PSC 153 Lecture Notes - Lecture 7: Ingroups And Outgroups, Flashbulb Memory, Contact Hypothesis

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PSC 153 Lecture 7 Eyewitness Identification and Testimony
Introduction to Eyewitness Testimony
Eyewitness testimony one of the most influential pieces of evidence that can be
brought to a trial
Mock Juror Data (Kassin and Neumann 1997)
Mock trials with weak circumstantial evidence plus either confession or eyewitness
Eyewitness 59% convictions
Conviction 73% convictions
Unfortunately eyewitness testimony is not as reliable as many people assume
8,000 wrongful convictions per year in the US
As of October 2016, 344 individuals exonerated through DNA testing thanks to the
Innocence Project
Eyewitness misidentification was involved in 73% of these cases
Memory Review
Memory mental processes that enable us to retain and use information over time
Encoding transforming information into a form that can be stored in memory
Storage retaining previously encoded information in memory so that it can be used
at a later time
Retrieval recovering from memory information that has been previously encoded
and stored
Interdependent processes
Stage model of memory memory consists of three stages through which information is
Sensory memory 1st stage, registers information from the environment and holds it
for a very brief period of time
Short-term (Working) memory 2nd stage, temporarily holds information so that it
can be interpreted and manipulated
Long-term memory 3rd stage, permanently stores information, making it available
for retrieval and active manipulation when needed
Factors that affect long-term memory:
Depth of processing shallow processing: based on sensory characteristics, deep
processing: based on meaning
Breadth of encoding Simple encoding: repeating information, complex encoding:
creating connections with pre-existing knowledge
Elaborative rehearsal (deep processing and complex encoding) works best
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Encoding Specificity Principle memory is facilitated when the conditions at
retrieval are similar to the conditions at encoding
Type of Retrieval
(Free) recall retrieving information from memory without the aid of cues
Cued recall retrieving information from memory with the help of a hint or a
Recognition correctly identifying information from memory out of several
possible choices
Memory is a reconstructive process, not a video camera
We tend to encode and store the general idea while leaving out the details
At retrieval, we reconstruct on the basis of: existing memory trace, expectancies,
beliefs, current knowledge
This may lead to false memory
Factors affecting eyewitnesses
Eyewitness memory factors intervening during encoding
Stress the relation between stress and performance is curvilinear (Yerkes-Dodson Law)
Depends in part on difficulty of task
When task is simple, stress facilitation
When task is complex, stress inhibition
When it comes to eyewitness memory: stress enhances memory for main stressor, stress
interferes with memory for peripheral details
Weapon Focus Effect if a weapon is present, it becomes the focus of the witness
attention, leaving less resources to encode the perpetrators features or other details
Flashbulb Memory autobiographical episode associated with a particularly meaningful
and/or emotional event
Flashbulb memory is thought to be extremely detailed and accurate, but confidence does
not mean accuracy
Own-race Bias (ORB) Own-race faces are recognized more accurately than faces of
another race
One of the most reliable effects of psychology
The problem of cross-race identification
Among the 344 wrongful convictions uncovered by Innocence Project 80% of
victims are Caucasian, 70% of wrongfully convicted are of a different race
Why does it happen?
Contact hypothesis limited amount of interracial contact = less ability to recognize
other race
Motivational hypothesis people are more motivated to encode in-group faces
compared to out-group faces
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Accurately encoding facial features requires effort
Exerting effort requires motivation
Ultimate motivator is outcome dependency people are more dependent on in-
group vs. out-group members
In-group faces encoded more accurately
Out-group membership reduces own-race recognition
Motivation increases cross-race recognition
High-status cross-race faces are recognized more accurately, low-status own-race
faces are recognized less accurately
ORB occurs because own-race and cross-race faces are more likely to be perceived as
in-group and out-group members, respectively
Factors intervening during storage
Forgetting the inability to recall information that was previously available
Encoding failure insufficient attention
Motivated forgetting suppression/repression
Decay memory naturally fades with the passage of time
Interference forgetting is caused by one memory getting in the way of the other
Factors intervening during storage/retrieval
The misinformation effect misleading post-event information leads subjects to
remember false details of car accidents
Overwriting hypothesis
Source monitoring failure to retrieve the correct source of a real memory
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