Eyewitness Testimony

Eyewitness Testimony

1. Eye witness testimony: The evidence provided to the police by witnesses to a crime . They play a critical role in criminal investigations however the testimony may not be accurate.

2. Factors affecting EWT

   • Misleading information
     • Leading questions
       • Questions that suggest a certain answer. It is believed that the wording of a question can influence how an eyewitness decides to answer it (this doesn't change their memories).
       • Loftus and Palmer - 45 university participants were asked to watch 7 video clips of car accidents. They were then given a questionnaire with the critical question being 'How fast were the cars travelling when they hit each other?'. In the different conditions the verb was replaced with 'bumped', 'smashed', 'collided' or 'contacted'. They found that participants given the word 'smashed' gave the average highest speed of 41mph. The participants given the word 'contacted' gave the lowest average speed of 32mph.
         • Suggests the way a question is worded (leading questions) affects the recall of eye witness testimony.
     • Incorrect information given by the eyewitness after an event. Leading questions and post-event discussion can lead to inaccurate recall.
     • Loftus and palmer - For a second experiment they asked 150 students to view a video of a car crash. 5o were asked the question with the word 'smashed' in it. 50 were asked with the word 'hit' in it and 50 weren't asked at all. One week later they were questioned about the event with the key question being 'did you see any glass? (there wasn't any). They found the 'smashed' condition were more likely to say they'd seen glass (34 vs 6 (control group ) and 7 (hit condition).
     • Post-event discussion
       • Memory can become distorted through discussing events with others or being interviewed multiple times. The reason being that they combine mis-information from the other witnesses with their own memories.
       • Shaw et al - Paired participants with a confederate and watched a staged robbery. They were then interviewed together with the participant and confederate alternating who answered first. When the participant answered first the recall was accurate 58% of the time. When the confederate answered first giving the correct information the recall of the participants was 67%. If the confederate gave the wrong answers recall dropped to 42%
         • Shows that other peoples witnesses of events can influence your memories and how you give your EWT.
   • Anxiety
     • Anxiety has a strong effect on EWT however it can be argued it's both positive and negative.Some psychologists believe that a small increase in arousal can increase the accuracy of memory as you're more alert. High levels have a negative effect on the accuracy of recall ie. violent crimes. The is because the witness may focus on the central details ie.knife and neglect the peripheral details ie. what the criminal looked like.
       • Tunnel theory - When a witness's attention narrows to the source of the anxiety ie. a weapon. Fight or flight response is triggered which increases our alertness and improves memory.
     • Johnson and Scott - Participants were led to believe they were going to be taking part in a laboratory experiment. In the waiting room participants heard an argument in the room next door. In the low anxiety condition a man walked out with a pen in his hand and grease on his fingers. In the high anxiety condition participants heard the sound of breaking glass and a mas emerged with a knife in hand and blood on his clothes. The participants were later asked to identify the man from a set of 50 pictures. Low anxiety group - 49% accuracy whereas high anxiety group - 33% accuracy.
       • Suggests anxiety decreases the accuracy of EWT as participants were focussing on the weapon rather than the man's face.

3. Cognitive interview

   • In order to improve the accuracy of eyewitness testimony cognitive psychologists created the cognitive interview.
     • The Cognitive Interview Technique (CIT) was developed by Greiselman to try and improve the accuracy of witnesses' recall of events during police questioning.
   • Techniques used in Cognitive Interviews
     • The interviewer tries to make the witness feel relaxed and tailors his/her language to suit the witness.
     • The witness is asked to recall everything they can remember, even if it feels irrelevant.
     • The witness mentally reinstates the context of the environment ie. sights, smells and internally ie. mood - context/state dependent cues to try and trigger recall.
     • The witness is asked to recall the events in reverse - allows additional memories to be added.
     • The witness is asked to recall the events from various different viewpoints.
   • Strengths
     • Althrough the cognitive interview was designed for police interviews, it's success has led to it being used by other organisations were accuracy of memory recall is important.
   • Weaknesses
     • It is time consuming, often requiring more time than the officers have operational time for.
     • It's prone to witnesses producing confabulations (false memories) where in correct memories are recalled - some belivee the 'change in perspective' component leads to witnesses speculating about the event.