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PSYCH253 Lecture Notes - Eyewitness Identification, Yield Sign, Whodunit

Course Code
Emiko Yoshida

of 3
Social Psychology in Court
Clip rape of Jennifer identified rapist as Cotton, sentenced to life in prison, DNA proved that
other man was real rapist
Why did Jennifer misidentify the perpetrator? How could this be prevented?
Eyewitness is very persuasive (“I saw the person” – no reason for her to lie)
However, memories are malleable and tend to be influenced by various factors
misinformation effect, feedback
People tend to believe confident eyewitnesses
Eyewitness Testimony
Very persuasive but not reliable
Faulty memory is the major cause of wrongful convictions in 180 cases DNA evidence
exonerated someone; 75% of these cases, conviction was because of faulty eyewitness
Jurors and law enforcement professionals rely on eyewitnesses
Study Loftus, 1975, 1979
3 conditions in robbery/murder case:
1. Circumstantial evidence only
2. Circumstantial evidence plus eyewitness declaring “That’s the one!”
3. Circumstantial evidence, eyewitness declaring “that’s the one!” defense lawyer
discredits witness because of bad vision
DV: percentage voting to convict
o 20% voted to convict with only circumstantial evidence
o 70% with circumstantial + eye witness
o Even if witness was discredited, still a high percentage voted to convict
o Eye witnesses tend to be persuasive even when:
Condition is poor
Provided detailed but unrelated information
Why are Eyewitnesses Often Wrong?
Clip Whodunit 21 changes in scenery throughout the clip
Information people notice and pay attention to is also influenced by what they expect to see
Crime usually occurs when you are not expecting it easy to miss critical information when
witness a crime
Research has confirmed that people are poor at noticing the unexpected
Weapon Focus
Focus on a weapon salient
When people pay attention to the salient weapon they have an inability to remember other
details (ex. criminal’s face)
Study 2 conditions: a customer pointed a gun at the cashier vs. handed the cahier a cheque
People paid more attention to the gun than to the cheque
Worse memory of the suspect’s face in the gun condition than in the cheque condition
Misinformation Effect
Remembering wrong information
Study 2 (signs: stop vs. yield) x 2 (asked question about: stop vs. yield)
Car stopped at a stop sign vs. yield sign
“Did another car pass the car while it was stopped at the stop/yield sign?”
Asked which photo they saw
People were only 41% correct when they saw a stop sign but were asked about a yield
sign, or they saw a yield sign but were asked about a stop sign
Denied seeing what they had actually seen
Ps “remembered” seeing the picture that they had never seen
People are unaware about how other factors affect their memory
Class Demonstration
Memorize words given, write as many as possible in one minute
Set #1: Sour, honey, sweet, bitter, heart, taste, good, chocolate, pie
Set #2: mad, wrath, fear, hate, hatred, ire, enrage, fight, anger
“sweet” and “anger” were not in the list of words given, but many people remember them
because they are related to the other words in the list
People sometimes tend to believe that they’ve seen something, but their memory isn’t accurate,
affected by other factors
Memory is malleable and easily influenced by external factors
Juries tend to believe confident eyewinesses
Confidence is not a good predictor of accuracy
Factors that increase confidence are not the same factors that increase accuracy
Other witnesses identifying the same suspect
Being asked the same question repeatedly
These factors have nothing to do with accuracy, but they will increase confidence
Study The Lineup Interviewer’s Feedback
Witnessed a murder, were asked to identify the suspect, everyone made a false
identification (real murderer wasn’t in the lineup)
1. Confirming feedback condition: “Good. You identified the actual suspect”
2. Disconfirming feedback condition: “No. Actually it was suspect #__”
3. No feedback condition
Ps asked how well they could see the suspect in the video, and how sure they are with
the suspect they chose
Results: DV Percentage of people whose certainty was 6 or 7
o People are less confident when they receive disconfirming feedback
o No feedback less than 20%
o With confirming feedback, many more people were confident in their answers
o When people received confirming feedback, they claimed that they could see
the suspect better than in other conditions
o Most Ps denied that hte feedback affected how they answered the questions;
however, they were still affected by the feedback
Judging Whether Witnesses are Lying
Clip The Simpsons Bart in court as witness; how accurate are people at detecting deception?
Research has shown that people are accurate only 54% of the time
Law enforcement agents are no more accurate than college students
It is harder to detect whether someone is lying than we might think
Reducing Error
Provide less time for lineups
Accurate recognition tends to be automatic
Accurate witnesses face “pops out” at them
Inaccurate witness use process of elimination, compare faces to each other
Taking more time and thinking more carefully are associated with making more mistakes