MODULE #2 Flashcards
factors that affect eyewitnesses’ performance (2)
(1) Estimator variables
(2) system variables
estimator variables (2)
(1) factors that may affect eyewitness testimony and that are not under the control of the criminal justice system
(2) These variables have to do with the characteristics of the eyewitness or the circumstances surrounding the event witnessed.
system variables
factors that may affect eyewitness testimony and that are under the control of the criminal justice system
Examples of estimator variables (4)
- the emotional state of the eyewitness,
- the amount of attention an eyewitness paid to the event and to the perpetrator,
- the length of time an eyewitness viewed a perpetrator,
- the lighting conditions under which a perpetrator was viewed
Examples of system variables (2)
- the way an interview is conducted o
- the way a lineup is constructed
three stages in memory processing
(1) encoding,
(2) storage, and
(3) retrieval
Encoding (5)
(1) Not all event details are encoded.
(2) When we encounter an event, we selectively attend to and encode a subset of event details.
(3) Selective attention is particularly relevant when the event is complex and extensive, as more details are selected out of attention, resulting in a memory trace that is incomplete.
(4) we don’t simply passively encode stimuli in the environment; we actively interpret our experiences.
(5) Expectations that are formed long before an event occurs may predispose us to remember the event in certain ways.
Storage (6)
(1) Information about a past event is not stored in a veridical videotape-like manner that we can access whenever we need to; it is a compilation of information from a variety of sources that combines to allow us to “know” what occurred at some past time.
(2) information acquired before and after the event influences what we report remembering about the target event
(3) General knowledge that is acquired before an event is experienced can also influence what information is stored in memory
(4) For instance, we tend to use general knowledge to “fill in the blanks” when details in memory are incomplete.
(5) may also use general knowledge to change information that is inconsistent with expectations
(6) we have trouble remembering what we actually perceived versus what we reported having perceived. This could lead to inaccuracies if the prior reports contain errors.
eyewitness’s suggestibility
the tendency of eyewitnesses to be easily influenced by suggestion
eyewitness’s suggestibility
the tendency of eyewitnesses to be easily influenced by suggestion
Retrieval (3)
- the type of question asked during retrieval attempts may have a substantial impact on what is recalled
- The nature of a retrieval cue will affect the kind of information that is retrieved
- A retrieval cue on one occasion may activate a different subset of details than a different retrieval cue that is administered on another occasion.
Situational Factors That May Affect Eyewitness Identification
- Stress/Arousal
- Weapon Focus
Generally, we recall the gist and central elements of emotional events more accurately than we do the gist and central features of non-emotional events. There are at least four possible reasons for this:
(1) events are emotional because they relate to things or include details that we care about, and this leads to better memory for those details;
(2) we tend to rehearse arousing events more than neutral events, and rehearsal enhances memory;
(3) arousing events may activate amygdala-based processing that leads to particularly vivid memories (not necessarily accurate, but memories that are experienced as vivid);
(4) there is a narrowing of attention to the central details of events that are arousing, leading to good memory for the central details at the expense of memory for peripheral details.
Stress/Arousal (2)
- emotional arousal as a physiological response and stress as the subjective interpretation.
- an event is emotionally arousing and an individual subjectively interprets that arousal as negative (stressful) or not (not stressful).
Easterbrook hypothesis
states that as arousal increases, attention to the most salient elements of the event is sharpened at the expense of attention to the less central elements of the event.
Reisberg and Heuer (2007) suggest that the narrowing of attention may not be entirely due to arousal. (2)
- Part of the effect could be explained because the central details of emotionally arousing events are typically unusual in some way, and unusual details command attention.
- Because we have limited attentional resources, some attention is diverted from peripheral details to the central details, leading to improved memory for the central details and impoverished memory for peripheral details.
There are two possible explanations for weapon focus phenomenon (3)
- the presence of a weapon is stressful and frightening to witnesses, and as a result their memory is impaired
- the weapon draws people’s attention because it is unusual or unexpected. We don’t typically encounter people carrying guns in our everyday lives. Thus, our attention is drawn to the weapon and this impairs memory for other details.
- Related to this point, when there is a weapon used in the crime, it would make sense for people to pay attention to where the weapon is pointed to assess their level of danger. As a result, witnesses do not look at the assailant’s face as frequently and later on have more trouble identifying who the real criminal was.
Weapon Focus (3)
- Research has shown that eyewitnesses are significantly influenced by the visual presence of a weapon.
- When a weapon, such as a knife or gun, is present, witnesses’ memory for other details is impaired
- eyewitnesses narrow their attention, spending more time focusing on the weapon and less time on other aspects of the situation, including the physical characteristics of the event and the perpetrator
weapon focus effect
the phenomenon whereby a witness’s memory for details is impaired by the presence of a weapon
Post-Event Factors That May Affect Eyewitness Identification
- Passage of Time
- Misleading information
Misleading information (6)
- can affect the accuracy of an eyewitness’s recall
- reports of eyewitnesses can be influenced by information introduced after the event.
- suggestions implanted within questions can influence the recall of eyewitnesses
- the way in which questions are worded could also influence eyewitness recall
- subtle variations in wording or subtle suggestions implanted in a question or statement about an event can result in substantial variation in the eyewitness’s recall of the event
- There is an interaction between passage of time and suggestion. The more time that passes between a witnessed event and a misleading question or other attempt to implant a suggestion, the more effective the suggestion will be in distorting the accuracy of the eyewitness’s report
Wells, Wright, and Bradfield (1999) delineated three conditions under which misleading information tends to affect the accuracy of eyewitness accounts:
(1) when the strength of the original memory trace is weaker rather than stronger (such as when an eyewitness does not get to observe the event for very long, or when a great deal of time has passed since the event);
(2) when the misinformation is not recognized as being incorrect at the time (such as when the misinformation is about a peripheral detail rather the central gist of the event);
(3) when the misinformation is delivered by a credible source (such as a police officer).
Three explanations for the suggestibility effect have been offered
- Misinformation Acceptance
- Source misattributions
- Memory impairmment
Misinformation Acceptance (2)
- This is the process in which participants guess or respond in a way they think the questioner wants them to respond.
- Because the questioner presented the misinformation or otherwise expressed a desire to hear the misinformation, it seems reasonable to participants that the suggestion is the desired response.
Source Misattributions:
Participants recall both the experienced detail and the suggested detail but cannot remember how each detail was learned, and sometimes inaccurately attribute the suggested detail to the experience.
Memory Impairment
The misinformation impairs participants’ ability to remember the experienced details (that is, it either renders the experienced detail inaccessible or destroys/alters it).
General Principles for Interviewing Witnesses (5)
- Begin the interview by developing rapport with the witness
- Remain neutral and objective.
- Ask open-ended questions that become more structured only if necessary and only as the interview progresses.
- Avoid the use of leading (or misleading) questions.
- Allow the interviewee to control the interview
Two important goals of beginning the interview by developing a rapport
- the witness is being asked to work hard to provide a detailed description of an unpleasant experience to a stranger (the police officer) who is assumed to be an expert on crime. This request will be more successful if the police officer can reduce some of the stress by developing rapport.
- rapport building is also a first step in transferring control of the interview to the witness.
Remain neutral and objective.
Interviewers must not direct the dialogue or reveal their biases.
ways interviewers can inadvertently introduce their beliefs about the event to the witness: (4)
- by selectively reinforcing responses that are consistent with their hypothesis, verbally and non-verbally;
- by ignoring or otherwise discounting statements that are inconsistent with their biases;
- by asking leading questions; and
- by taking control of the interview.
Open-ended questions are recommended for a number of reasons. (3)
- cognitive resources are limited, and if witness resources are taken up listening to the questions (and, perhaps, trying to figure out what the interviewer wants to hear), fewer resources are available to search memory.
- interviewers may not have the cognitive resources needed to listen carefully to the witness if they are thinking about the next question.
- interviewers avoid the problems associated with closed questions.
What is wrong with closed questions? (4)
- The information obtained is likely to be limited.
- asking closed questions discourages witnesses from offering unsolicited information, because they believe the interviewer is only interested in the answers to the specific question.
- Closed questions may foster compliance, with witnesses guessing or providing answers that are consistent with what they think the interviewer wants to hear.
- witnesses may modify subsequent reports so they are consistent with their previous responses to the closed question
Avoid the use of leading (or misleading) questions.
Closed questions are more likely than open questions to contain misleading information, and this could contaminate and compromise subsequent testimony.
Allow the interviewee to control the interview (4)
- The interviewer should talk 20 to 30 percent of the time, and the interviewee should talk 70 to 80 percent of the time.
- Witness should be allowed to provide uninterrupted responses and encouraged to say everything that comes to mind-whether or not it seems trivial or irrelevant
- witnesses should be cautioned not to guess or make anything up.
- Interviewers cannot know all forensically relevant details of a past crime. If the police do not allow witnesses to report all that they can recall about a particular detail, important information may not be elicited (e.g., tattoo, scar, accent).
The Enhanced Cognitive Interview (ECI)
a method of interviewing witnesses to enhance the correct recall of information
ECI relies on two principles
- feature overlap
- multiple retrieval paths
feature overlap
states that effective memory retrieval is related to the degree of similarity (overlap) between the retrieval cue and the original event (also known as encoding specificity)
multiple retrieval paths
recognizes that there are several retrieval paths to an encoded event; if all of the relevant information is not available with one retrieval cue, more information may be available with another retrieval cue.
The ECI is based on four memory-retrieval methods designed to increase recall
1.The witness is asked to reinstate the context of the crime
2. The witness is told to report everything.
3. The witness is asked to report the crime in a variety of orders
4. The witness is asked to report the crime for multiple perspectives
The witness is asked to reinstate the context of the crime (4)
- helps witnesses maximize the amount of overlap between the encoding and retrieval contexts.
- Witnesses are guided to reconstruct the context, including surroundings, emotions, and thoughts.
- It may help to ask them to close their eyes when recalling the crime
- most effective when there is a delay between the crime and the interview
The witness is told to report everything
- Witnesses are instructed to include everything in the report, even partial details and details that seem irrelevant.
- When this prompt is administered, they should be reminded not to guess or make anything up.
The witness is asked to report the crime in a variety of orders (3)
- to report the event in a variety of orders and to report the event from a variety of perspectives.
- Witnesses may, for instance, be asked to report the event from the end to the beginning or from the most memorable point to the end.
- they may be asked to describe the event from a different spatial location (e.g., “What would you have seen if you had been standing across the street?”) or from a different person’s perspective.
The witness is asked to report the crime for multiple perspectives (3)
- Witnesses are asked to imagine what the crime would have looked like from another person’s perspective, such as the perpetrator’s or another witness’.
- They may also be asked to think about what the crime would have looked like from another vantage point, such as from up above.
- This is meant to increase recall.
directs police to use witness-compatible questioning (2)
- Retrieval is most likely to be successful if the details reported are consistent with a witness’s current mental record. So if witnesses are currently thinking about the perpetrator, it is not a good idea to ask about the getaway car.
- First, a question about the getaway car is likely to end their mental record of the perpetrator, perhaps before they have reported all they can recall about the perpetrator. Second, they may answer questions about the getaway car before they have an ideal mental record of it.
reasons live lineups are rare in Canada (7)
(1) the real inconvenience of constructing an adequate live lineup, particularly in smaller communities, where the number of foils (i.e., members of the lineup other than the suspect) that are unknown to the witness is limited;
(2) the suspect has a right to refuse to participate in a live lineup or to request that counsel is present during the lineup procedure (however, the police can conduct a photo lineup or a video lineup without consent of the suspect
(3) photo lineups are less time-consuming to prepare;
(4) photo lineups are portable, making them much more convenient;
(5) photo lineups are static, so the police do not have to be concerned with the behaviour of any member of the lineup that could introduce bias;
(6) the witness may be less anxious about examining a photo lineup than a live lineup; and
(7) all witnesses see the same photo.
Estimator Variables that Affect Eyewitness Identification Accuracy (5)
- passage of time,
- the environment
- duration of the event,
- the race of individuals involved, and
- unconscious transference
Passage of Time (4)
- As with any memory, recall drops off as time passes
- the rate of forgetting is steepest immediately after the event and then levels off
- amount of time that passes between the event witnessed and the opportunity to describe the event or make an identification will decrease the accuracy of an eyewitness account
- eyewitnesses forget things over time and, therefore, accuracy diminishes as more time passes
Environmental Factors (3)
- amount and type of light available at the crime scene affect how well eyewitnesses are able to see and, therefore, how well they are able to perceive the events as they unfold
- distance between the witness and the observed event
- the presence of additional simultaneous activity or other distractors
Duration of Event (3)
- Research on facial recognition suggests a positive relationship between time and accuracy such that the longer witnesses are exposed to a perpetrator, the more accurate their eyewitness testimony will be.
- There is a tendency for people to overestimate the duration of brief events and underestimate the duration of lengthy events.
- witnesses tend to overestimate the amount of time they were exposed to the perpetrator.
- if the perpetrator has a weapon, witnesses will spend even less time observing facial and physical features.
Cross-Race Identification (2)
- there is evidence to suggest that people are better at recognizing the faces of members of their own race than they are at recognizing the faces of members of other races.
- as our contact with members of different racial groups increases, our ability to recognize faces from those racial groups improves.
own-race bias
the phenomenon whereby within-race identifications are significantly more likely to be accurate than cross-race identifications
Unconscious Transference (2)
- inaccurately attributing a face to a different context
- unconscious transference occurs when an eyewitness mistakenly identifies an innocent bystander who was present at the crime scene as the perpetrator
Construction and Administration of lineups
- The belief that the suspect is the culprit increases substantially once that suspect has been selected from a lineup
target-present lineup
If the suspect is the culprit, the lineup is said to be a target-present lineup.
target-absent lineup
If the suspect is not the culprit (e.g., the police made a mistake), the lineup is said to be a target-absent lineup.
Wells and colleagues (1999) identified three broad domains as sources of eyewitness identification errors in lineups that could lead to an incorrect identification of an innocent suspect:
- instructions
- structure
- procedure
Pre-Identification Instructions (5)
- If police instruct the witness prior to viewing the lineup that the perpetrator might or might not be present, inaccurate or false identifications can be reduced substantially.
- instructions to witnesses should include a warning that they are not to guess.
- Asking a witness to select a perpetrator from a lineup places a high degree of demand on the witness
- many will select the individual who most closely approximates the perpetrator.
- Most witnesses feel a desire to assist the police and, therefore, experience psychological pressure to identify someone from the lineup as the perpetrator.
Structure of the Lineup (5)
- lineup should contain only one suspect
- All other members of the lineup (i.e., the foils) should be known innocents
- there should be nothing about the suspect that makes him or her stand out from the foils.
- On the other hand, if the foils look too much like the suspect, it will be impossible to make an identification.
- foils are selected by matching them to the description of the perpetrator.
Administration of the Lineup (2)
- Sequential presentations tend to encourage absolute judgments,
whereas simultaneous presentations tend to encourage relative judgments. - sequential presentation was superior to simultaneous presentation.
relative judgment
involves comparing lineup members to one another and choosing the one who looks most like the culprit.