simultaneous or sequential
RESUTLS - Sequential and simultaneous even with correct identification
- Greater rate of correct rejection when sequential is used (used in ON)
- Results replicated in real life
Does order of suspect in line up matter
- Studies have shown we look left first
- Foils on left more likely to be chosen
- Should randomize order
Alternative forms of lineups
- Photo arrays: quick, portable, static, less anxiety for witness, don’t have to worry about behaviour
- Video-recorded lineups: can view behaviour, can pause + zoom, see gait, still quick and portable, can edit out bad behaviour
- Show up: only one suspect is presented to the witness
- Walk-by: naturalistic, police bring witness to where suspect is likely to be, anxiety for witness, time consuming
Biased Lineup
The person the police suspect is obvious in some way
- May cause witness to feel pressured to pick that individual
Foil Bias
Suspect is the only lineup member who matches initial description
Clothing Bias
Suspect is the only lineup member wearing clothing similar to perp
Instruction Bias
Police fail to mention that suspect may not be present
Ways to decrease line up biase
- use multiple types of line ups
- clothing and face identification increase chance of correct suspect
Estimator Variable: Age
Older adults less likely to make correct identification and correct rejection when compared to younger adults
Estimator Variable: Race
Subject to cross race effect
Cross-race effect
Witnesses remember faces of people of their own race with greater accuracy than they remember faces of people of other races
Hypothesis that explain the Cross-Race effect
ATTITUDES (not true)
- People who are less prejudiced are better at distinguishing between faces among races
PHYSIOLOGICAL HOMOGENITY (No research to support)
- Some races have less variability in their faces
- All races have same heterogeneity
INTERRACIAL CONTACT
- The more contact you have with other races the better you will be able to identify them
- Exposure at young age important
Estimator Variable: Weapon Focus
- When a weapon is involved, witness’ attention tend to focus on the weapon rather than the perpetrator
- Affects memory for the crime and the perpetrator’s appearance
- explained by cue-utilization hypothesis or theory that weapons are unusual and attract witness’ attention (neither backed by research)
Cue-Utilization Hypothesis
Good Theoretical Explanation - limited support
- when emotional arousal increases, attention capacity decreases (more focused on calming and emotional regulation)
Pickel: Is weapon focus due to unusualness?
INDEPENDENT VARIABLES
- Setting
- Threat
DEPENDENT VARIABLES
- Memory for the perp’s appearance
RESULTS
- Threat played no roll
- Higher attention to weapon when object is unusual to location
Fawcett et al: Expectation vs type of object attention to detail
Accuracy at recalling is highest when the object is expected
- higher with unexpected object than unexpected weapon
Carlson and Carlson: Will some other sort of unusualness offset weapon focus
INDEPENDENT VARIABLES
- Method of aggression: fists, beer bottle, gun
- Facial Distinctiveness: Sticker on perp’s face vs no sticker
DEPENDENT VARIABLE
- Accuracy of memory for perpetrator
RESULTS
- When no sticker: worse accuracy when gun was present
- When sticker present: better accuracy than usual when gun is involved (not total effect)
