Factors affecting the accuracy of eyewitness testimony Flashcards
What are the 2 factors that can affect eyewitness testimony?
Misleading information & anxiety
What are the 2 types of misleading information that could affect eyewitness testimony?
Leading questions & post-event discussion
What are leading questions?
Any question in which, because of the way it is phrased, suggests a certain answer
Which key study supports leading questions?
Loftus & Palmer (1974)
What verbs did Loftus & Palmer use in their leading question?
smashed, contact, hit, bumped, collided
What did Lotus & Palmer find?
They found that the estimated speed was affected by the verb used so the accuracy of eyewitness testimony is affected by leading questions.
What explanations did Loftus & Palmer offer for why leading questions affect EWT?
Response-bias factors or the memory representation is actually altered
What was different about Loftus & Palmers 2nd study?
Only used 2 verbs: Smashed or Hit
Asked them if they had seen broken glass (there was no broken glass)
What is post event discussion?
When witnesses discuss the details of a crime of accident, following an incident
Who’s research supports post-event discussion?
Gabbert et al (2003)
Wha did Gabbert et al (2003) find about post-event discussion?
That 71% of participants mistakenly recalled aspects of the event that they did not see in the video but had picked up in the discussion. In the control group where there was no discussion – this was 0%.
What are the strengths of misleading information?
Practical real-world use - e.g., police interviews
What are the limitations of misleading information?
Artificial tasks lacking mundane realism
Individual differences may have been confounding
Demand characteristics reduce validity
Participants may act differently if situation was real
What sort of effects can anxiety have on recall?
Positive and negative
How can anxiety have a negative effect?
Anxiety creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse
Which research supports anxiety having a negative effect?
Johnson & Scott (1976)
What did Johnson & Scott (1976) find?
In the low anxiety condition: 49% were able to correctly identify the man carrying the pen with the grease on his hands.
In the high anxiety condition: 33% were able to correctly identify the man carrying the bloody knife
What is the weapon focus effect?
The tunnel theory of memory argues that a witness’ attention narrows to focus on a weapon, because it is a source of anxiety
How can anxiety have a positive effect?
The stress of witnessing a crime or accident creates anxiety through physiological arousal within the body. The fight- or-flight response is triggered which increases our alertness and improves our memory for the event because we become more aware of cues in the situation.
Which research supports anxiety having a positive effect?
Yuille & Cutshall (1986)
What did Yuille & Cutshall (1986) find?
Those participants who reported the highest levels of stress were most accurate i.e. 88% compared to 75% for the less stressed group
How can we explain the contradictory findings that anxiety can have both a positive and negative effect?
Yerkes-dodson law
What limitations are there for anxiety’s effect on eye-witness testimony?
Weapon focus effect is due to unusualness rather than anxiety/threat (Pickel, 1998)
Field studies (Yuille & Cutshall) lack control
Potential ethical issues
Inverted U is too simplistic
Demand characteristics
